Turkey Signals: Practical Guide to Turkey Management

TURKEY SIGNALS
A PRACTICAL GUIDE TO TURKEY FOCUSED MANAGEMENT
Credits
Turkey Signals
Publisher
Roodbont Publishers B.V.
Editorial team
Edward Mailyan (main author)
Ton van Schie (co-author)
Marc Heijmans
Cliff Nixey
Nico Buddiger
Ronald Günther
Hafez Mohamed Hafez
Jolanda Holleman
Final editing
Saul Gallagher, Christel Lubbers
Layout
Studio Hiddink
Illustrations
Trudy Michels, Jolanda Hiddink, Dick Rietveld,
Marinette Hoogendoorn
Photographs
Edward Mailyan (532 photographs)
Marcel Berendsen (127 photographs)
And: Kseniya Ageeva (23bl), Marcin Andrzejewski (171br),
Vladimir Arkhipov (37mr, 40tl, 40tr), John James Audubon
(6), Klaus-Peter Behr (190bl, 190 br), Andrey Chaikovskiy
(28br), Roger Culos (8l), Dreamstime, John Anderson (51tl),
Dreamstime, Mikelane45 (51mr), Dreamstime, Tenrook (50b),
Dreamstime, Wouter Tolenaars (70), Sergey Didenko (96bl,
100mr, 154bl), Big Dutchman (74t, 76m), Borregaard LignoTech
(92r), Anton Filinov (13br, 67br), Frantumix company (86ml,
87t), GD (195b), Grendelkhan (22br), Ronald Günther (25tl,
25ml, 99b, 102t, 107m, 118bm, 131tl, 141br, 141tl, 141tr, 143br,
143bm, 144tr, 147br, 150ml, 173, 180b, 185tl, 191tl, 191ml,
191bl), Marc Heijmans (151br, 171bl, 171mr), Hendrix Genetics
(36br, 113bl), Hafez Mohamed Hafez (30r), Huvepharma (21,
167ml, 167bl, 167br), Chris Ilinka (31bl, 31br, 31tr)), Maxim
Karchev (138bl, 138br), Koechner Manufacturing Company
(134mr0, Bogdan Kostromin (40mr, 40mm), Louis Bolk
Instituut (17t), Jesús Carrizo Martín (65bl, 65 br), Marleen van
der Most (129tl, 170t), Evgeniy Nedorostkov (28tl), Nova-Tech
Engineering (43mr, 43ml), Vladimir Nikitin (107tr, 107tl, 115ml),
Frédéric Pradelle (85r), Sergei Primakov (7bl), Henk Rodenboog
(112tr), Roxell (3, 88, 110br), Alexey Sklyar (108tl), Andrey
Stabrov (102m, 102b, 103l), Wim Tondeur (157mr, 159tr, 159br,
159b), Sergey Trofimov (154br), Van Eck Bedrijfshygiëne B.V.
(46), Vasiliy Zyulkin (80bl, 80tr, 190mr), WATT Global Media (9)
b = bottom, m = middle, t = top, l = left, r = right
With thanks to
Marcin Andrzejewski, Arun Kumar Bahl,
Klaus-Peter Behr, James Bentley, Siegbert
Bullermann, Jesus Carrizo, Steven Clark,
Uwe Cramer, Robert Dean Evans, Maarten de
Gussem, Jalal Haddad, Hafez Mohamed Hafez,
Jo Hanssen, Paul van Hoof, Imre HorvathPapp, Chris Ilinka, Dennis van Ingen, Bert
Janssen, Jim Kraft, Wim van Lanen, Stephen
Lister, Yury Lyashenko, Aaron Madsen, Ron
Meijerhof, Marleen van der Most, Carlo Norci,
Frédéric Pradelle, Henk Rodenboog, Jo Sijbers,
Alexey Sklyar, Marcel Stolzenberg, Monita
Verreecken, Albert Vink and the following companies: Management and production team of
DAMATE, Turkey hatchery Hendrix Genetics
and turkey farms Fam. Coumans, Fam. Geraets,
Fam. Jenniskens, Fam. Kicken, Fam. van Meijl
and Fam. Zeelen.
Roodbont Publishers B.V.
P.O. Box 4103
7200 BC Zutphen
The Netherlands
T (0575) 54 56 88
E info@roodbont.com
I www.roodbont.com
© Roodbont Publishers B.V., 2019
Turkey Signals is an edition in the Poultry Signals® series.
ISBN 978-90-8740-262-4
No part of this publication may be reproduced and/or published in
print, photocopy or any other means whatsoever without the prior
written permission of the publisher.
Authors and the publisher have composed the contents of this publication with great care and to the best of their knowledge. However,
the authors and the publisher shall accept no liability due to damage
of any nature whatsoever, resulting from actions and/or decisions
based on the information provided.
The publisher has tried to trace the copyright holders of all the image
material. When a source has remained unmentioned, holders of
rights may contact the publisher.
For more information please check
www.turkeysignals.com
About the author
Edward Mailyan graduated from the Veterinary Department of the Agricultural Faculty of
the Peoples’ Friendship University of Russia in 1998. The following two years he worked
in the Falcon Hospital in Qatar and received his PhD degree in raptor medicine in 2001.
Edward started his poultry career as a veterinarian-microbiologist at Golitsynskaya Poultry
Farm. In the years after he worked as head of the Poultry Veterinary Service of AgroIndustrial Complex Mikhailovskiy. In 2005 he joined Trouw Nutrition International as Senior
Poultry Specialist and later as Deputy Technical Director. Since 2015 he is the Director of
Live Turkey Production at Damate Group. He contributed to the Russian editions of several
titles in the Poultry Signals series as a translator and editor.
Contents
1. Turkey history and market
6
Rodent control
51
Turkey meat
7
Rodent prevention and eradication
52
Global trends
8
Insect control
53
Wild turkey and heritage turkeys
9
Bird control
54
Breeding programs
10
Cleaning and disinfection program
55
Turkey Signals
11
Cleaning the house
56
Signal turkeys
12
Drying the house
57
Farm blindness
13
5. Turkey house climate
58
2. The turkey
14
Microclimate
59
Anatomy
15
Floor temperature
60
Skeleton
15
Air temperature
60
The digestive tract
16
Relative humidity
61
Gut development
17
Comfortable climate
62
Plumage
18
Air quality
62
Rate of feathering
19
Ventilation system choice
65
Turkey physiology
20
Minimum ventilation
66
Senses
21
Airtight and well insulated houses
66
Natural behavior
22
Negative pressure is the key
68
Turkey curiosity
23
Air velocity and trajectory
69
Eating behavior
24
Possible air distribution scenarios
70
Walking behavior
24
Interaction of temperature, RH and air velocity
71
Roosting behavior
24
Inlets
71
Dust bathing, sunning and preening
25
Heating systems
73
Handling turkeys
26
Indirect heaters (boilers)
74
Bird handling procedures
27
Jet heaters
75
Stampeding (piling up)
28
Cooling system
76
Commercial production systems
29
Lighting
77
Stocking density
30
Alternative systems
31
6. Litter management
78
Litter storage
79
3. Hatchery and day-old poults
32
Litter on concrete floors
80
Egg transport and storage
33
Litter materials
81
Setting
34
Wood shavings
82
Candling and breakout
35
Straw
83
Hatching
36
Litter quality
84
Hatched poults harvesting
37
Litter management
85
Poult quality
38
Litter management during rearing
86
Abnormalities
40
Litter management in grow-out
87
Sexing
41
Beak treatment
42
7. Feed and water
88
Claw treatment
43
Phase feeding
88
Snood treatment
44
Adjusting the feeding program
89
Poult delivery
45
Transition from crumb to pellet
90
Feed structure
91
4. Biosecurity for profit
46
Segregation: nutrients separate
92
Farm location
47
Turkey target weight and recovery
93
Farm entrance
48
Whole wheat
94
Equipment and materials
49
Feed safety
95
Vermin
50
Mycotoxins
96
Mold/mycotoxin risks on-farm
97
Temperature during grow-out
142
Nutritional disorders
98
Consequences of poor litter quality
143
Grit
99
Water in grow-out
145
Water
100
Feeding in grow-out
146
Water quality characteristics
101
Behavior in grow-out
147
Biofilm development
102
Dealing with male aggression
149
Water sanitation: key for flock health
103
Preventing pecking – enrichment
150
Adding sanitizers
104
Hens in grow-out: fat deposition
151
Flushing
104
Preparing for slaughter: feed withdrawal
152
Water quality testing
105
Careful catching and loading
153
Loading and transport
154
8. Brooding period
106
Arrival at the slaughterhouse
155
Heaters/brooders
107
Slaughter report information
156
Floor temperature
108
Preparing the bedding/litter
109
11. Gut health
160
Feeder and drinker requirements
110
Signals from droppings
161
Feed availability
110
Cecal function
161
Drinkers
111
Abnormal droppings
162
Pendulum drinkers with float ball
112
Abnormal cecal droppings
163
Poult transport
113
Stomach content
163
Culling day-old poults
114
Gut examination
164
Poult placement
115
Infectious causes of wet droppings
165
Flip-overs
116
Coccidiosis
166
Recovery/sanitary pen
117
Characteristics of Eimeria species
167
Maintaining an optimal climate
118
Anticoccidial programs
168
Supplementary feeders
119
Coccidiosis vaccination
169
Management – the first week
120
Histomonosis (Blackhead)
170
Litter quality during the first week
121
Hemorrhagic enteritis (HE)
171
Necrotic enteritis (NE)
172
Other gut infections
173
9. Rearing period (weeks 2-5)
122
Feeder management
124
Keep feeders clean
125
12. Health and disease
174
Prevention of manure in feeders
126
Diagnosis
176
Prevent water spillage
127
Classification of diseases
177
Clean and cool water
128
Leg problems
177
Protect equipment
129
Respiratory problems
181
Protect climate sensors
130
Sudden death and infectious diseases with high mortality 185
Pecking
131
Transfer from brooding to grow-out
132
13. Vaccination
188
Preparing for transfer
133
Timing
189
Examples of loading/transferring equipment
134
Injection in the hatchery
190
Loading and unloading
135
Injection in the turkey house
191
Eye/nose drop vaccination
192
10. Grow-out (week 5 to slaughter)
136
Spray vaccination
193
Flock management
136
Spray vaccination in the hatchery
195
Monitoring growth and development
137
Drinking water vaccination
196
Sexing errors
138
Water vaccination and behavior
197
Bird inspection
139
Animals for potential culling
140
Index
198
Euthanasia
141
CHAPTER 1
Turkey history and market
John James Audubon, around 1830.
Turkeys are grown commercially in most parts of the world and new turkey operations are being introduced to countries without an established industry. The turkey (Meleagris gallopavo) was originally
domesticated by the indigenous peoples of North America. The wild turkey contains 5 sub-species.
Its territory included all of Mexico, except the extreme southern and western parts, and all over the
United States, south of the Great Lakes and from the Atlantic coast west to Arizona.
The wild turkey is a poor flyer but it can run very
fast and once airborne, can soar for long distances. Settlers in North America consequently found
them quite easy to shoot and decimated entire
flocks. By 1900, only small populations of the once
numerous flocks still existed.
The domestication of the modern turkey owes
much to European influence. It is thought that
the first turkeys were brought to Europe by
Spanish explorers early in the 16th century. A
Yorkshireman, William Strickland, introduced
the domesticated turkey to England. They soon
6
became the favored meat of royalty and nobility.
The domesticated European turkey recrossed the
Atlantic with the early European settlers. A further significant importation was that of a broad
breasted strain brought in from England during
the 1920’s. The North American turkey industry
proceeded to develop much faster than that of
Europe, which suffered shortages of feedstuffs
during and after the Second World War. Since the
1960’s, there has been an interchange of genetic
material and the genetic stock is now very similar
on both sides of the Atlantic.
Turke y S i gnal s
Turkey meat
The turkey can be grown and killed at a range of
ages from 10 to 26 weeks resulting in a wide range
of oven ready weights from 3-20 kg (7-44 lb).
The breeds used for lower weights have very good
breast conformation and have a smaller frame. For
the heavier weights, faster growing, later maturing
breeds are used. Heavy hens are killed at 15-16
weeks and toms at 20-21 weeks.
The turkey is used as a festive meat in some
countries. In the USA it is the main meat at
Thanksgiving time. In the UK it is the meat of
choice for Christmas. Because the breast meat is
the most popular part of the turkey, a trade has
developed in ‘turkey crowns’. A crown is the breast
meat still attached to the breast bone. White meat
(breast) is generally the most expensive part of the
turkey carcass, though there are markets where red
meat (thighs and drums) is the preferred cut (e.g.
Israel, Turkey and Mexico).
In the UK a specialty market exists at Christmas
where the turkey is not eviscerated directly after
killing but ‘hangs’ for a week or so similar to the
technique used with game birds. This process supposedly makes the meat more tender and increases the flavor.
There is no religious taboo about turkey meat. In
countries which do not normally eat pork meat,
and where beef is very expensive, the turkey can
be marketed heavy enough to produce joints
which replicate those seen in beef and pork e.g.
steaks, chops, mince and sausages. It is also seen
as an alternative to the ever popular chicken.
Turkey is included in the Top 10 foods which promote
and maintain ocular health due to its rich zinc content
and the B-vitamin niacin; this combination is known to
combat cataracts.
President Harry S. Truman receiving a Thanksgiving turkey outside the White
House.
1. Tur k e y h i s t o r y a n d market
Turkey meat production compared to other species
Parameter
Chicken
Turkey
Hens
Turkey
Toms
Pork
Beef
Slaughter age, days 36
105
140
173
540
FCR
1.68
  2.55
  2.53
  2.87
  7.60
Daily gain, g (oz)
67 (2)
100 (4)
150 (5)
584 (21)
760 (27)
Carcass yield, %
74.0
74.4
76.0
71.0
48.0
Greenhouse gas
emissions,
kg CO2/kg
4.4
  4.2
  4.5
12.1
27.0
Source: AGRIFOOD Strategies, 2015; Newcastle University, 2014
The turkey and Thanksgiving
Thanksgiving is celebrated on the fourth Thursday of November
in the United States. It originated as a harvest festival. For over 50
years, the National Turkey Federation has presented the President
of the U.S. with a live turkey and two dressed turkeys in celebration of Thanksgiving. Harry Truman was the first president to receive
this honor in 1947. Each year, the live turkey is ‘pardoned’ by the
president.
7
Global trends
Emerging markets
In the Middle East the demand for turkey products is increasing. Paired with a strong economy
this means that prices are good and the industry
is slowly growing. South-East Asia has tremendous potential, being 44% of the World’s population. Even a moderate increase of market share
will trigger a significant boost of import volume.
In these areas, turkey meat fits perfectly with
the local tastes and cooking traditions, however,
the low average income of the population still
restrains an increase in consumption growth as
seen in other markets. In some Chinese provinces
there is a strong and growing demand for smoked
shanks and wings, and the Indian market, with its
ban on beef and otherwise limited pork consumption, is a market with huge future potential.
The global demand for turkey meat has significant
potential for growth. The current global turkey
meat production of 5.6 million MT/year makes up
only 5.2% of total poultry meat production.
Historically the bulk of turkey production is
located in two regions: North America (USA,
Canada) and Europe. However, growing markets
are increasingly becoming players; the most
impressive growth has been seen in Russia and
Spain. Over the last ten years production in Russia
increased almost tenfold. This has raised them
from the 9th to 6th position in the global turkey
producers list.
Consumption in Russia has increased from 0.4 kg
to 1.7 kg (14 oz to 4 lb) per capita and is forecasted to reach 4 kg (9 lb) by 2026. The consumption
in North America has been stable for several years
at 7.7 to 8.0 kg (17 to 18 lb) per capita.
The growth of turkey meat consumption is mainly
due to:
• Historical use of whole turkeys as a holiday
meal in countries with highly developed economies.
• Use of turkey meat in sausages, ham and delicacy products for retail and food services.
• The increasing competitiveness of turkey, pricewise, compared to beef and pork.
• Growth of the Muslim population in countries
with an otherwise high pork consumption.
• Increasing demand among the middle class
for healthy products with low fat/high protein
content.
Turkey
Chicken
110 eggs per year
325 eggs per year
Turkey eggs are full of nutrients and used to be a
menu staple in North America. When Europeans
brought turkeys back from America in the 16th
century, turkey eggs became popular to eat.
They are rarely consumed now, mainly because
they are too expensive to produce compared to
chicken eggs: it takes seven months for a turkey
to start laying and she will only produce 110 eggs
in one lay cycle (26 weeks of production).
Country
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2650
1
USA
2834
2569
2560
2627
2707
2633
2611
2552
2713
2728
2
Germany
436
438
478
467
464
458
469
465
487
465
468
3
Poland
100
100
100
100
129
129
145
162
179
332
380
4
France
449
419
405
398
387
340
378
353
393
330
340
5
Italy
311
305
298
309
322
311
310
313
332
308
290
6
Russia
29
32
48
56
78
98
109
150
226
231
271
7
Spain
25
26
129
149
174
157
159
171
193
221
232
8
Brazil
465
466
337
305
442
364
372
327
367
390
181
9
Canada
180
166
158
159
161
168
168
171
183
171
168
10
UK
135
157
162
171
196
187
172
181
169
171
157
The USA is the largest producer of turkey meat in the world.
8
Turke y S i gnal s
Source: AGRIFOOD Strategies
Global turkey meat production, 2008-2018 (thousands of MT/year)
Wild turkey and heritage turkeys
The wild turkey (M. gallopavo) is indigenous to
much of the eastern and southwestern US,
northern Mexico, and southeastern Canada.
The ocellated turkey (Agriocharis ocellata or Meleagris
ocellata) is considerably different in size and coloration and thought to be a completely separate species. It is native to the Yucatán peninsula of Mexico.
The ocellated turkey is more resistant to domestication than the gallopavo subspecies, but nevertheless
Spanish explorers noted that it was among the
turkeys kept in pens by the Aztecs.
It is now rare in the wild but can be seen in some
zoos around the world.
Feather color
Various sub-species of M. gallopavo carry different
feather genes. The inheritance of feather color is a
complicated subject. In the past, varieties of turkey
were created, distinguished mainly by feather color.
Examples are Bronze, Norfolk Black, Bourbon Red,
Slate and Buff. These and other varieties are being
maintained by enthusiasts in both North America
and Europe, particularly the UK. Exhibition competitions are held at agricultural events and specialist
poultry shows.
The original domesticated turkeys were colored
bronze, the dominant feather color being black,
with the tips of the feathers overlaid with iridescent
red-green bronzing and some feathers having terminal edging and barring in white. Because of the
difficulty in removing all the small developing black
feathers, which then spoiled the appearance of the
carcass, the white feathered turkey now completely
dominates the industrial market.
However, alternative premium markets have been
developed using black or bronze feathered birds,
using the colored feathers to identify them as having a traditional farm produced background.
A heritage turkey retains historic characteristics that are often no longer present in
commercial turkeys. There is a lot of interest
in heritage turkeys. More than ten different
turkey breeds are classified as heritage
turkeys, including the Auburn, Buff, Black,
Bourbon Red, Narragansett, Royal Palm,
Slate, Standard Bronze, and Midget White.
These breeds are defined and recognized
by the American Poultry Association in the
Standard of Perfection.
Heritage turkeys are said to be richer in flavor
than the commercial breeds, but of course
have a much slower growth rate.
Painters: A.O. Schilling: White Holland (1927),
Black (1937), Broad Breasted Bronze (1943).
L.A. Stahmer: Bourbon Red (year unknown),
Narragansett (1930).
Narragansett
1. Tur k e y h i s t o r y a n d market
Black
Bourbon Red
White Holland
Broad Breasted Bronze
Source: WATT Global Media
Heritage turkeys
9
Breeding programs
After World War II, breeding companies aimed to
develop bigger, more fertile and faster-growing
turkeys. They were successful, perhaps too much
so, as by the 1950’s, turkeys were becoming so big
that the birds were having problems mating. The
first response was to build little saddles for the
hens.
Eventually, artificial insemination techniques were
developed. Without artificial insemination the
modern turkey industry would be non-existent.
The current breeding programs are based around
breeding specialized lines selected for reproduction to provide the parent hens. These are then
crossed with toms from lines which have been
selected mainly for growth rate and breast conformation.
In all lines, fitness, robustness and mobility are
key traits for improvement because it is important
for the birds to survive a full breeding season.
The relative selection pressure on reproduction
or growth rate differs for the various market segments that commercial turkeys are designed for.
Female domestic turkeys are referred to as hens,
and the chicks are called poults or turkeylings.
In the United States, the males are referred to as
toms or gobblers, while in the United Kingdom
and Ireland, males are stags.
In this book the terms hens, toms and poults are
mainly used.
The future of turkey breeding
In evolutionary terms, the turkey is recently
domesticated. Breeding programs have only been
in existence for less than 100 years. With the new
techniques now available, progress in reducing
the cost of production should continue at a faster
pace than will be achieved with other meat producing animals. Turkey meat consumption should
therefore be expected to increase around the
world in future years.
Genomics in turkey selection
The turkey genome project published the sequence of a hen named Nici in 2010. The turkey
was the fifth farm animal to have its genome
sequenced, following the pig, cow, sheep, and
chicken. In a joint project between both turkey
breeding companies and several universities and
research institutes, over 5 million differences on
the genome were identified between different
individual turkeys. Breeding companies have
implemented technology within their breeding
programs to use a subset of these differences to
quantify variation between breeder candidates
and identify the turkeys with the best genetics in the most accurate way. This technology
is used to improve traditional quantitative traits
(e.g. body weight and feed conversion), but also
allows implementation of difficult to measure
or new selection traits (welfare, meat quality,
behavior, robustness, disease resistance etc.) in
the genetics program.
♂
♀
1 day
1 week
♂ 50 g/2 oz ♂ 180 g/7 oz
♀ 50 g/2 oz ♀ 170 g/6 oz
10
3 weeks
5 weeks
7 weeks
9 weeks
11 weeks
♂ 750 g/25 oz
♀ 650 g/23 oz
♂ 2 kg/4 lb
♀ 1.5 kg/3 lb
♂ 4 kg/9 lb
♀ 3 kg/7 lb
♂ 6 kg/14 lb
♀ 5 kg/11 lb
♂ 9 kg/20 lb
♀ 7 kg/15 lb
Turkey signals
tions without distractions. The more active you
are in the turkey house the more you disrupt the
birds’ behavior, causing relevant signals to be lost.
Make sure you pay attention to all the birds and
all areas of the house. The sickly bird you overlook
in the corner may be the clue to a disaster you
could have avoided.
Your turkeys will tell you a great many things
through the signals they send out in both their
behavior and physical characteristics. This is precisely what Turkey Signals is all about. You want to
identify irregularities as soon as possible in order
to mitigate further problems, and where you can,
recover from such issues.
Turkey Signals is not a textbook full of tables,
standards and guidelines. The main aim of this
book is to attune you to the signals your birds are
providing.
There are two important things to remember: the
turkey is always right, and the only one who can
make decisions is yourself. This book is just an aid
and everyone who has worked on it hopes that it
will benefit your birds and help you understand
what they are telling you.
The book follows the operations on a turkey farm.
You’ll pick up a lot of signals during the daily
routine of feeding, removing dead and abnormal
birds, and adding extra litter. But make sure you
also leave some time to complete some inspec-
Look-Think-Act
The red thread running through this book is ‘look,
think, act’. Often turkey farmers are so involved
in their business that they can’t see the forest
for the trees. Open your mind to new things, be
critical, and don’t be afraid to change your plans!
In short, keep asking yourself: Is what I’m seeing
normal or should it be different? Ask the following
questions about everything you see:
1. What am I seeing, hearing, smelling, or feeling? What is my flock signaling?
2. Why is this happening? Is there an explanation?
3. What should I do? Can it wait or should I take
immediate action?
♂
♂
♂
♀
♀
13 weeks
15 weeks
17 weeks
19 weeks
21 weeks
♂ 12 kg/26 lb
♀ 9 kg/20 lb
♂ 14 kg/31 lb
♀ 10 kg/22 lb
♂ 17 kg/37 lb
♀ 12 kg/26 lb
20 kg/44 lb
23 kg/51 lb
11
Signal turkeys
There will always be some vulnerable birds in a
flock. They will be the first to suffer from disease,
lack of water or other shortcomings. These are the
signal birds, they are the first ones to tell you that
something is wrong; pay attention to them, and
you will be peering into your flock’s future. Signal
birds will also tell you if an infection is looming;
catch them early and you can save yourself a lot of
hardship.
Always walk quietly without scaring the birds.
Weak and sick birds often gather in corners of the house.
Risk areas
In every turkey house there are areas where you
can expect problems. Places you know could pose
a risk should be a permanent part of your daily
inspections. Make improvements if there is something you can do to mitigate these risks. Examples
of such places are corners, draughty areas, the litter under the drinkers and feeders, and so on.
Critical times
There are certain times of the day, season or cycle
that can be particularly risky. Feeding time is an
example: are the feeders and the weigh scales working properly? But critical times can also be longer
periods of time. Winter is a critical time as it is
more difficult to keep the climate in the house and
the litter in optimal condition. Moisture is harder
to remove, leading to a whole host of issues. In
the summer, heat stress lies in waiting. Be vigilant
and you can beat the conditions.
LOOK-THINK-ACT
What happened to this bird?
Sometimes you see something that you can’t easily explain.
In this case a ruptured air sac in the body resulted in the air
moving to other places under the skin. You can separate the
bird, carefully puncture the skin with a needle and push the
air out. If the bird is developing well - there is nothing wrong
with keeping it in the flock till slaughter. If it is weak and
retarded - cull it.
12
Turke y S i gnal s
Farm blindness
You can only recognize an irregularity if you know
what is normal. You will learn what is normal by
observing as often and as objectively as possible.
But be aware of the dangers of farm blindness!
Farm blindness is when you see the situation on
your own farm as the norm; limit farm blindness
by talking to colleagues and advisors, and by visiting other turkey premises.
How to observe turkeys in a structured way
1. Listen to the sounds inside the house before
entering.
2. Smell the air in the house.
3. Watch the flock’s behavior, no matter what you
are doing in the turkey house.
4. Dedicate some time every day for observation
only.
5. Look at the whole flock, at the individual turkeys, and then back to the flock as a whole.
6. Have a walk routine. Start along the right wall,
then return past feed line or drinkers, then
return along another feed line and then back
up the other wall of the house.
7. Pay particular attention to the appearance
of droppings.
8. Look at different times and in different circumstances.
9. At regular intervals, stand still and get down to
bird level.
10. Identify critical times, susceptible birds and
risk areas.
11. Do not spend too much time in each location
inside the house - avoid birds overcrowding
around you.
Use all your senses
If you only look out for technical aspects (growth, feed and water
consumption, etc.), you may miss other important signals from the
turkeys and their living environment. Always use all your senses. Even
before you enter the turkey house, you can hear if the birds sound
different. When you go in, you’ll smell whether the climate in the
house is OK or if there is a problem with the manure or the ventilation.
Use your eyes and ears to see and hear how active the birds are and
whether they are reacting less or differently to your arrival than usual.
Also, use your senses to observe the temperature or presence of
draft in the house. Every irregularity needs to be attended to.
Signs humans can’t see
Aids such as an infrared camera show what the human eye can’t see.
This roof is not properly insulated. The blue parts are cold. Result:
condensation forms, possibly dripping down onto the floor.
Limit farm blindness by talking to colleagues and advisors.
1. Tur k e y h i s t o r y a n d market
13
CHAPTER 2
The turkey
A turkey is not a BIG chicken. Chickens and turkeys display fundamental differences and these
predetermine the way they are fed and raised. If you have poultry farming experience and think you
can simply switch from broilers to turkeys – then that’s a worrying delusion! You will be surprised
how different these species are, how much more attention and care turkeys require, and how stress
susceptible and unpredictable they can sometimes be.
The turkey has many characteristics that distinguish it from other fowl. The unmistakable snood,
caruncles, head coloring and beard truly set it
apart.
As the turkey gets older and heavier the costs
incurred increase. Therefore the economic risk of
turkey farming towards the end of the production
period increases. Understanding the turkey and its
characteristics is important in order to know how
to deal with them.
The snood is the most obvious difference between a turkey poult and broiler chick.
14
Turke y S i gnal s
11
Anatomy
1
9
12
10
2
25
13
24
3
23
22
4
21
5
20
14
15
6
16
17
8
7
18
1.
2.
3.
4.
5.
6.
7.
8.
9.
Skeleton
1
2
9
4
3
Head crown
Eye
Snood (dewbill)
Wattle (dewlap)
Minor caruncles
Beard
Spur
Shank
Neck
19
10. Major caruncles
11. Tail
12. Nostril
13. Beak
14. Breast
15. Keel
16. Hock joint
17. Toe
18. Toenail
19. Foot
20. Saddle
21. Wingbow
22. Back
23. Shoulder
24. Cape
25. Ear
10
5
8
11
7
23
6
22
12
21
20
14
15
17
18
2. Th e t u r k e y
13
16
19
1. Cranium
2. Eye socket
3. Nasal captivity
4. Nostrils
5. Cervical vertebrae
6. Thoracic vertebrae
7. Elbow
8. Radius
9. Metacarpus
10. Ulna
11. Humerus
12. Pelvis
13. Tailbone
14. Ischium
15. Pubis
16. Femur
17. Tibiotarsus (Tibia+Fibula)
18. Tarsometatarsus
19. Knee joint
20. Sternum
21. Clavicle
22. Coracoid
23. Scapula
15
The digestive tract
The roughage that the turkey eats is processed
mechanically (gizzard) and chemically (proventriculus/small intestine) in the digestive system to
break it down into small components.
Unique to birds is the antiperistaltic action of the
intestine. The antiperistalsis or duodenal reflux
action of the poultry digestive system improves
digestion. Gastrointestinal contractions (motility)
move ingesta through the gastrointestinal tract,
reduce the size of swallowed feed components and
mix ingesta with digestive secretions (enzymes,
Beak and oral cavity
Saliva in the oral cavity contains
enzymes that trigger digestion and
helps the feed travel onwards.
Esophagus
A flexible tube from the mouth to the
gastrointestinal system.
acids). The amount and type of motility stimulated
by feed in the intestine varies depending upon the
type of nutrients ingested. Thus, individual nutrients can have a major effect on gastrointestinal
motility. Slowing contractile frequency or stimulating duodenal refluxes slows the passage rate. This
exposes the intestinal contents for a longer period
to gastric digestive enzymes. Fasting or darkness,
also result in increased digestion. In nature, this
would be beneficial when a bird is unable to find
its feed (feed availability, darkness).
Ceca
The ceca are two blind sacs at the junction
between the small intestine and the colon.
Together with the colon, the ceca act as sites for
absorption of water and short chain fatty acids
produced in microbial fermentation. They are
emptied twice a day.
Pancreas
A very important organ that
secretes enzymes for carbohydrates, fats and proteins
digestion. The pancreas is
attached to each side of
the duodenal loop and lies
between the two arms.
Crop
Temporary storage that contains lactic
acid-producing bacteria for initial fermentation of the feed.
Proventriculus
In the proventriculus (glandular stomach) the feed
is mixed with gastric acid and digestive juices in
a low pH environment. The acid stomach contents kill a large number of harmful pathogens.
Large intestine/Colon
The turkey’s large intestine is very short. Its
only function is water
absorption.
Cloaca (vent)
This is where the residual material
from the digestive process is mixed
with uric acid, which is the white
fraction in the droppings.
Gall bladder
Excretes bile to the intestines, a dark green
fluid that aids the digestion of fats in the small
intestine.
Liver
The liver is - amongst others - responsible for
bile formation, the metabolism of carbohydrates,
lipids and proteins, storage of glycogen, fat and
fat-soluble vitamins and detoxification.
Gizzard
In the gizzard (muscular stomach) the feed is
ground up finely and further mixed with the
gastric juices.
16
Small intestine
In the first section (duodenum) the gizzard content
is mixed with bile salts and digestive enzymes.
The nutrients are absorbed by microvilli of the
middle and final sections (jejunum and ileum).
Feces
The feces consist of waste
(dead intestinal cells and
bacteria) and undigested feed,
and are mixed with the uric
acid in the cloaca. The main
intestinal feces are a rounded,
brown to grey mass topped
with a cap of white uric acid.
Cecal droppings look different:
brown colored with a more
homogeneous, more viscous
consistency.
Turke y S i gnal s
Gut development
The young poult has not yet developed its own gut
microbiota and picks up all kinds of bacteria, both
good and bad. Pathogens are continually trying to
gain access. If poults do not receive appropriate
brooding management or feed intake does not
increase at a normal rate, development will be
impaired, resulting in a poorly functioning gut.
Besides the feed, don’t underestimate the effect of
stress on gut health.
In nature, the poults obtain microbiota from the
hen and her environment. The absence of the hen
on a farm is a risk that is often underestimated.
The balance of the poult is upset if it goes without
feed and water for a longer period so this must be
guarded against. Some people advocate probiotics from a day old (sprayed or via drinking water),
often with strains of vegetative Lactobacillus or
Bifidobacterium spp. or spored Bacillus spp.
Balance
The balance of the microbiota in the gut can be
affected by factors such as:
• Periods of high challenge (e.g. feed change
over and vaccination)
• Feed (quality of raw materials, crude protein
level, digestibility, presence of mycotoxins)
• Poor hygienic conditions (environment, feed,
water)
• Microclimate (temperature, humidity, noxious
gases)
• Brooding conditions (starvation, stress)
• Infections with viruses, bacteria, parasites
Stress causes liquid droppings
In the case that a bird is stressed (for one reason
or another), a higher number of cecal droppings
(or sudden change in consistency), are excreted. Cecal droppings have undergone a bacterial
transformation in the cecum, which results in the
droppings having a higher moisture content. There
is a close relationship between stress level and
water intake. Water intake in turkeys with elevated
corticosterone concentrations (stress hormone)
increases on average by 88%. The amount of water
consumed and excreted can therefore be a useful
parameter for indicating stress in birds.
2. Th e t u r k e y
Natural barriers of the gastrointestinal tract
goblet cell
food particles in
digestive track
bacteria
intestines
mucous membrane
epithelial cells
bloodstream
lymphoid tissue
tight junctions
between epithelial
cells
liver
(blood filtration)
immune cells
intestinal
tissue
lymphoid node
You have to realize that inside the gastrointestinal tract is in fact the outside
world! The gut has 5 biological barriers for the bird’s protection against various
negative influences.
1. competitive microbiota
2. mucous membrane with mucus producing goblet cells
3. tight junctions between cells
4. liver (blood filtration)
5. lymphoid tissue
Assessing the moisture content
1. Manually
Pick up a dropping and squeeze it.
In this photo you can see that the
pellet contains water. If it drips when
you squeeze it, it is too wet!
2. Paper
Lay out paper in the brooding house
to observe fresh droppings. If large
water rings appear round the droppings, as shown in the photo, then
that is a strong indication of impaired
gut health.
3. Moisture meter
You can check the moisture content
of droppings quickly and objectively
with a handy device.
17
Plumage
The great majority of domestic turkeys are bred to
have white feathers (recessive gene) so that their
pin feathers are less visible when the carcass is
dressed. Feathers have a function in body covering, insulation, waterproofing, flight, protection,
display and recognition. A mature, fully grown
turkey has between 3,500 and 6,000 feathers.
Voluminous feathers cover the breast, wings, back,
body and tail of the bird. Feathers account for
approximately 4.2% of the total body weight in
turkeys at slaughter age.
1 cm
5. Filoplumes - small hairlike feathers occurring
among the contour
feathers, associated
with sensory receptors.
Bristle
Filoplume
(hair-like)
Contour feathers
(tail feather)
Contour feathers
(flight feather)
2 cm
1. Vaned
or contour primary flight
feathers of the wing and tail.
Contour feathers
1 cm
2. Contour secondary coverts
create a gradual aerodynamic slope where the body
parts meet.
Brown or bronze-feathered varieties are also raised as
well as other color varieties. Often to clearly identify that
these are the product of alternative production systems.
18
Down
6. Bristles - short and stiff
feathers sensory in nature, are found around
eyes and near the base
of the beak.
Semiplume
1 cm
4 cm
3. Down - loosely structured feathers helping to
trap air near the bird’s
body for warmth.
4. Semiplumes - loose &
fluffy feathers concealed
under contour feathers
that help with insulation.
Turkeys have a ‘beard’ located in the chest area. It’s comprised of so-called meso filoplumes. Beards are most
commonly seen in toms but may also occur in hens.
Turke y S i gnal s
Rate of feathering
The rate of feathering is an indicator of the bird’s
growth and maturation. The feather condition is
a good indication of a turkey’s state of health.
Feathers may be dry and brittle or sleek and
smooth, dirty or clean and variations in between.
Factors involved in feather condition are nutrition,
management and disease. Young turkeys undergo
three molts before acquiring a stable plumage.
From 8-20 weeks the birds are always growing new
feathers with new sets coming in at 8, 12 and 16
weeks of age. Different parts of the body molt at
different times. It is also a gradual process within
separate areas so that the turkey is never without
insulation over its whole body.
Signals from feathers
New feather formation and shape can be an indicator of problems with management. Nutrition
and health can influence rate of feathering as well
as feather structure, color and molting. Amino
acid balance and especially deficiencies of TSAA
(total sulfur amino acid) will influence feathering
in young poults. Deficiency of vitamins and certain
trace minerals also induce characteristic feather
abnormalities, as does the presence of dietary
mycotoxins.
Lysine deficiency can easily be spotted in colored
breeds by a high incidence of white feathers. If
poults are brooded at too high a temperature, it
results in primary wing feathers not lying flat to
the body, and often with broken ends. This condition will stay with the turkey for the rest of its life,
a condition known as split wings.
5-week-old poult
8-week-old poult
With normal growth, an 8-week-old poult will have lost most of the
down from its head, producing the characteristically clean turkey head.
A ‘helicopter’ appearance of the wing feathers indicates that these poults
most likely experienced too high temperatures during the brooding period.
Some common causes of feather abnormalities
Plumage problem
Possible reason
Uneven feather growth,
Protein, amino acid imbaabnormally long primary
lance.
feathers, feathers not lying
smoothly
Frizzled and rough
Zinc, niacin, pantothenic
acid, folic acid, lysine
Black pigmentation in
breeds with red and
brown feathers
Vitamin D
Depigmentation
Copper, iron, folic acid
Bold elbows or ruffled feathers are first signals of early stage dysbacteriosis,
malabsorption syndrome and/or poor nutrients absorption from the gut.
2. Th e t u r k e y
19
LOOK-THINK-ACT
Which one is the hen?
Two turkeys at the age of 12 weeks. The tom’s head is coarser than
that of the hen and the caruncles of the tom are more developed.
So, the left one is the tom and the right one the hen. But other sex
characteristics, such as courting behavior, are easier to identify.
snood
wattle
caruncles
•
•
•
20
Caruncles: Fleshy bumps on the head and neck of both toms
and hens. Sexually mature toms may have large caruncles with
bright colors, which are attractive to hens. Large caruncles or
colorful bright ones indicate high levels of testosterone.
Snood: Hanging over a turkey’s beak is a long flap of flesh called
the snood. During courtship, the snood enlarges and becomes
red as it fills with blood in the tom.
Wattle: This is a flap of red skin that hangs from the chin.
Toms with large wattles are more attractive to hens.
Turkey physiology
Turkey breeds vary largely in their growth rate
depending on the intended market. The slowest
growing breeds are used for niche markets, the
medium growth rate breeds for the oven ready
market, and the heavy breeds for the further processing market. Turkeys can be marketed as early
as 10 weeks and the niche market birds may be as
old as 26 weeks before being killed.
There is a large difference in the speed of growth
between the sexes of the same breed. The toms
will be about 50% heavier than the hens at
18 weeks of age. Commercial hens can weigh
between 9 and 12 kg (20 and 26 lb) when fully
grown. Commercial toms can weigh between 16
and 23 kg (35 and 51 lb). Under commercial conditions they are usually kept separately.
An experienced farmer can differentiate the gender
through physical appearance as early as 7-8 weeks
of age. The differences are very clear by 10 weeks
of age. Toms are longer in the leg and have a thicker leg bone and joints than hens.
The tom’s head is broader and coarser than that of
the hen. The breast conformation is better in the
hen and the keel bone less pronounced, wattles in
the toms are clearly seen.
Other breeds of domesticated turkeys, including
Heritage breeds can be much smaller, weigh far
less and have average life spans of 10 to 12 years.
Turkeys’ normal body temperature is 41.5°C
(106°F), but it can go as high as 42°C (108°F), with
young turkeys registering between 39°C (102°F)
and 41°C (106°F).
Curious features: caruncles
Characteristic are the red, fleshy stretches of skin
and bulbous growths located around the head and
neck region. Both sexes of turkey possess these
so-called caruncles, but they are more pronounced
in the tom. They are often of bright colors (red,
blue, white) and can be present on the head, neck,
throat, cheeks, around the eyes of some birds, on
combs, crests and other structures.
It is believed that the caruncles also play a role in
thermoregulation, making the blood cool faster
when flowing through them.
Turke y S i gnal s
Senses
All birds have five senses. Turkeys rely more
strongly on three of the five. Due to their sharp
vision and hearing, turkeys are very reactive to any
external signals.
3. Touch
Turkeys are highly sensitive to
touch in areas such as the beak
and feet. This sensitivity is useful
for obtaining and selecting feed.
The touch is not limited to just
the bird’s extremities. The texture
and size of different feeds are
determined by the turkey’s beak
and tongue; playing an important
role in the sense of touch.
4. Smell
Turkeys do not have a highly
developed sense of smell.
1. Vision
Turkeys have superb vision, but it is limited to
bright light intensities. They have poor vision
during twilight and darkness. Due to the location of their eyes, they have difficulties to assess
distances of slow-moving objects (e.g. observers) which will lead to a synchronical shaking of
heads to get a stereoscopic impression. This
should not be mistaken as a synchronical head
shaking in case of upper respiratory distress.
2. Hearing
Turkeys have excellent hearing. They have small
holes in their head located behind the eyes.
Turkeys have a keen sense of hearing and can
pinpoint sounds from a mile away. Turkeys can
hear lower-frequency and more distant sounds
than humans.
5. Taste
Their sense of taste is believed to
be underdeveloped. They have
fewer taste buds than mammals
and can detect salt, sweet, and
bitter and acid tastes. Turkeys
don’t like bitter tastes and react
on them far more strongly than
chickens do.
Turkey talk
Just like humans, turkeys vocalize to communicate. It is estimated that turkeys have a vocabulary of over 30 different
calls. Each sound has a general meaning and can be used
for different situations. Toms are notorious for their gobble,
which unlike other calls, is given with a fixed intensity.
2. Th e t u r k e y
21
Natural behavior
When planning a turkey house layout and choosing the equipment, it is necessary to consider the
turkeys’ natural habits. Wild turkeys can fly for
short distances at up to 85 km/h (53 mph) and can
run at 30 km/h (19 mph). Young domestic turkeys
fly short distances, perch and roost. This behavior
becomes less frequent as the birds mature, but
adults will readily climb on objects such as bales
of straw, drinking/ feeding lines. Young birds perform spontaneous, frivolous running (‘frolicking’)
which has all the appearance of play. Commercial
turkeys show a wide diversity of behavior including
‘comfort’ behavior such as wing-flapping, feather
ruffling, leg stretching and dust-bathing.
Social behavior
Turkeys are social and become very distressed
when isolated. Many of their behaviors are socially facilitated: behavior by one turkey stimulates
similar behavior in others. Adults can recognize
‘strangers’. Placing an alien turkey into an established group will result in pecking and fighting
to redefine the ‘pecking order’ within the group.
At times this can be fatal. Spurs are used for protection and defense of territory from other toms.
Turkeys are highly vocal, and ‘social tension’
within the group can be monitored by the birds’
sounds. A high-pitched trill indicates the birds
are becoming aggressive which can develop into
intense sparring where opponents leap at each
other with their claws and try to peck or grasp
each other’s head. Aggression increases in frequency and intensity as the birds mature. Similar
behavior can be addressed towards any person
entering the house.
Unlike with chicken, where you can sit down to observe, you need to
learn how to perform a fast and quiet inspection while walking through
a turkey house. Avoid long stops, move with a steady speed, pick
up on any irregular behavior: dull, passive, lame birds, watery eyes,
swollen sinuses, labored respiration, sneezing and coughing, signs
of pecking and cannibalism, and watch out for any possible sexing
errors in the flock.
Wild Meleagris gallopavo in flight. In nature they can fly
short distances.
22
Turke y S i gnal s
Turkey curiosity
What makes turkeys very different from chickens is
the attitude to their environment. Turkeys have a
never-ending curiosity. They move around, investigating every square centimeter of the house and
equipment. The whole flock will be interested in
you! They’ll follow you all the time, surrounding you
as soon as you stop, watch you, peck your clothes
and boots. You must be very careful not to leave
anything behind which could be easily swallowed by
the birds: threads from the straw bales, wire, plastic,
syringe needles etc. Such objects will end up in the
turkey’s gut and often cause obstruction or damage
to the internal organs, leading to mortality. Another
area of risk are easily accessible electric wires. These
will certainly be pecked down to the metal, creating
the risk of short circuiting and a resultant fire.
As soon as you enter the house, the turkeys stretch their neck and look in
your direction. Turkeys will immediately come towards you and start pecking
at your boots and arms.
If there is anything to tear apart, turkeys will do just
that, so be careful.
At the slaughterhouse, you will unfortunately find all sorts of alien materials in
the turkey’s stomach.
Plastic wires can get wrapped up around their toes
and damage the feet. This bird will not survive.
Unlike chickens, which normally stop reacting to human presence in the
house after a few days, turkeys always run towards and follow the farmer, displaying a keen interest in everything (s)he does.
Plastic wires can get stuck in the throat and stomach
and kill them.
2. Th e t u r k e y
23
Eating behavior
Turkeys are opportunistic foragers. In nature they
spend a large part of the day scratching in litter,
chasing bugs and milling for seeds. The feeding
behavior of commercial flocks depends on the
lighting program. Turkeys have a clear sense of
day length and can anticipate when the day ends
and will alter their feeding behavior accordingly.
Turkeys have distinct meal times whereas broiler
chicken tend to snack frequently.
Walking behavior
Roosting wild turkeys.
Wild turkeys generally move 1-3 km (0.5-2 mi) per
day. The annual home range of wild turkeys varies from 1-1.5 km2 (½ mi2). This habit is intrinsic
for farm turkeys, too. They actively move around
through the house all the time. This behavior must
be considered: turkeys require a lot of free space
for migrating, so feeding lines should be lifted high
enough to allow for the birds walking under them.
Have as few obstacles as possible in the house
(feeding/drinking lines). Unlike broilers, they easily
find the feed and water within a larger area, once
they have learned where they are located.
Roosting behavior
Roosting on the feed line, despite the perch guard.
Wild turkeys roost in trees. In this way they avoid
ground predators. Poults begin roosting from
about 14-28 days old. They behave similarly in the
houses, climbing up the straw bales or on top of
feeding and drinking lines, thus creating a threat
of breakage, feed spillage or flooding the floor.
Strutting
Maturing toms spend a considerable proportion of their time displaying their beauty (strutting). This involves fanning the tail feathers,
drooping the wings and erecting all body feathers, including the ‘beard’. The skin of the head, neck and caruncles becomes bright blue
and red, the snood elongates, and the birds ‘snick’ at regular intervals, followed by a rapid vibration of their tail feathers. Throughout,
the birds strut slowly about, with the neck arched backward, their breasts thrusted forward and emitting the characteristic ‘gobbling’
call. Male poults will display this behavior from the first week.
24
Dust bathing, sunning and preening
Turkeys dust bathe, sun and preen from a young
age, about 2-4 days old. Dust bathing is usually a
flock activity. A dust bath keeps feathers in good
condition. Turkeys flap in the litter to spread dust
over their entire body. Sunning and preening often
follow a dust bath.
Sunning birds recline on one side and extend the
upward wing and leg to expose a large surface
area to direct sunlight. Birds sun for several reasons: to obtain heat as a way of regulating their
body temperature, maintain feather health, dislodge feather parasites and for relaxation.
Preening is a common bird behavior to keep
feathers in good shape. Birds preen to remove
dust, dirt and parasites from their feathers. They
also align each feather in the optimum position.
Active periods are alternated with resting periods up to
about 4 weeks of age. They often lie down in groups,
which doesn’t necessarily mean they are feeling cold.
Dust bathing creates ditches in the litter.
All turkeys are gathered under the beam of sunlight in the middle of the house.
Birds preening, using an oily substance from the preen gland at the base of
the tail.
2. Th e t u r k e y
25
Handling turkeys
There are occasions during the growing turkey’s
life when it may have to be caught and handled.
The first rule is ‘Do not chase turkeys around the
house’. They should be penned up within the
house as a group and then a small pen next to
the dividing partition erected. Turkeys should then
be driven in small groups of 20-50 depending on
the bird size into the small pen. After handling for
whatever purpose, they should then be put into
the other part of the house. The operation works
more smoothly if one person catches and passes
the turkey to another.
Due to the heavy weight turkeys reach by maturity their legs and wings can be easily damaged.
Therefore, turkeys should never be grabbed or
picked up by someone until they have been fully
trained.
To pick up a heavier weighing turkey stand beside
it, reach over the back and hold on to the base of
the opposite wing. With the other hand feel under
the turkey to find the bottom of the legs. If both
legs can be held by one hand, do so. Otherwise
grasp the leg nearest to you before lifting the bird
up. While keeping a solid grip on both body parts,
gently lift the bird. If you have never handled
an adult turkey, do not attempt to do so alone
and have someone with training and experience
demonstrate this to you. The turkey can panic and
easily injure itself or the handler.
Very young birds can be picked up with the help of these
simple pliers.
A metal hook is a good tool to select turkeys in a flock without
disturbing the others too much.
26
You don’t really have to drive turkeys, just making some
noise with a piece of plastic will make them walk.
Turke y S i gnal s
Bird handling procedures
Correct
Incorrect
A very small turkey up to
3 kg/6 lb can be picked up on
two wings with one hand.
A small turkey up to 5 kg/10 lb
can best be picked up by two
legs.
DO NOT pick up a turkey on
one leg.
DO NOT pick up a mediumheavy turkey on one wing.
Medium-heavy turkeys (up to
10 kg/20 lb) can be picked up
by the wings, close to their body.
Hold a heavy turkey (> 10 kg/
20 lb) to the ground: grab the
upper arm close to their body.
DO NOT pick up a turkey at
its wing tips.
DO NOT pick up a heavy turkey by both wings (not even
when held close to its body).
Diagonal transport grip (heavy
turkeys). Hold the left wing at
the upper arm and the right leg
above the ankle joint.
Three point transport grip
(medium-heavy turkeys). Hold the
wing at the upper arm close to
their body with both legs bent.
DO NOT carry a turkey by
both legs and a wing tip.
DO NOT carry a turkey by one
leg and a wing tip.
2. Th e t u r k e y
27
Stampeding (piling up)
The result of piling up. You can immediately have tens or hundreds of dead
turkeys. This usually happens in the corners with no escape for the animals
underneath.
Turkeys that are suddenly frightened at night can
fly violently against walls causing damage to their
legs, wings, etc. They may pile up into a corner
which can cause injury or suffocation. Birds can
be startled by animals, strange noises, or sudden
bright lights. Foxes, dogs, ferrets or raccoons can
cause considerably more damage due to piling up
than the actual number of birds they catch and
kill. The farm’s perimeter should be fenced as an
integral part of a complete biosecurity program.
Higher stocking density creates more risk of piling
up and higher losses. Spray vaccination or individual treatments can be a reason for piling up, so
during these procedures always assign one person
to observe the situation and flock behavior. A
dim night-light is usually provided to prevent the
birds piling up. It can be a separate line of blue/
green light or the main lighting system used on
a very low intensity (3-5 lux/0.3-0.5 fc). Make sure
your light bulbs allow such a low intensity without
flickering, or it may cause more restlessness and
aggression in the birds. Another good practice is
to place a radio inside the house. This will condition them to be less startled by sudden, strange
noises.
Dimmed main light (5 lux/0.5 fc) seems to be very dark, but in practice it is
light enough to prevent piling up.
A large lump of ice falling from the roof in the night can
pose a serious threat of piling up.
28
A measure against piling up and aggressive pecking is the use of blue light in
the house.
A fox on the farm area next to a turkey house.
Turke y S i gnal s
Commercial production systems
Worldwide there are several systems for turkey
production. Basically, sexes are raised separately;
differences in growth rate and basic needs are
too different to manage both simultaneously in a
mixed flock. In North America a farm usually only
has one sex present, in Europe the two sexes are
commonly kept within one house but divided by a
separation. In this case hens are marketed earlier
(16 weeks of age) which allows the toms additional space thereafter until they are marketed at
approximately 20 weeks of age.
The choice of the production system depends on:
• Turkey breed, final body weight, slaughter age
• Cost of investment and availability of land
• Market demands and capacity, amount of meat
to be produced per year
• Production/slaughter planning and meat quality (fresh or frozen)
From a biosecurity point of view it is better to
have smaller farms running all-in, all-out programs, while on the other hand, a big multi-age
farm with a 13 weeks cycle is probably more economical for producers.
In Western Europe most farmers are integrated with an average turkey house size of 1,600
to 2,400 m2 (1,900 to 2,900 yd2) and a farm size
between 4,800 and 9,600 m2 (5,700 to 11,500 yd2).
Mainly heavy breeds are grown, though heavy-medium breeds are not uncommon in France and
Spain. Most farms are all-in, all-out, and although
some farms do have dedicated rearing houses,
they usually start and finish all the turkeys in one
house. The choice in number of farms and cycle
depends on the required meat production and the
required cycles of fresh meat supply. Small companies have the tendency to go for shorter cycles,
bigger ones prefer longer cycles. It is all about
the balance between productivity, investment and
land availability. If land with facilities (water, gas,
electricity, roads) and investment is not an issue,
the focus shifts to biosecurity and long cycles.
The rearing stretches over the first 4-5 weeks.
The fattening periods generally used in heavy
strains:
Toms: 19-22 weeks approx. 19.0 -22.5 kg (42-50 lb)
Hens: 15-17 weeks approx. 9.5 -11.5 kg (21-25 lb)
17-week cycle
Week
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Rearing
Toms
Slaughter
13-week cycle
Week
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Rearing
Hens
Toms 1/2
Slaughter
8-week cycle
Week
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Rearing
Hens/toms 1/2
Hens/toms 3/4
Slaughter
2. Th e t u r k e y
29
Stocking density
A higher stocking density means that you can
spread the costs of the facilities over more kilograms of product. In a cold climate, a higher
stocking density also helps to reduce your heating
costs per bird.
However, it also places more demands on your
ventilation system and litter management.
In hot countries the climate is very clearly the
main limiting factor: the birds can suffer heat
stress which can lead to a large decrease in growth
efficiency and animal welfare issues.
Besides practical limits in most countries there
are also legal limits. This legislation is based on
minimum requirements per bird, with the goal of
maintaining animal welfare. Permitted stocking
densities for turkeys reared indoors vary according
to geographical area and animal welfare schemes.
Overstocking
Some systems (e.g. 13 weeks) make it possible
to place more birds per m2 at a day old (up to 19
poults), since the older, larger birds are moved to
another location at an early age (4-5 weeks). This
is often 50% of the flock (either hens or toms). In
this way you make optimal use of the floor space.
But if the remaining flock is kept in the brooding
houses at such high stocking densities for longer
than 6-7 weeks, they will exhibit welfare problems.
It causes direct stress to the turkeys, leading to
increased pecking and skin scratches, overall
immunosuppression and increased risk of secondary infections. It also leads to lower uniformity
and less overall growth, as well as problems due
to wet litter, such as footpad dermatitis and hip
scratches. The issue of restricting available space
is compounded by the natural social behavior of
turkeys. Turkeys want to feed, drink, dust-bathe,
etc. simultaneously. In order to avoid frustration,
resources and space must be readily available.
Average parameters of stocking density and live weight per m2 (ft2) at slaughter age
Age (weeks)
Hens/m2 (Hens/ft2)
Toms/m2 (Toms/ft2)
0-6
11.0 (1.02)
11.0 (1.02)
7-12
5.5 (0.51)
4.0-4.5 (0.37-0.42)
13-16
5.0 (0.46)
3.0-3.5 (0.28-0.33)
17+
4.5 (0.42)
2.5-3.0 (0.23-0.28)
Maximum kg/m2 (lb/ft2) at slaughter age
56 (11.5)
64 (13.1)
At the end of the cycle it becomes very crowded in the
house. When turkeys panic, this can potentially lead to
more injuries or death.
30
Hens at slaughter age.
Turke y S i gnal s
Alternative systems
Most of the turkeys are kept indoors at a high
stocking density, but for some markets alternative
systems have been developed.
Extensive indoor
Extensive indoor rearing uses lower stocking densities and environmental enrichment is usually
provided. For example, in the UK the RSPCA’s
Freedom Food standards for turkeys stipulate
higher light levels, a maximum stocking density of
25 kg/m2 (5 lb/ft2) and the provision of enrichment
such as straw bales, perches, hanging lengths of
rope and other objects for pecking. Enrichment
has been demonstrated to reduce harmful pecking
of other members of the flock.
Free range
Free-range turkeys are usually slower-growing
breeds, which are less susceptible to heart problems and lameness associated with fast-growing
breeds. In the EU the maximum stocking density
inside the shed is 25 kg/m2 (5 lb/ft2) and in addition at least 4 m2 (43 ft2) per bird is required for
an outdoor range. In some countries, free-range
turkeys are common for reasons of meat taste and
texture, rather than welfare. Meat texture is influenced by exercise (muscle development), and rate
of growth.
Fully covered yards or pole houses are common,
using natural ventilation. The upper parts of walls
are open. Solid lower parts to the walls reduce
drafts at bird height and screens can cover the
openings in bad weather. Insulation is minimal,
except sometimes over a roosting area for increased protection at night, so it is only suitable
in mild climates and often seasonal production.
Stocking density is low and flocks generally small,
e.g. 400–600 birds.
Organic
Organically reared turkeys are usually slower-growing breeds and must have access to an
outdoor run. In the EU, the maximum flock size
is 2,500 birds per shed. The maximum stocking
density inside the shed is 21 kg/m2 (4 lb/ft2) and
in addition, there must be an area of at least
10 m2 (108 ft2) per bird on the outdoor range. Beak
trimming is discouraged in organic systems. After
8 weeks the doors always remain open. The minimum slaughter age is 100 days for hens and 140
days for toms.
Free range turkeys in Austria.
Covered yards can be covered with curtain screens in
case of rain or cold.
2. Th e t u r k e y
Free range turkey house with distraction materials (bags of hay) and in front, a
hospital area for weaker turkeys. The upper side of the wall allows daylight to
enter.
31
CHAPTER 3
Hatchery and day-old poults
Hatcheries fall into three main types: as part of an integrated company, belonging to an independent
company with breeding farms and a hatchery to sell poults on the open market, or the hatchery
purchases hatching eggs (often from abroad) and sells the poults. No matter the source of poults, good
poult quality is the basis for good performance in brooding and grow-out. Breeder management (e.g.
flock health, nutrition, egg management) and hatchery (e.g. incubation profiles, poult treatment and
delivery) play an important role in supplying good quality day-old turkey poults.
Healthy breeders = safe and vital poults
Before delivery of hatching eggs make sure the supplier guarantees
that the flocks from which the eggs originate are free from:
Mycoplasma meleagridis, synoviae, gallisepticum and iowae. These
can be vertically transmitted via infected parent stock to the hatching
eggs. It is the responsibility of the primary breeding company and
multiplier company to supply clean poults and the responsibility of the
commercial breeder to keep them clean.
32
Floor eggs and dirty eggs harbor large numbers of
bacteria on the shell surface. These can penetrate
into the egg leading to massive proliferation and
finally to explosion of the infected egg. Pathogens
kill the embryo usually after a couple of days of
incubation: early embryonic mortality. Washing
and disinfecting dirty eggs reduces the risk of
explosion. Dirty eggs should not be incubated. In
case you still decide to do so, do this in separate
setters, so that poults from dirty eggs do not contaminate the ones from clean eggs. However, these
poults are often still mixed with a batch of poults
from prime hatching eggs, which increases the risk
of losses due to possible harmful pathogens.
Turke y S i gnal s
Egg transport and storage
Storage conditions
The temperature during egg transportation should
never exceed the ‘physiological zero’ of the embryo
(20°C/68°F). Above this temperature embryos start
developing and, if followed by a temperature drop,
this can lead to early embryonic mortality. For the
embryos that survive and hatch, the consequence
can be a poor vitality and low performance. The
optimal egg transportation temperature is 15-17°C
(59-63°F). Always use temperature loggers and
check them at arrival.
Storage is done on the breeder farm as well as
in the hatchery. Egg storage leads to increased
embryonic mortality both at the beginning and
the end of incubation and to a reduced growth
rate of the embryo leading to a delayed hatch.
There are several known ways how to maintain the
hatchability of eggs after long storage times: turning them every 24 hours, covering with plastic to
maintain high CO2 levels, pre-storage incubation
for 3-6 hours (after achieving 32-35°C/90-95°F egg
shell temperature), and humidity control.
Storage period Temperature Relative humidity Egg orientation
(days)
(°C/°F)
(%*)
0-3
18-21 / 64-70
75 - 85
Blunt end up
4-7
15-17 / 59-63
75 - 85
Blunt end up
8-10
12-14 / 54-57
80 - 85
Blunt end up
> 10
12-14 / 54-57
80 - 85
Small end up
or alternatively
turning the eggs
every 24 hours
* Recommended range for eggs stored on paper trays is 50 - 75%: the risk for dehydration is much smaller and the occurrence of floppy trays due to too high relative humidity
should be avoided.
An unacceptable temperature fluctuation up to 33°C (91°F). The forecast for
these eggs’ hatchability is poor. You can’t store these eggs – set them immediately to minimize damage. Notify the supplier. The cause of the temperature
fluctuation should be investigated to reduce the risk of a reoccurrence.
Small temperature logger with an integrated printer. This one does not register
humidity, so you won’t obtain complete information.
Check the temperature and relative humidity in the storage room regularly. Make sure that while the eggs are
kept in a humid environment, they don’t get wet! This is
an ideal environment for fungal and bacterial colonies
which can have a strong influence on embryonic quality
and development.
3 . H at c h e r y a n d d a y - o ld po u l ts
Electronic temperature/relative humidity logger with a PC reader.
33
Setting
All or some eggs on a tray are printed or otherwise identified with the day of
production, to make sure the eggs are set in the order in which they were laid.
The incubator manufacturer’s or egg suppliers’
recommended temperature and relative humidity
should be followed, but needs to be fine-tuned
per hatchery. The correct settings can be achieved
by measuring the embryo or eggshell temperature
at different stages of incubation and adjusting
incubation regimes based on the actual results. In
the past, incubation regimes were often based on
set air temperature. Infertile eggs and dead embryos will result in egg shell temperatures lower
than that of the other eggs and lower than the
profile temperature. Overheated/underdeveloped
poults have compromised skeletal (leg problems),
cardio-vascular, gastro-intestinal and immune
systems, and are at a higher risk of disease and
mortality at a later stage of growth due to sudden
death syndrome, ascites or ‘round heart’ disease,
immunosuppression and secondary infections.
Regularly calibrate your T/RH sensors, check the
fan speed, belts and air speed.
Manual egg shell temperature measurement can be performed by an IR thermometer on the egg equator.
After eggs arrive at the hatchery make a thorough selection. Setting only high-grade eggs will reduce the chance
of hatching poor quality poults.
Example of critically overheated batch of eggs
Automatic egg shell temperature sensor.
34
Top
Middle
Bottom
Egg shell
temp. (°F)
102.9
102.6
101.4
102.5
101.9
100.6
101.4
100.0
100.4
100.2
104.0
104.0
104.1
102.3
103.5
103.1
101.7
102.2
101.2
101.6
102.4
103.7
104.1
103.3
103.4
101.3
103.1
102.0
102.0
101.8
Average
temp. (°F)
101.4
102.9
102.8
Always measure eggshell temperature in 3 zones: bottom,
middle and top of the setter. Often the Fahrenheit temperature scale is used for temperature measurements.
Turke y S i gnal s
Candling and breakout
Typical items in a hatching report:
Egg candling at 13-15th day of incubation allows
for evaluation of the clear (infertile) and dead
embryos and to thereby forecast the hatchability
rate. For a good hatch it is desirable to have at
least 92% of eggs fertile as an average per batch.
Remove all clear and dead-in-shell eggs from the
trays. Otherwise, these eggs will create cold spots,
which, when in contact with living embryos, slow
down their development and thus ‘widen’ the
hatch window. It will eventually increase the number of weak dehydrated poults at hatch. Candling
eggs does not distinguish, ‘true’ and ‘false’ infertiles (early embryonic mortality). Breaking eggs at
candling or after the hatch to check the contents
helps to classify the stages and possible reasons
of embryonic mortality, and to react accordingly:
make adjustments to the breeders’ health status,
nutrition management, egg collections, transportation and storage regimes and general hygiene or
incubation regimes.
Flock age (weeks)
Fertility %
Hatch %
Hatch of fertiles %
Infertile %
Early mortality %
Middle mortality %
Late mortality %
Pipped live/dead %
Cull chicks %
Cracks %
Cull eggs %
Upside down %
Exploded %
Clear eggs with no embryonic development (true infertiles)
The obvious first place to look is at the
fertility of the toms, but there are many other
possible factors. Improper artificial insemination techniques can also seriously hurt your
flock’s fertility.
Manual candling at 13 days. The eggs that are completely clear are not fertilized or there was early embryonic death.
Dead embryos at early stages
Dead embryos at middle/late stages
Early stage death often signals an issue after
laying during transportation. Improper or
long storage, and inappropriate incubation
conditions are often the cause. Nevertheless,
watch for nutritional deficiencies and sources
of contamination in the breeder house.
Mid- late stage embryo death can often be
rooted in nutritional deficiencies: either a vitamin or trace mineral deficiency or a high level
of a mycotoxin. On dead-in-shell examination, a high level of deformity is usually seen.
Infertile
Not all of your infertile eggs are unfertilized. Overlong or improper storage, or damage during collection or transportation may have
caused embryonic death at a stage before it is visible to the eye. If there has been any development, it will show up as a milky appearance on the yolk. These types of losses will be marked as infertiles and you may spend a long time chasing down a problem that
doesn’t exist. Collect your eggs frequently and always be proactive with storage conditions.
A set of eggs with early - mid - late embryonic mortality.
3 . H at c h e r y a n d d a y - o ld po u l ts
35
Hatching
LOOK-THINK-ACT
The hatch window is a time frame from the onset
of hatching until its conclusion. In turkeys, the
hatch window should be less than 36 hours. A narrow hatch window, less than 30 hours, indicates
a strong, uniform hatch. A wide hatch window,
greater than 40 hours, indicates that the poults
are hatching unevenly and will be susceptible to
problems such as dehydration of the early hatched
poults. By monitoring your hatch window on a
regular basis, you can determine when your hatch
window has been positively or negatively affected.
You can also register the start of massive poults
pipping by the rapid rise of CO2 and RH% in the
hatcher.
What does the fluff on the floor tell you?
What influences hatch window?
•
•
•
•
•
A lot of fluff on the bottom of the hatchers at 27 days. Lots of fluff in
the hatchers is a sign of well-developed good quality poults, because
it indicates good climate control in the hatcher.
•
Parent flock age. Avoid setting eggs from
young and old breeders together (different
egg sizes cause variation in incubation time).
Parent flock health: hens suffering from
health issues can produce eggs with a more
advanced germ cell.
Uneven temperatures on the breeder farm:
inside the egg rooms or between egg houses if the eggs are set from various breeder
flocks.
Uneven egg temperatures in the hatchery. If
the pre-warming temperature is not uniform,
check your heating equipment, ventilation
and pre-warming time in the setter. Start the
pre-warming earlier.
Incubators with uneven cabin temperatures,
varying humidity or airflow variation.
Too many infertile eggs, creating cold spots
around fertile eggs, slowing down their
embryos’ development.
Total hatch (%)
36-hour hatch window
100
80
60
40
20
0
36
30
24
18
12
6
0
Hours to pull
The standard is to have less than 1% hatched 36 hours prior to pull time. The
peak of the hatch will optimally occur approximately 11 to 14 hours before pull
time.
36
Employees performing a hatch window count.
Turke y S i gnal s
Hatched poults harvesting
Separating the normal viable poults from hatch
debris requires training. Determining whether a
poult should be harvested or euthanized requires
understanding of the hatching and maturation
process. When handling of individual poults is
necessary, it must be done carefully to avoid injury. The poult should be picked up with the head
towards the handler’s wrist. The fullness of the
abdomen can be felt between the forefinger and
the thumb. The feet and navel can be examined by
turning the poult upward. Disposal of the hatchery debris and unfit poults must result in a quick,
humane death with minimal chance of any live
poults being left in the debris. High speed grinding (maceration) results in immediate death for
unhatched embryos or non-viable poults. Another
acceptable method of euthanasia is carbon dioxide gas. Many countries have legislation that
requests euthanasia through the use of CO2.
Poult yield
Poult yield is the poult weight expressed as a percentage of the egg weight before incubation.
Poult yield is a useful indicator of whether:
• Poults are recently hatched (green or fresh) or
old and dehydrated.
• The hatch timing is advanced or delayed.
Typically, poult yield is between 66 – 68%. Low
yields (< 65%) indicate the hatch time is advanced
whereas high yields (> 70%) indicate that hatch
time is delayed.
If hatch timing is incorrect, this may be caused by
inappropriate setting times or because of incorrect
incubation conditions. Low yields indicate that the
poults have been hatched for a long time before
pull time and have become dehydrated. High
yields indicate that the poults have only recently
hatched and are possibly too green to go to the
farm immediately.
If very young or old poults are delivered to the
brooder farm this can result in early poult mortality problems and an increased incidence of flipovers!
Weighing empty egg tray.
Weighing full egg tray.
Weighing empty poult box.
Weighing full poult box from
the same eggs.
1. Calculate the average poult weight (PW): PW = (Full box – empty
box) ÷ number of poults
2. Calculate the poult yield (PY%) = (Ave. poult weight (PW) ÷ Ave.
egg weight (FEW)) x 100
3. Normally a sample of 5 trays per flock at each hatch will give a
good indication of the poult yield.
If you are seeing weak poults, which seem to struggle to maintain a proper
standing posture then watch out for high hatcher temperatures and poor ventilation, excessive fumigation and possible sources of contamination.
3 . H at c h e r y a n d d a y - o ld po u l ts
37
Poult quality
Grading may be done as part of the poult harvest
operation. At this stage the second quality poults
are removed and humanely discarded. Poults are
usually rejected for one of three main reasons:
1. improperly healed navel
2. small
3. spraddled/splayed legs
The most common and important quality problem
is an unhealed navel. This can be up to 9-10% of
all poults hatched. Even with good hatchability,
1-2% of all poults will be affected.
A fully developed poult should possess a completely healed navel. From the earliest stages in
development the yolk sac grows. It develops a
blood system of its own about 50 hours after the
start of incubation to transport nutrients from
the yolk to the developing embryo. Towards the
38
end of incubation, on the 26th day, the remains
of the yolk sac are drawn into the body cavity by a
combination of abdominal muscles and leg movements and after this the navel should close, sealing the yolk inside. There is enough yolk material
remaining to sustain the poult for up to 48 hours
after hatching. The most likely causes for unhealed
navels are older eggs and improper incubator
conditions (overheating). A navel infection (omphalitis) occurs when the navel doesn’t close properly after hatching. It can also be caused by poor
sanitation in the incubator or hatchery, chilling, or
overheating. Mortality may be high in the first 4
or 5 days of life. It cannot be treated. Report this
problem to your poult suppliers.
Ectopic (exposed) viscera. Incubator temperature too high. Check embryo/egg shell
temperature during incubation period and
confirm the accuracy of your thermometer.
Premature hatching; bloody navels. The
temperature is too high in the incubators
or hatchers. Check shell temperatures and
thermometer accuracy.
Navel infection. The abdomen becomes
enlarged, soft and mushy. An infected
navel is surrounded by a bluish black area
and spreads a putrid odor.
Navel strings. The umbilical blood vessel
does not dry down and fall off normally.
High humidity in the hatcher. Review
hatcher humidity profiles.
Navel scabs. High hatcher temperature.
Poult develops quickly and does not fully
absorb the yolk sac into the body which
forms a scab. Check temperature profiles
and the accuracy of the thermometer.
Hemorrhage. Red skin, bleeding in chorioallantois. Caused by nutritional deficiencies
(often vitamin K or E), mold and bacterial
contamination, high incubator or hatcher
temperatures, and heredity factors. Check
incubator or hatcher temperature.
Turke y S i gnal s
Poults hatch wet, they shouldn’t hatch sticky; this poult
is covered in albumen. Monitor the storage and fumigation practices. This could also be a sign of inadequate
incubation temperature, ventilation and turning, as well as
excessive incubation humidity.
Many pips stuck to shells. Excessive residual albumen
due to high relative humidity and/or low temperature incubation. Low humidity during hatching. Monitor moisture
loss at transfer and embryo temperature during incubation.
Poults with shell fragments stuck to their down feathers
are a signal that moisture loss was too great in the postlay period. Often this comes down to incubation; low
humidity or insufficient egg turning. It is recommended
that eggs be turned a minimum of 8 times daily during
incubation.
The normal position of an embryo within an egg is for the
developing bird’s head directed towards the large end
of egg, with the beak tucked to the right and under the
right wing. In this position the beak will point towards the
air cell and the feet will curl in towards the head. A poult
that develops in a different position is likely to experience
some problems during the hatching process.
This poult did not pip, despite being full-term it could not
crack the shell. Note the large yolk sac remaining, and
possibly some residual albumen. This bird did not finish developing. Perhaps the egg was stored too long or
was chilled at some point during transfer from the turkey
house to the incubator.
These poults managed to crack the shell but could not
escape. It is possible that rough handling, poor temperature control preincubation or long storage may have
played a role in this, as might have improper orientation
during incubation, improper turning, temperatures and
humidity. Do not open the hatcher door during peak
hatching as this will cause a sharp drop in relative humidity and cause the membrane to dry out, trapping the
hatching poult.
3 . H at c h e r y a n d d a y - o ld po u l ts
39
Abnormalities
Some of the more dramatic hatch defects, such as blindness (left photo),
additional limbs (right photo), additional or absent toes can be caused by
many factors. Rough transportation, poor nutritional factors, improper incubation temperatures, ventilation and improper egg orientation can all play a role.
This poult is poorly developed: note the
short beak and facial abnormalities. Firstly,
look for nutritional deficiencies on the
breeder farm (niacin), or any hereditary
abnormalities. Otherwise look at incubation
temperatures.
Genetics will only be the cause of a very small
number of abnormalities and this would not
change from hatch to hatch. In the case of
deformed toes, the cause can sometimes be
genetic, but they may also be caused by a vitamin
B deficiency in the breeder flock or high incubation temperatures. In case of a high incidence
of abnormalities, inform the breeders farm so
they can check the nutrition of the parent stock.
Occasional abnormalities are not a cause for concern. Further investigation is appropriate only if a
single malformation occurs at levels over 0.5% of
the eggs set.
This poult’s brain is exposed (acrania). This
is likely due to an error in early incubation.
Watch out for excessively high temperatures or low oxygen levels during the first
three days of incubation.
This poult has a beak deformation and is
missing an eye. This is likely an incubation
problem; watch out for high incubation
temperatures and low oxygen levels during
the first week.
Red beaks and hocks
When poults struggle during the hatch you will often see red
spots on the hocks or on the top of the beak. This is caused
by damage to the soft tissues against the hard eggshell. Difficulties during hatch could be caused by many factors either
on the part of the incubator or the breeder. On the hatchery
side, monitor your temperatures and humidity carefully. Red
beaks can also happen post-hatching when the poults stick
their heads through the holes in the box or tray and thus damage the top of their beak on any rough edges.
Red beak.
40
Red hocks.
Turke y S i gnal s
Sexing
Sexing is necessary so that toms and hens can be
raised separately and the management and nutritional needs of the different sexes can be better
met. Injury prevention and accuracy are the main
focuses in the sexing procedure. For good sexing
results insure that sexers have a:
• comfortable sitting position
• proper light
• correct hand technique
Sexing errors are costly: the later the error is
caught the more the producer pays in a loss of
production and efficiency, and the more risk there
is moving heavy birds between turkey houses.
A comfortable position and good light are essential for
good sexing results.
Sexing requires a subtle hand technique.
♂
♀
It is very difficult to see the differences in sex. Only very well trained and experienced personnel will be able to perform this
task (often Asian people are experts). It is good practice to periodically check the accuracy of individual sexers.
3 . H at c h e r y a n d d a y - o ld po u l ts
41
Beak treatment
Beak treatment is used to prevent feather damage
and potential injuries from birds pecking each
other. From an animal welfare point of view, this
practice is debatable. In some countries, such as
the USA, turkeys routinely have their beaks trimmed
as poults in the hatchery. In the UK, only 10% of
turkeys are trimmed. A considerable amount of
research has been done into finding ways of reducing feather pecking and cannibalism. It is likely that
the practice of beak treatment will be banned within
a few years in Europe. Beak treatment can be performed at day old or up to 3-5 days of age.
Infrared beak treatment
Infrared devices offer a humane solution. The burst of IR light damages the growth cells. Within two weeks the dead tissue flakes away
painlessly and the poult can keep using its beak normally. The upper beak remains somewhat shorter than the lower and will not have the
sharp edges that can injure other birds.
IR-machine. The goal is to remove the least
amount of beak required to prevent pecking.
Just after treatment you see a small brown line on the upper beak; this area will slowly
turn brown and flake off.
Hot blade beak treatment
The hot blade method targets the germinal tissue of the upper beak of the day-old poult, heating it to damage the growth areas and
reduce the overall growth of the upper beak. There is little blood loss and little impact on poult behavior. Vitamin K can be used to stimulate blood clotting and reduce the number of bleeders. In many places this has been the standard for a number of years.
A hot blade debeaking machine.
A beak treated with hot blade. The tip is burned off and leaves a wound.
Beak clipping
Beak clipping by hand is very painful for young poults and creates bleeding wounds open to bacterial contamination and increased
mortality in the first week of life. In addition, you can expect a reduction in feed consumption for a few days after this procedure.
All in all, not a good start and the practice is not (commonly) used anymore in the turkey industry.
Manual debeaking is the worst of all choices. Don’t do it: it is cruel and not worth the
loss of production.
Manually trimmed beaks often overgrow.
The attempt to protect your bird backfires
and the beak remains a lethal weapon.
Claw treatment
Especially in North America, claw treatment is
applied in commercial hens destined for the whole
body market, in order to avoid scratches and bruises that would lead to infections, mortality and
would downgrade the carcass. In breeders, when
applied automatic nests, usually the dew-claw is
removed, since this backward sticking toe often gets
caught in the nest mechanism.
Microwave claw treatment penetrates the tissue
around the nail bed, disrupting the growth of claws
and causing the nail to slough off after a few weeks.
A short burst of microwave energy is directed at
each claw. It is bloodless without an open wound,
so less risk of infections.
In the past this procedure was performed with surgical scissors or a hot blade, but nowadays generally microwave claw treatment is applied. It is considered a more humane method of treatment. Within
two weeks, as the cells fail to reproduce, claw tissue
darkens, shrinks and falls away. In most countries
this treatment is not common practice.
Microwave claw treatment.
A claw 24 hours after treatment. Treated tissue turns
white and will slough off 2 to 3 weeks after treatment.
A treated claw 39 days later, the nails have fallen off.
In this hatchery, the three forward facing digits are processed using microwave equipment, while the back toe
(dew-claw) is treated with a hand tool.
A mechanically clipped dew-claw.
3 . H at c h e r y a n d d a y - o ld po u l ts
43
Snood treatment
44
Snood treatment is NOT standard procedure.
However, some farmers remove the snood or dewbill to prevent head injuries from pecking and fighting. In North America, de-snooding is performed
in about 15% of the commercial toms. In breeder
flocks a large part of the toms are de-snooded. The
snood treatment should be done at an early age
by trained personnel. At one day old, the snood
can be removed by thumbnail, finger pressure or
with special forceps.
Intact snood.
Desnooded poult.
Manual clipping.
Males with pecked snoods.
Male with a fully grown snood at slaughter age.
Desnooded male at slaughter age.
Turke y S i gnal s
Poult delivery
Different types of poult crate lining are available
to prevent spraddled legs and other discomfort
for poults between hatch and placement in the
turkey house. The poults need some grip during
storage and transport. There are various materials
that could be used. Most common are one-way
cardboard boxes. This is due to hygiene factors.
The risk of re-usable materials is that it can spread
diseases like AI if disinfection is not performed
correctly. Besides, the logistics are easier with dispensable materials.
LOOK-THINK-ACT
What is wrong with these transport crates?
These crates are too low, leading to damaged poults during palleting
and potential overheating during transportation and storage.
Wood wool in crates.
Corrugated cardboard.
Fine plastic mesh on top of ribbed cardboard.
Poult on a plastic mesh surface.
Rubber corrugated mats are costly, but reusable, easy
to wash and can be thoroughly disinfected. However, if
disinfection is performed incorrectly they will be a source
of infection.
3 . H at c h e r y a n d d a y - o ld po u l ts
45
CHAPTER 4
Biosecurity for profit
The day-old poults should arrive at a clean farm and it should remain that way. The goal of a biosecurity
program is to minimize the risk of bird sickness from outside sources as well as internal contamination.
Biosecurity is often the cheapest and most effective management intervention for achieving better
results, but sticking to all the procedures can be difficult if things are not carefully planned from the
start. No system can be 100% secure. The risks decrease in relation to the amount of money invested.
The more valuable the turkeys on the farm in terms of numbers and types of turkey (pedigree breeding
stock and parent stock being extremely valuable), the more expenditure that can be justified.
To understand the measures taken to ensure biosecurity, you have to understand the risk factors
involved. The bottom line is that you want to
prevent disease transmission before you have a
problem. Ideally this starts long before farm
construction, to reduce the potential future risks.
If there are special circumstances, e.g. indications
of an increased ‘field virus-pressure’ all hygienic
procedures should be intensified.
46
1. Location of the farm: preferably away from
other (poultry) farms and roads so that airborne
germs cannot infect the farm. And away from
ponds and rivers, harboring wild waterfowl.
2. Effective layout: the farm is completely
enclosed within a perimeter fence. The farm
is divided into a clean part where the turkeys
are kept and a dirty part, with access to the
outside world. The dirty route is used by trucks
to unload the feed, or to pick up dead birds,
without coming into close proximity with the
turkey houses.
Turke y S i gnal s
Farm location
feed silo filling pipe
DIRTY ZONE
BUFFER ZONE
CLEAN ZONE
turkey house
buffer zone
access point
parking
external road
public road
Distance is considered the most important factor
for ensuring a good biosecurity. A poultry operation should be located in an area with low poultry
density. Minimal distance between the operation
and high-risk factors is about 5 km (3 mi), these
include other poultry/game bird, pig operations,
slaughterhouses etc. In most situations it is
impossible to change the location of the premises.
However, it is usually feasible to optimize performance and/ or to improve the equipment. With the
ideal situation in mind, it is possible to make the
correct decisions.
All roads and places for loading and deliveries
should be paved. After rainfall no pools of water
should remain on the pavement. It is even advisable to include a paved strip of at least one meter
around the houses to aid in rodent control.
clean zone
access point
dead bird
storage
vehicle
disinfection bath
turkey house
hygienic lock
fence around the
between ‘buffer’-zone operation indicates
and ‘clean’ zone
the ‘buffer’-zone
Example of a farm layout with the various biosecurity zones.
Dead bird storage
The flock should be checked at least twice a day if
they are healthy and up to four times a day in case
of the outbreak of disease, so that dead or ailing
birds can be quickly removed. Dead birds should
be stored in a freezer or a chilled room in such a
way that it can be closed to prevent contamination. The place where the dead birds are picked up
for transport, should be as far as possible from the
houses (in the dirty area).
At the vehicle entrance, a method of disinfecting the vehicle wheels is required.
When using a disinfectant bath, make sure it is well maintained (fresh water and
disinfectant). Spraying the undercarriage and wheels with a hand-sprayer can
be easily performed before allowing the truck to enter the premises.
High risk factors for disease transmission
•
•
•
•
•
•
•
By allowing feed trucks to unload the feed from an external road you prevent them entering the buffer zone of the
farm.
4. B io s e c u r i t y f o r p ro f i t
•
•
•
•
Vertical transmission: eggs or poults from infected breeders
Infected birds within a flock
Multiple ages of the same species reared together or in close
proximity
Newly acquired birds added to an existing flock
Different species of birds reared together or in close quarters
Humans; hands, hair, shoes and clothing can harbor infectious
agents
Wild birds, rodents, flies, darkling beetles, other insects, and
parasites
Contaminated feed, water or air
Contaminated vaccines and medications
Contaminated equipment brought onto the farm (trucks, tractors)
Private poultry/bird keeping in the neighborhood.
47
Farm entrance
48
A chain linked fence around the farm is desirable. At the entrance to the farm there should be
a building containing clean overalls and rubber
boots which should be worn before entering the
farm. Records must be kept of all visitors who
enter the farm, such as name, date, declaration of
being ‘clean’ and healthy, purpose of the visit and
signature of the visitor. Preferably, the location
and time of their last visit to another poultry farm
should be recorded as well.
Most turkey houses have an ‘anteroom’ before
moving into the turkey area. On large commercial
farms, changing boots and coveralls before entering each house in combination with hair nets and
hand sanitizing are measures that should be taken
before entering the birds in a flock. At least three
days downtime between visiting different flocks is
essential for veterinarians, feed consultants and/or
breeder representatives.
The most simple and efficient barrier is to divide
the anteroom into a clean and dirty side separated by a bench. Clean footwear is kept in the
clean side. Staff and visitors entering the house
sit on the bench facing the dirty area and remove
their footwear. They then swing their legs over the
bench to the clean area where they put on clean
footwear. When the visitors leave the house, the
boots are removed and cleaned. This is a simple,
quick method of preventing disease being carried
into the turkeys via footwear which is the most
likely route of entry.
Breeding companies will have their own biosecurity system and code of practice, since breeding
turkeys are much more valuable and any health
risk should be avoided. Usually this will include
showering before entering the bird area. Showers
on farms growing birds for meat are less common,
but highly recommended. Each farm’s biosecurity
should consist of a series of defensive barriers
with the turkeys at the center.
Pump with disinfectant just before you enter the house.
Showers are a way for making sure that employees or
visitors do not take infections into the farm.
A boot dip and hand sanitizer provided at the entrance
to the houses is a last line of defense against any pathogens hitching a ride to your flock. Keep your boots clean
and change the disinfectant regularly. All doors must be
locked when no one is inside the house.
After finishing certain activities (washing drinkers,
removing dead birds) hands must be washed thoroughly,
therefore a sink must be installed in each turkey house.
Turke y S i gnal s
Equipment and materials
Before equipment or other materials are delivered
it should be known where they were produced
and/or stored and who transported them. Every
transporter should supply a written declaration
stating that the truck was cleaned and disinfected
before loading and transportation. Vehicles for
on-farm deliveries of poults and feed should be
disinfected before entering the farm site.
Care should be taken to ensure that equipment
such as vaccination instruments and scales are
not taken inside the house without first being
washed and disinfected. Tools and other equipment should be left permanently in the building
where they are needed. All new equipment should
be cleaned and disinfected before entering the
clean area. Material or equipment not needed on
a daily basis should not be allowed in the buffer
or clean area.
Street shoes should be left in the dirty area. Make sure
there is a correct way to store these shoes temporarily.
Shoes and clothes should always be cleaned as soon as
possible after use. Store them in such a way that recontamination is impossible. You can also use different colors
in different parts of a farm. In this case the dark boots are
used in the buffer zone (farm) and the white boots in the
clean zone (house), while street shoes have been left in
the dirty area.
This litter tiller is moved between houses by a forklift. This
prevents dirty litter being spread over the whole farm, and
the tiller’s wheels from touching the potentially contaminated outside ground.
Simple sanitary lock between the buffer and clean zones. The ‘street’ shoes are left on one side of the threshold
and the farm boots are put on inside the clean area and don’t leave the clean area.
4. B io s e c u r i t y f o r p ro f i t
49
Vermin
Besides people, animals pose an extremely potent
risk to biosecurity. Where you have poultry, you
have vermin; there is feed, places to hide and
a suitable climate for multiplication. Besides
the risk they pose to your biosecurity program,
rodents can also cause direct damage to your
turkey house and equipment! As a minimum,
every operation should have a written program
addressing the methods of control of wild birds,
rodents, flies, lice, mites, fleas and darkling beetles. Records should be kept of procedures and
chemicals used. Sufficient down-time is ideal for
eliminating vermin: bait becomes more attractive
when feed is scarce, there are fewer places for the
vermin to hide, and the risk of birds being inadvertently contaminated with pesticides is small.
A good pest control program has three elements:
Prevention: make the house inaccessible or less
attractive to vermin. Monitoring: look for signs of
vermin such as traces of feeding, droppings, footprints. Eradication: use pesticides to stop them
from multiplying.
Flies
•
•
•
Risk: spread pathogens such as Campylobacter and
Salmonella.
Prevention: fly screens on air inlets and outlets, remove
waste quickly, remove manure from the farm.
Control: long-acting insecticide at point of contact, or an
insect killer lamp (the fluorescent light attracts flies which
are electrocuted by the electric wire grids).
Darkling beetle
•
•
•
Risk: spreads pathogens, damages insulation.
Prevention: use insulation with a solid top layer, smooth
profile on house wall, remove manure from farm.
Control: insecticide during down-time, but a smooth
metal strip or metal sheet against the wall can also be
effective in preventing further spread. Important to use
insecticides on the walls just before taking the birds out
and heating up the house before placing the new flock
(before the house cools down and warms up again).
Rodents
•
•
•
50
Risk: spreading disease organisms such as Salmonella,
damage to infrastructure e.g. short circuiting caused by
gnawing through electricity cables, loss of feed.
Prevention: clean up waste or feed sources around the
turkey house, maintaining a clear-cut buffer zone around
the house, properly closing doors and narrow ventilation
openings.
Control: bait traps, e.g. containing anticoagulants. However, many rats are immune to this.
Turke y S i gnal s
Rodent control
After the turkey houses have been emptied is the
perfect time to aggressively eradicate rodents and
other pests, since these are possible vectors for
diseases.
When there are turkeys in the house, keep your
eyes open for rodent signals and maintain rodent
control:
• Regularly check the bait stations along the turkey house perimeter.
• Keep the bait always fresh, rotate types of
baits used quarterly.
Rodent facts
Prolific:
1 rat produces 118 rats/year
1 mouse produces 50 mice/year
Eats feed:
1 rat eats 9 – 18 kg of feed/year
Spreads disease:
salmonellosis, mycoplasmosis,
colibacillosis, coryza,
pasteurellosis, capilariasis,
ascaridiasis
Damaging:
Constant gnawing damages wires,
insulation, wood structure
Range:
Mice usually within 10 m of feed
source, do not need water source.
Rats travel many kilometers to find
feed; drink 20 ml water/day
Rule of thumb for presence of rats:
• If you only see signs of rats/mice (droppings,
gnawing), there are a few.
• If you see them occasionally at night, there
are more.
• Occasional daytime and numerous night sightings means there are quite a lot.
• Seeing several in the daytime means that you
have a serious issue on your hands!
By spilling feed you don’t only lose money, you also
attract rodents and birds.
If you see rats at daytime, then you really have a problem!
Rats are mainly active during twilight and nighttime.
Signals of rodents or darkling beetles: pieces of insulation
material on the floor.
A mouse in the feed hopper. Mice can carry disease,
but if this mouse was killed using a poison baited trap, it
could pose an extra risk for the turkeys.
4. B io s e c u r i t y f o r p ro f i t
51
Rodent prevention and eradication
Keep an area of at least one meter from the walls clean.
This area hasn’t been cleaned recently and the grass is
too high.
A grass area in between houses is an excellent hiding
place for all kind of animals. Keep vegetation growth next
to houses to a minimum at all times.
Here wires are unprotected. Make sure that electric wires
are in a closed casing that is inaccessible to rodents.
This is safer, easier to clean and prevents rodent damage.
Rat poison can be used in fighting rodents. Make sure
that it’s put in a place where it can’t come into contact
with turkeys or turkey feed. And of course, out of reach
of children.
A bait trap outside a turkey house. Poison is placed inside for rodents to eat.
52
Turke y S i gnal s
Insect control
To achieve the best result in controlling insects,
insecticide must be applied twice during the sanitary period: just before clean-out and after the
final disinfection. The purpose of the first ‘dirty’
eradication is to prevent the escape of the insects
(e.g. darkling beetles) from an empty cold turkey
house (without birds and feed).
Darkling beetles are a known problem insect.
They are pathogen transmitters, damage turkey
house insulation, and eat feed. Between production cycles darkling beetles and their larvae prefer
to hide in their ‘shelters’ (cracks in the floors, wall
insulation etc.). The best time for their effective
eradication therefore is immediately after the
birds are removed to slaughter, when the feed is
removed and the temperature in the house starts
dropping. To increase the efficiency of the insect
eradication, push the litter from the side walls for
1.5-2.0 m (5-7 ft) towards the center of the house
and spray the open floor, the corners and the walls
with an insecticide up to one-meter in height.
Thus, you limit the possibility for the insects to
escape. Rotate the insecticide products you use to
avoid the insects building up resistance and use
boric acid.
Use a pesticide that is suitable for the type and
location of treatment and follow the instructions for its application (procedures, rates). The
combined treatment including adulticide (e.g.
Cyfluthrin) and larvicide (e.g. Triflumuron) greatly
reduces the adult and larval stocks, and control
of darkling beetle populations can be achieved by
the end of the second cycle.
Millipedes outside a turkey house. If you look carefully
you can also see a rat laying around.
4. B io s e c u r i t y f o r p ro f i t
Effective darkling beetle control program
• Identify darkling beetle infestation level
• Keep litter moisture low (key nutrient for larvae and beetles)
• Regular maintenance of water lines will prevent leaking and
will help reduce beetle numbers
• Follow a sound rotational insecticide program in accordance
with label instructions and local legislation
• Darkling beetles can be effectively reduced during the winter
season by combining insecticides and low temperatures (frost).
Darkling beetles
Darkling beetles (Alphitobius diaperinus) are known to eat feed intended for your birds. There can be up to 2 million darkling beetles and
larvae in a turkey house. This is a serious feed consumption issue.
Darkling beetle development cycle. By interrupting the cycle (preferably on multiple
points) you can control the insects.
53
Bird control
Wild birds are the main transmitter of Avian
Influenza and other infectious avian diseases.
Keep wild birds away from your farm.
The main issues are:
• Prevent wild birds getting close (nesting).
• Don’t allow access to feed (spillage).
• Don’t allow access to the house.
• Prevent droppings or dead birds as a source of
contamination.
The iron netting in front of the air inlets is no longer there.
This creates an opportunity for wild birds to enter the house.
Here, pigeons are eating feed before the truck has even
left the feed mill. This is a biosecurity hazard. Make sure
wild birds do not have access to the turkey feed.
Remove dead birds that you find around the farm.
Don’t forget the turkeys themselves. They can spread
diseases to other turkeys on the farm. Remove dead
turkeys daily. This one has been here for a while...
Nesting birds on the turkey farm. Remove all wild birds’ nests and don’t create opportunities for them to start nesting.
54
Turke y S i gnal s
Cleaning and disinfection program
In addition to the cleaning and disinfection procedures after emptying the houses, several areas
should be cleaned during the production period.
• The buffer zone should be cleaned when necessary, but at least twice a year.
• Don’t store cleaning materials in or around the
houses before a cleaning takes place.
• Showers and all other sanitary facilities should
be visibly clean after every use.
• The hygiene lock must be cleaned every day
and disinfected every week.
Taking the time to clean and properly disinfect the
turkey houses in between flocks is mandatory in
order to reduce the risks and break disease cycles.
Repairs must be carried out when the house is
empty. Besides cleaning out the house itself, it is
important to clean the feeding system between
every flock. This prevents diseases from spreading
and spoilage of feed (molds and other contaminants). Remove any feed left in the feeding silo
after delivering the turkeys for slaughter. The new
feed for the new flock must be delivered in a clean
silo; skipping this step is risking your next flock at
their most vulnerable point.
Remember
•
•
•
The quicker the house is emptied and
cleaned, the longer the down time and thus,
the higher the reduction in pathogen load.
Cleaning, washing and disinfection are three
separate steps.
Clean and disinfect feed and water lines after
every flock is shipped, and again before the
new flock is placed.
Before driving into the house with a loader to remove the
old litter make sure all safety measures are observed:
witch off the heat generators and raise or remove the
feeding and drinking lines.
4. B io s e c u r i t y f o r p ro f i t
Broom clean
Remove excess feed from the main silo, hoppers,
feed pans, and fill system. In order to thoroughly
clean, wash and disinfect, disassemble and remove all feeding line elements (pipes, hoppers, shutters, plates). Remove the old litter with a loader/
tractor. Transport the used litter in covered trailers
to a distance of at least two kilometers away from
the farm for composting or processing.
Dry cleaning
Once the house is empty, dry clean the ventilation
and heating systems equipment with a backpack
blower or brush: fan housing, wall inlets and louvers, stoves and heaters, air filters etc.
Clean and cover-up all non-washable equipment
with water-proof protection: electric motors, environmental sensors, heating equipment. Brush the
remaining dust and debris from all surfaces and
don’t forget hard-to-reach places; a pathogen lurking there might cost you your next flock.
Example of a clean-out procedure
Day
Activity
1
Feed/litter removal, a dry clean, disinsection
2
Equipment protection, washing
3
Drying and wet disinfection
4
Drying, disinsection litter delivery and
distribution
5
Litter treatment
6
Brooding equipment set up
7
Preplacement check and nebulization
8-13
Placement preparation
14-28
New flock placement
A clean house with the last remaining litter brushed to the
center in order to be removed by hand. The drinking system
has been emptied as well. Especially in winter make sure to
empty the water lines and drinkers to avoid damage due to
frost.
55
Cleaning the house
Wash the turkey house internally and externally
with a pressure washer (minimum 100 bar /1500 psi),
preferably with hot water (> 40°C/104°F). Wash
the feed silo, front/back sides of the house, walls
and adjacent roads - only at ambient temperature
> 10°C (50°F). For the interior of the house, wash
in the correct sequence: start at the rear of the
house and move to the front, from apex, downwards.
Wash off the detergent from all the house/equipment surfaces as it may later react with the disinfectant and significantly reduce its’ efficiency.
Scrape/sweep the water from the floor. Be certain
that all dirt and debris (organic matter) is removed
in the end. Pay attention to cracks and joints.
Water lines disinfection
Cleaning water lines between flocks is critical for
removing biofilms and debris that accumulate
while drinking lines are in use. Biofilms and debris
allow water supply lines to harbor bacteria and
other potential pathogens. They must be removed
with a disinfectant. This needs to be done at least
24 hours prior to poults placement or moving turkeys into the grow-out house.
Use two products one after the other :
• fill the pipe with an non-foaming alkaline cleaner and leave it to work for 2-4 hours depending on water hardness and temperature.
• rinse the pipe intensively with water.
• fill the pipe with an acid disinfectant allowed
to be in contact with feed like an iodine based,
peroxide based or acid based disinfectant. Let
the disinfectant act for several hours depending on the product.
• rinse the pipe intensively with drinkable water.
All open drinkers should be disassembled and
washed inside and out. Inspect for worn parts and
replace them if needed.
Cleaning and disinfecting the feeding pans
You always work from the source to the end.
So, after cleaning and disinfecting the silo, auger,
hopper and feeding line, it is the feeders’ turn.
Make sure they are completely empty and the total
house is brushed out.
Checking the results
Let someone not involved in the cleaning and
disinfection, check the results and give direct
feedback to the cleaning/disinfection team.
• Visual examination - dirt, debris, dust, fluff,
spoiled feed, etc. that probably carry bacteria.
• Bacteriological analysis - actual bacterial
load of the substrate/environment (total plate
count, measured in CFU).
• Instrumental measurement - fast method for
microbial contamination assessment (luminometry, measured in ATP/RLU).
First cleaning and disinfecting are two separate steps in
the process.
Cleaning should be done thoroughly. Disinfection after a bad clean will not have any effect. And not just the feeder,
don’t forget the inlet as well. The feeding inlet on the left has not been properly cleaned.
56
Drying the house
After washing and before disinfection, drying the
house is necessary. Use of heating and ventilation
systems will speed up the process. Set your heating system on 25-30°C (77-86°F), and ventilation
to 10%. Make sure all the heaters/brooders work
properly. Sometimes they stall after intensive or
careless washing with improper controller protection. It is not always possible to see how clean the
surfaces are until they are dry. Complete the final
inspection after drying, and revisit the cleaning
process if necessary; the loss of time is better than
risking the health of a flock.
Maintenance and repairs should be done prior to
final disinfection, otherwise you might re-infect
the equipment (gas/electrics, lights, feeders/drinkers, leaking nipples, cracked and destroyed concrete floors and wall surfaces). Pest proofing: do
not allow shelters for insects, rodents and check
the presence/condition of the grills/nets on the air
inlets to prevent wild birds entering the house.
Wet disinfection
• Ensure there are no residues of detergent and
water in the house and equipment surfaces
before starting the wet disinfection.
• Check the expiry date and the operational concentration of the disinfectant. Make sure the
chosen disinfectant is compliant with biocidal
regulation. Keep the temperature in the house
around 25°C (77°F) for optimal results in case
of disinfection with formalin.
• Spray the entire building with a strong broad
spectrum disinfectant (bactericidal, virucidal,
yeasticidal, fungicidal).
• Include fans, fan housings, fan louvers, stoves,
drinkers, curtains, bird wire, feed pans and
feed lines.
• Properly dry and ventilate the house after the
wet disinfection for at least two days.
• Document the amount of water and product
used to wash down and disinfect.
Cleaning and disinfection
Drying
Proper storage
‘Clean’ pest control
The purpose of the ‘clean’ insect-control is to
prevent the return of the insects, which managed
to escape or survive the ‘dirty’ eradication, from
their shelters to the clean and warmed up house
with the fresh feed in the feeders. DO NOT apply
insecticides together with the disinfectants. Properly dry the house before applying the insecticide.
If everything is clean and dry, keep it that way and don’t store it in the
house like this.
57
CHAPTER 5
Turkey house climate
Turkeys can be grown in a wide variety of climates. The two fastest growing markets are North
Africa (very hot summers) and Russia (very cold winters). In cold climates the housing and climate
controls must be of a high standard. In very hot conditions, the housing can be much less expensive.
An incorrect climate from an early stage of the flock’s development can severely affect its’ health,
performance and final results.
Ventilation
minimum
H2O, CO2
maximum
O2
Heat
CO, NH3
58
Dust
The house climate is a combination of temperature, air humidity and velocity,
indoor air composition, dust, and light. These factors can all potentially impact
each other.
Climate issues may lead to respiratory problems,
gastro-intestinal dysfunctions and systemic bacterial infections, associated with high levels of NH3,
CO, CO2 and dust. Excessive humidity affects the
litter quality, leading to footpad lesions, breast
blisters, and dermatitis etc. A lot of damage due
to inappropriate microclimate will occur in the
brooding period, when young poults are very vulnerable to climatic stresses. These very common
issues lead to high levels of early culling and mortality or later carcass condemnations at the point
of slaughter.
Turke y S i gnal s
Microclimate
Basic climate requirements
The microclimate is difficult to correctly predict
and standardize. It requires creativity and understanding of turkeys’ needs to be able to maintain
optimal conditions. Each farmer will find his own
specific combinations of setting and approach to
achieve optimal performance (which can rarely be
blindly copied from one farm and/or turkey house
to another).
Most parameters can be measured with electronic
devices, but their values do not necessarily mean
comfort for (all) the birds. Spend time in the turkey house among the birds, watch their behavior,
check the air flow (smoke test), find the critical
areas in the house which are out of the sensor’s
coverage, and try to understand the interrelation
of these parameters to learn how to notice and
react to turkey signals relating to the suboptimal
microclimate.
There are several methods of brooding poults for
the first few weeks of their lives. The traditional
method is to use hover brooders. The poults are
confined to the brooder area by a circle of cardboard for the first week or so of life. Two new
systems are whole house heating as used by the
broiler chicken industry and underfloor heating.
The latter is usually installed at the time the
house is erected.
Parameter
Recommended level
Temperature (air)
34-37°C (93-99°F) (brooding). Gradual decrease to 12-14°C (54-57°F) in fattening
Temperature (floor)
Perfect: 1-2°C (2-4°F) below air temperature.
Minimum: 28°C (82°F)
Carbon dioxide (CO2)
< 3,000 ppm
Carbon monoxide (CO)
< 10 ppm (ideally 0)
Relative Humidity
45-65%
Ammonia (NH3)
< 10 ppm (humans can smell 5 ppm)
Hydrogen sulfide (H2S)
< 5 ppm (ideally 0) (humans can smell 0.5 ppm)
Sulfur dioxide (SO2)
0
Ventilation rate, m3/kg/h Depends on the outside climate, farm layout
and age of birds
Air speed at bird level
< 0.1 m/sec (0.22 mph) (in winter, in brooding)
< 0.2 m/sec (0.45 mph) (in rearing until 6 weeks)
1.5-2.5 m/sec (3.4-5.6 mph) (only in summer,
only after 6 weeks)
Temperature difference
at bird level
< 1°C (2°F) (in rearing until 6 weeks)
Negative pressure
0.5-1.0 Pa/m of turkey house width
Dust
< 3 mg/m3
Light
100-20 lux (9-2 fc). 8 hours of darkness per day
Unable to regulate temperature, Transition period
environment crucial
around 5-7 days old
0
(28)0
incubation
7
brooding
Poults produce their own heat and can
self-regulate their body temperature
28-63
rearing
105-140
fattening
development
growth
Poults cannot regulate their body temperature properly. For the first 5-7 days
their body temperature varies in line with their environment (poikilothermic).
If the temperature is too high or too low during the first week, it will have a
negative effect on the poults’ activity, uniformity, daily growth, livability, feed
conversion and final body weight.
Radiation
Evaporation
Convection
80%
55%
Conduction
Birds can’t sweat, so they lose heat through conduction,
radiation, convection and evaporation. Minimize these
losses in very young poults. With older birds it is often
the other way around as excessive heat removal may be
required.
5. Tur k e y h o u se c l i m a t e
15%
15%
30%
5%
A turkey poult usually loses about half of its heat through the skin, and half
through breathing. If the litter layer is too thick, the poult will have to expel heat
through panting. So, with the thickness of the litter layer, you can influence
the heat regulation of the birds both in winter (undesired heat loss for young
poults) and in summer (desired cooling for older birds).
59
Floor temperature
Air temperature
The first thing poults feel after being unloaded from
the transportation crates or boxes is the floor/litter
temperature. It strongly influences their activity and
health from their very first moments in the turkey
house, and predetermines the overall performance
of the full rearing and fattening cycle. Make sure the
house and floor are properly pre-heated.
Air temperature is the second most important
parameter after floor temperature. If hover-type
brooders are used, the temperature should be
approximately 35°C (95°F) in the first days. Take
this temperature reading at the edge of the hover
approximately 5 cm above the litter, or at the
height of the poults’ back. Be sure to check the
accuracy of the thermometer before the poults
arrive. Reduce the hover temperature by around
2.8°C (5°F) weekly until it registers 18-20°C
(64-68°F) or is equivalent to the prevailing nighttime environmental temperature — whichever is
greater. During the first weeks, room temperature
should be at least 21°C (70°F). This helps to prevent any drafts on the poults and wide temperature
fluctuations in the brooder room. If the weather is
warm during the brooding period, the heat can be
turned down at the beginning of the second week.
However, heat should be maintained during the
evening hours for a longer period. In mild climates,
little or no heating is required after the sixth week,
depending on the weather conditions.
Put your equipment back in place before the new flock
arrives! This T-sensor is still tied up under the ceiling (from
the clean-out period) and will indicate a high temperature.
The poults will be huddling on the floor, with the computer
not running the heaters.
X
40°C
33-35°C
X
38°C
42°C (108°F)
40°C (104°F)
✓
40°C (104°F)
35°C (95°F)
40°C (104°F)
30°C
33°C (91°F)
31°C (88°F)
24°C
24°C (75°F)
28-30°C (82-86°F)
The floor is cold 24°C (75°F), air temperature is OK (33-35°C/91-95°F): strong/active
poults feel comfortable, the weak/passive
poults are losing heat through conduction on
the cold floor.
60
37°C (99°F)
Heating up the house to 37°C (99°F) will
partially solve the problem of the cold floor for
the minority - the weak poults, but it creates
an overheating problem for the majority - the
active poults.
Don’t blindly trust instruments, regularly send your tools
out for accurate calibration. Compare them with similar
tools.
Heating up the floor before litter distribution
is the key to a successful brooding period
for all categories of poults (minimal difference
between floor and air temperature).
At best your floor temperature should be about 3-4°C (5-7°F) below air temperature, (28°C/82°F as minimum). If floor temperature gets too low, there will
be condensation on the floor.
Relative humidity
The effect of air temperature and relative humidity
are closely related. This can be illustrated with a
sponge. Hot air is a sponge that can absorb water.
When the air gets colder, air molecules move closer together so there is less space for moisture, the
same as when you squeeze a sponge. This is fine
until the sponge is saturated, after that water will
begin dripping out of the sponge. In the air, this
manifests itself as condensation.
LOOK-THINK-ACT
When do poults suffer from heat stress?
You’d expect poults to experience heat stress at the hottest time of
the day. But this problem usually occurs at the end of the day as the
air cools down and the RH rises rapidly. Then the birds are unable
to get rid of their excess heat (always look at the combination of
temperature and RH).
Hot air, can hold a lot of moisture
But as the air cools and shrinks...
Mollier diagram
50
RH 100%
45
Absolute humidity (g/kg)
In this graph temperature is plotted against the absolute
amount of moisture in the air (Mollier diagram). The curved
lines show the relative humidity (RH). If the initial temperature is 35°C (95°F) with RH of 60% (A) and temperature
drops, then relative humidity rises quickly (absolute moisture
content in the air doesn’t change): move horizontally to the
left. With higher RH, less evaporation is possible; poults find
it harder to get rid of excess heat. In this example, if the air
cools down to 26°C (79°F), humidity has increased to the
maximum of 100% and the poults will die from heat stress
(B).
...it can no longer retain or absorb
moisture (so evaporation ends and
condensation may occur)
40
RH 80%
35
30
B
25
A
20
RH 60%
RH 40%
15
10
5
0
0
(32)
5
(41)
10
50)
15
(59)
20
(68)
25
(77)
30
(86)
35
(95)
40
(104)
Temperature °C (°F)
5. Tur k e y h o u se c l i m a t e
61
Comfortable climate
Air quality
When do poults feel comfortable? For them a relative humidity (RH) of 50-60% is ideal. As a rule
of thumb you can use the temperature/humidity
index: T°C + RH%. 90 is a comfortable figure.
At about 5 points above the comfortable value,
the poults begin suffering from heat stress. If it
remains above 115 for a prolonged period, they
will die. When poults are hot, increasing the temperature can sometimes actually help them cool
down because the RH drops and they can evaporate more moisture. Remember a simple rule:
+1°C (2°F) reduces the RH by approximately 3%!
Good to know: poults will tolerate warm and even
hot conditions more easily than a slight chill!
Air quality is impacted by the turkeys’ presence,
type of bedding material and litter condition,
ventilation, watering, and heating method (direct/
indirect combustion). If you have several houses,
you may notice turkeys in different houses doing
different things. If the birds in one house are less
active than those in another, this could be a signal that the climate is incorrect. You can monitor
most gases yourself using gas detection tubes.
There is plenty of oxygen in the air, so oxygen level
is seldom a problem, but the increase of CO2 and
other noxious gases can spell disaster. The most
important noxious gases:
• Carbon dioxide (CO2)
• Carbon monoxide (CO)
• Ammonia (NH3)
Temperature (°C)
100
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Danger
95
90
LOOK-THINK-ACT
What does this behavior tell you?
Humidity (%)
85
80
75
70
95
Muggy
65
60
55
50
45
85
Comfortable
Too low
Keep the birds within the comfort zone. If you reach the
red area, birds will die. In the blue area they will suffer
cold stress, which will seriously impact their feed conversion.
Birds are huddling together between the feeding and drinking lines in
large and small groups. Prompt action is needed: raise the temperature by 0.5-1.0°C (1-2°F) and check the flock behavior after 20-30
minutes. The huddling could also be related to a disease or a strong
post-vaccination reaction (fever). In any case - increase the temperature to help the flock make a quicker recovery.
62
After placing the poults, protect the flock from any possible drafts, especially in winter! Seal the doors, unused
ventilation system elements, etc.
Turke y S i gnal s
Measuring CO2
CO2 (carbon dioxide)
In poultry houses CO2 largely originates from air
exhaled by the birds; the heavier they get, the
more CO2 is produced. In brooding houses, most
of the CO2 is produced by heating equipment (gas
combustion). CO2 is a heavy gas, so the concentration at bird level can be much higher than at
1.5 m (5 ft) height. CO2 levels should ideally be
below 3,000 ppm (EU standard < 2,500 ppm). In
high concentrations CO2 makes the birds lethargic
and apathetic. It will also give you a headache and
shallow breathing if you spend a long enough time
in the house.
CO (carbon monoxide)
CO is an odorless, very dangerous gas for both
birds and people. CO is the result of incomplete
combustion of gases. Improperly tuned heaters
(dirty filters) operating at off-design levels, in
combination with low ventilation levels, decrease
combustion efficiency, resulting in increased CO
emissions. Keep carbon monoxide below 10 ppm.
Data loggers are important to make sure these levels are not exceeded.

Too low CO2 level:
Ok in case of summer/tunnel ventilation, but suspicious
in a brooder house.
Overventilation?

Optimal CO2 level:
below 2,500 ppm is
optimal for any age
and any season.

High CO2 level:
above 3,000 ppm
indicates insufficient
ventilation and/or
excessive heating.
Left: In a house heated by brooder-stoves it is not surprising to see CO
levels much above the permitted limits, especially during the coldest season. Right: In a house with jet heaters the situation is the opposite - CO2
is the main problem. Increase ventilation (if it’s not too cold outside).
Complete combustion is usually characterized by a blue
flame. If you see another color: ask your technical service
to adjust the heater settings.
By clipping a CO2 meter on you boot, you can measure
CO2 at bird level. On a set level the alarm will go off and
the farmers knows that he has to adjust the ventilation.
To detect CO every turkey house must be equipped with
an automatic sensor system.
CO level near the brooders is the highest in the turkey
house. Using both local and whole house heating – can
be a double trouble (high CO2 and CO). Ventilate more!
63
LOOK-THINK-ACT
What do you think when you see this?
Dust is not only unhealthy when inhaled, dust accumulation on heaters is a serious fire hazard. Regularly clean your heaters and inlets.
Effect of ammonia levels on production at 4 weeks
NH3
(ppm)
Feed intake
(kg, pounds)
Live weight
(kg, pounds)
Variation in flock
(C.V.)
0
2.19 (4.83)
1.36 (3.00)
12.1%
25
2.14 (4.72)
1.34 (2.95)
13.2%
50
1.86 (4.10)
1.10 (2.43)
14.2%
75
1.84 (4.06)
1.12 (2.47)
16.8%
source: Berry Lott, 2002
Dust facts
64
Sources
Amount of dust
depends on:
The dustiest
types of litter
•
•
•
•
•
•
•
•
•
•
•
•
•
Litter
Feed
Manure
Feathers
Skin
Temperature
Air Speed
Litter type and moisture
Feed structure
Relative humidity of the air
Too much ammonia can even result in blindness. This is a rare event and would indicate a
potentially catastrophic ventilation issue.
Peat (turf)
Dry sawdust
Chopped straw
Ammonia (NH3)
If you smell ammonia on entering the house, the
level is too high (> 5 ppm). NH3 is a product of
bacteriological processes in the litter. Ammonia
is lighter than air and therefore rises in the turkey
house. The ammonia level in the poultry house
depends on ventilation, temperature, relative
humidity and stocking density. Ammonia production is closely related to moisture level in the litter, and so to the relative humidity of the air! This
means that proper control of RH% in the house
automatically controls ammonia emission from
the litter. Carefully watch the watering system for
leakages as well. High ammonia and dust levels
affect the poults’ mucous membranes and makes
them more susceptible to respiratory disease.
NH3 is well known to lower the feed intake, daily
growth and flock uniformity.
Dust
The long turkey production cycle creates many
conditions for dust formation and accumulation.
Highly contaminated dust is a trigger of respiratory disease, and can significantly reduce the heating and ventilation capacity of the turkey house
equipment. It also acts as a vector for micro-organisms. High dust levels can particularly lead to
Aspergillus infections of the air sacs in turkeys of
any age. Keeping RH% low and working hard on
the litter quality can be very positive for the leg
health, but becomes the cause of a dusty environment, so keep the balance right. Try to keep the
dust sources under control (fines in the feed, sawdust in the litter), maintain a RH of 50-60%. You
could use a high-pressure fogging system to keep
the dust in the turkey house down.
With the lights on you can easily see the dust
in the turkey house as a kind of mist.
Dust accumulates at the air inlets, hindering
a free airflow.
Turke y S i gnal s
Ventilation system choice
Ventilation regimes depend on seasons (minimum
ventilation for winter, maximum for summer),
and weather conditions during the transitional
periods (heat/rain and day/night shifts in autumn
and spring). Not all ventilation systems work
as expected! This is not only due to improper
application of the existing tools, but an initially
incorrect building design, insulation materials,
heating and ventilation equipment, which eventually require more manual intervention from the
operator. Let a climate expert check both the climate computer and the climate twice a year. The
expert can adjust the manufacturer’s settings if
necessary and pick up on changes in the sensors
which could indicate that the climate is not being
optimally controlled. Also use your own common
sense: You get used to bad air quite quickly, so
take note of the impression you get when you
enter and leave the house.
Natural ventilation (open type houses)
Natural ventilation doesn’t make use of fans for
incoming or outgoing air. The fresh air enters the
house via open inlets, often fitted with controlled
valves, panels or curtains, and leaves through the
same openings and/or the roof. Natural ventilation
is often seen as a simple and inexpensive system.
Whether that is true depends on the results that
can be achieved from such a house. Due to the
very high initial temperature requirements it cannot be implemented for brooding houses, especially in cold and temperate climatic zones.
Mechanical (forced) ventilation
Even in areas where natural ventilation can work
well, farmers are increasingly using mechanical
ventilation. The investment and energy use are
higher, but it offers more control options and is
therefore more likely to produce good results. The
air is expelled from the house by fans creating a
pressure gradient. The slight negative pressure in
the house pulls air in via all openings at a similar
rate. It is therefore important that there are no
openings in addition to the air inlets: they could
disrupt the entire system.
Types of ventilation systems, based on air
pressure management
Natural ventilation is based on the principle that the warm
air, produced by the birds is sucked out of the house
through a roof opening (chimney effect). This system is
acceptable for turkey fattening houses in moderate - cold
climates.
Turkey house with natural ventilation in Spain.
5. Tur k e y h o u se c l i m a t e
Equal pressure
Open houses with natural ventilation
in hot climate
Excessive
(over)pressure
Old and new systems based on
preconditioned air pumped into the
house through air tubes
Negative
Most common ventilation systems
(under)pressure used in regions with moderate/cold
climate
Curtains can be closed with natural ventilation for temperature control during the night or cold season. Make
sure there is adequate ventilation for the necessary gas
exchange.
65
LOOK-THINK-ACT
What do you think when you see this?
Front
Middle
Back
In a perfect situation, the temperature variations inside the turkey
brooding house should not exceed 1°C (2°F). A poorly insulated
house will never have a uniform temperature. In this situation with
leaking doors/ back wall outlets, temperature variation is almost 4°C
(7°F), the air velocity is above 0.1 m/sec (0.2 mph). This is unacceptable, and the birds confirm that by avoiding cold zones and piling up
due to the cold. The older the turkeys are, the more tolerant they are
to temperature variation.
Minimum ventilation
Minimum ventilation is necessary to ensure that
turkeys have enough fresh air, to remove waste
gases and moisture. Usually a very minimal level
of ventilation is provided during the first week to
save on heating costs, and more importantly –
avoid undesirable drafts. Throughout the cycle,
more waste gases and moisture are produced and
the amount of air that must be refreshed increases
by the hour. Water that is not removed via ventilation ends up in the litter that will (as a result),
become wet. In the first week the poults may need
between 0.04 m³/bird/h (0.7 m³/kg/h) to 0.1 m³/
bird/h of fresh air (1.7 m³/kg/h). With age and actual temperature, the ventilation rate will go up. The
actual amount of minimum ventilation depends
on the type of heating, because often most of
the CO2 is produced by gas combustion (not the
birds).
Airtight and well insulated houses
Although minimum ventilation is required, it
should be regulated, so a house should be airtight and well insulated. Without this you will not
be able to maintain a uniform temperature and
controlled air flow. A good airtight poultry house
should have a negative pressure of at least 50 Pa
with all inlets closed, and minimum (roof) ventilation on.
Chilled birds.
A non-airtight house creates a potential risk of drafts and piling up, especially
during the night.
66
Poor house construction and insulation increases the risk
of draft and condensation during the cold seasons.
Turke y S i gnal s
LOOK-THINK-ACT
A farmer has covered an inlet to prevent cold
air entering. What do you think about this
method?
Condensation and subsequent icing in winter at a cold
spot in the corner of a house. The water drips on the
litter and feed, and the fluid can harbor many microorganisms.
In the turkey house with negative-pressure based ventilation the insulation of the inlets is done from the inside. This makes no sense, since the
plastic will be pulled into the house and start leaking from condensation.
Condensation on the ceiling due to bad house construction/insulation can become a big problem in winter. The
water drips on the litter and feed, and the fluid can harbor
many micro-organisms and trigger the growth of molds.
Multiple icicles hanging from the roof of the turkey house
is a signal of poor roof insulation and means the loss of
heating energy will result.
A smoke test visualizing the cold air falling down on the
birds from non-insulated front wall inlets.
An IR camera can help reveal much more leakage, like
here at a ventilation duct.
5. Tur k e y h o u se c l i m a t e
67
LOOK-THINK-ACT
What is the purpose of this bottle?
For an accurate air pressure assessment, the external pressure
control pipe should be carefully protected from the wind. The bottle
prevents wind disturbing the reading.
measuring
air pressure
in the turkey
house
measuring
air pressure
outside
indicator of a difference in air pressure
Negative pressure can be measured by special equipment, measuring air
pressure both inside and outside the house. It can also be calculated based
on the air speed in the air inlet.
Negative pressure is the key
Negative (under)pressure is when the air pressure
inside the turkey house is lower than the pressure
outside the house. It is created as a result of the
exhaust fans operation. This negative pressure is
necessary to have control of air movement (speed
and trajectory). The required negative pressure
in a poultry house is related to the width of the
house. It is regulated by the ventilation rate and
the opening of the air inlets. As a general rule:
for each meter of house width the negative pressure should be around -1 Pa. So, a house of 18 m
(59 ft) wide should have a negative pressure of -18
Pa to create the airspeed required to push the air
up to the center of the house along the ceiling.
It is almost impossible to achieve -1 Pa/m in the
first 7-10 days of a flock’s life due to the very small
amount of ventilation needed. Other factors determining the level of negative pressure:
• In cold seasons the negative pressure should
be ~10% higher, because cold air is heavier than
warm air, so higher pressure is required to prevent air falling down close to the side walls.
• In the warmer seasons and with older birds (from
4 weeks) negative pressure can be ~10% lower,
because the temperature differences inside and
outside are small - the air will not fall easily.
• With a cross-ventilation system the negative
pressure should be -2 Pa/m of house width,
because the air must travel twice the distance
across the house.
• Higher negative pressure is required in the
houses with inlets located in the roof, because
the incoming air has more obstacles to pass
on its way into the house.
To be able to supply reliable data the pressure and temperature sensors require the correct protection.
The cover on the right one has come off, repair this.
68
Turke y S i gnal s
Air velocity and trajectory
The air velocity should never exceed 0.1 m/sec
(0.2 mph) in brooding, 0.2 m/sec (0.4 mph) in
rearing and fattening and, unless the birds start
suffering from heat stress. During the hot season
it should not exceed 2.5 m/sec (6 mph), because
higher velocities lose efficiency but increase the
risk of stress. During the installation of ventilation
systems, their performance should exceed your
projected requirements by 20%, to take into consideration system wear and cleanliness. There is
a direct relation between the negative pressure in
the house and air velocity.
Coanda effect
Minimum ventilation (small poults until 28 days) + winter
ventilation (any age)
Maximum ventilation/summer ventilation after 28 days.
Make use of the Coanda effect: the smoother
the surface of the object, the easier the air
stream moves along this surface, requiring less
initial input. So, a smooth wall/ceiling surface
without obstacles helps the incoming air ‘stick’
to it and run smoothly to the center of the turkey
house. You will need less negative pressure and
initial airspeed to create the trajectory you need.
What we want in cold climate zones – high ridge with a
warm air mass.
This inlet could not be worse: no flap, flat rigged ceiling,
a cable channel and a gas pipe – all in the way of the
incoming air!
Correct
There is plenty of room above the tiers to allow the
air right into the middle of the house. You can also
direct air to the middle of the house with pipes or
ducts from outside, running along the ceiling to the
middle.
What is often seen: ‘tunnel’ type of houses, which are not
suitable in cold climate conditions.
Incorrect
Poor air circulation can occur in houses with low ceilings and a relatively large number of obstacles. Air
does not circulate properly in houses which are too
low.
69
Possible air distribution scenarios
It is impossible to assess the air distribution in
the turkey house without visualizing it. Complete
a smoke test to see how quickly the air is flowing
through the house. You don’t have to take the turkeys out of the house to do this.
A simple solution if you don’t have a smoking machine
is to use the tape from an old music cassette. It’s very
lightweight and easily flows with the air stream, indicating
its’ direction.
What can you expect to see?
70
Too much negative pressure / speed
• The fresh, cold air in the middle falls and there is
little air movement at the sides.
• The poults avoid the middle and go to the sides
of the house, resulting in damp litter.
• Reduce the negative pressure.
Too little negative pressure / speed
• The fresh cold air falls too quickly and is therefore not being heated up enough. The poults
keep to the outermost quarters and the middle
of the house.
• This has created two empty strips down the
length of the house: a zebra crossing effect.
• Increase the negative pressure.
Too little opening
• The poults move away from the edges and are
mainly in the middle.
• The flaps are too tightly shut, so there is too little
air entering through each flap, which dissipates
too quickly.
• Open some of the flaps about two fingers wide.
‘Reversed’
• In hot weather the flaps will turn.
• The air will pass right over the poults at high
velocity.
• This will make the air feel quite cool near the birds
(wind chill effect). This should only be done deliberately if the ambient temperature is very high.
Turke y S i gnal s
Source: Henk Rodenboog
Good ventilation
Correct airflow for minimum ventilation: cold air is coming in through the inlets, due to negative pressure in
the house. The volume will increase because the cold
and warm air mix together and the speed decreases.
Once on the floor, the air is pulled back to the wall/
inlets because of the Coanda effect.
Effective temperature (°C)
Interaction of temperature, RH and
air velocity
34
35°C (95°F)
30
26
29,5°C (85°F)
22
18
21°C (70°F)
14
0
0.5
1
1.5
Air velocity (m/s)
2
2.5
Effective temperature for fully feathered poults (from 28
days) based on the air temperature, RH% and velocity.
Chill effect and age
Age
Experienced temp. difference
1 day old
- 8°C (14°F)
7 days old
- 5.5°C (10°F)
21 days old
- 4°C (7°F)
35 days old
- 3°C (5°F)
The lower temperature experienced by the turkeys does
not only depend on air speed, but also on age. Younger
turkeys are much more susceptible (small body size, less
subcutaneous fat).
For most inlets a minimum opening of 3-4 cm (1.2-1.6 in)
is necessary for a good air flow. You can realize this in the
first week (when little ventilation is required) by not opening
all the inlets at the same time. Here only every third inlet has
been opened.
Bird comfort is created by the joint influence of
temperature, relative humidity and air velocity
(= effective temperature). You can use air velocity
to cool birds even at higher ambient temperatures,
but above 38°C (100°F) this wind chill effect is not
effective anymore. Be careful about starting cooling too early. Even for adult birds a cold, humid
draft can be dangerous. The cooling effect increases significantly at low temperatures, high humidity
and high air speed.
Inlets
Based on the minimum ventilation level, the work
of the inlets determines the negative pressure,
incoming air velocity and airflow trajectory in the
turkey house. Inlet design, location, number and
management are very important for controlling the
air distribution in the house and protection of the
young poults from draft and disease. Standard for
air inlet opening: 0.5-1 cm2 per 1 m3 ventilation
capacity/hour.
Air mass is as important as velocity
With small birds only a very small part of the air
inlet capacity is necessary. This can be realized by
automatically creating a small simultaneous opening of every inlet. But the problem is the small
amount of air coming in through each inlet. This
small volume has no mass and will not reach the
center of the house. It is a better idea to use less
inlets, but opened wider. The bigger the opening
– the more air coming in per inlet and the less
resistance it has, the further the air stream moves
in the house.
The cold air comes in at the same pressure and velocity, but look at the distance of spread from the inlet: with a
small opening there is more air disturbance.
5. Tur k e y h o u se c l i m a t e
71
72
After negative pressure is established, a smoke test will help to
adjust the position of your flap, especially if there are a lot of obstacles in the way of the air stream on its way to the center of the
turkey house.
You need to set up all your inlet flaps in the turkey house in the
same position. It’s easy when your inlets have sidewall guides with
fixed markings.
Without markings, a handmade template could be a tool to put all
flaps in the same position.
A minimum opening of 3-4 cm (1.2-1.6 in) should be used from a
day old.
Sudden increase in static pressure might not only be ventilation
system errors. Regularly check your inlets (especially after sudden
temperature fluctuations), for blockage from dust or snow.
Poor inlet insulation leads to condensation. Dust sticks to the
moisture and accumulates, leading to faulty operation. Keep your
ventilation equipment clean. Dust and ice significantly reduce the
capacity of your inlets.
Turke y S i gnal s
Heating systems
A variety of heaters are available - all with their
own pros and cons. The brooding system you
use is a determining factor in the type of heater you should choose. A standard for heating
capacity is 80-120 W/m2 (Europe). In the colder
area of Central Russia, a minimum of 220 W/m2 is
required.
Warm air heaters
High-intensity IR heaters
Pancake brooder
Warm air heaters provide less uniform
heat than can be achieved with other
heating methods. They are often placed
at the end of the poultry house with the
heated air directed toward the middle of
the house. Consequently, there tends to
be an area in the middle of the house that
is warmer than the sides and ends.
A mixture of fuel and air is burned, producing surface temperatures of 870-980°C
(1600-1800°F) and an orange glow.
Because of the creation of carbon dioxide
and water, more ventilation is required.
The extra ventilation also tends to cool the
environment, requiring even more heating…
A major disadvantage is incomplete combustion due to the filter blockage from dust,
leading to the accumulation of high levels of
CO in the house.
The pancake brooder (gas radiator/
jet brooder) is widely used. They are
relatively small and heat output is low.
Pancake brooders are often located about
one meter above the floor. These heaters
transfer about 40% of their energy as infrared heat to the floor and 60% to the air
as convective heat (often lost through the
roof). Pancake heaters involve an open
flame and thus add moisture and CO2 to
the house environment, requiring extra
ventilation during which heat is lost.
Such heaters work fine in mild climates in
brooding/rearing houses in combination
with high intensity IR brooders, but never
alone. Due to their very low position on
the wall large males easily destroy the
nozzles and they need repair/replacement
for every cycle.
Since the physical size of a high-intensity
IR heater is small, the heat felt from the
unit is localized in a small area. These
heaters are more appropriate for spot
heating applications. Use two IR heaters
per brooder ring to avoid problems if one
of them stops heating.
Pancake brooder heaters are normally
mounted at a low level. In time they are
elevated to decrease temperature at floor
level, if they are not easily adjustable. In
this case they are not spot-heating anymore, but more whole house heating.
The brooder filters require regular cleaning and/or replacement: a very
labor intensive job!
5. Tur k e y h o u se c l i m a t e
The middle of the house will be properly heated, but the side walls
are often not reached, leaving cold spots. So, gas stove heaters
of this type should be directed outwards to the house wall to avoid
this problem.
73
Indirect heaters (boilers)
Hot-water convection heater
Wet systems are expensive but popular due to
their multi-functionality and good heat distribution. The pipes radiate heat in all directions. Wet
systems are slow to adjust to outside climate
changes. The major advantage is the complete
absence of any toxic gases and the lowest ventilation cost among all heating systems. In dusty
conditions, convectors tend to lose their heating
capacity very quickly. Therefore, regular and thorough cleaning is absolutely necessary.
Gas-fired, low-intensity infrared heaters
Gas-fired, low-intensity infrared heaters mix gas
and air, then burn it inside a heat exchanger tube,
with maximum temperatures generally between
480°C and 595°C (900-1100°F). The long heat
exchanger tube allows the heat to be spread over
a much larger area, compared to the more localized heat from a high-intensity heater. The exhaust
gases are removed via a chimney so that the
house air remains free of harmful gases.
Example of hot water heat exchanger.
There is a temperature difference between the beginning and the end of the tube of a gas-fired, low-intensity infrared heater, so be prepared for some temperature fluctuation in the turkey house.
74
Turke y S i gnal s
Jet heaters
Jet heaters combust gases and blow the heat into
the room. There are direct and indirect gas jet
heaters. With indirect heaters, combustion gases
are expelled outside the house.
It’s preferable to have multiple smaller capacity
blowers, than fewer of higher capacity. The shorter
the distance between the heaters – the more uniform the climate will be in the turkey house.
A big mistake is ‘mirroring’ the ventilation and
heating equipment in the turkey house in order to
save costs of installation.
✓
Be careful with the height and direction of your jet heaters:
1w
rong position: too low, too close to the wall and inlet
– too much turbulence of cold air at bird level.
2c
orrect position: min. 3 m (10 ft) from the wall,
min. 1.7 m (6 ft) high – away from the inlets.
X
Correct heaters’ direction (clockwise) – the heater fan
rotation helps to push the cold air up to the ceiling by
mixing with the warm air.
Incorrect heaters’ direction (counterclockwise) – the fan
rotation pushes the incoming cold air down to the floor
before it’s been preheated, creating a cold draft on the
floor.
Correct direction, but wrong height and wrong distance
from the wall.
Wrong direction, wrong height and wrong distance from
the wall.
It’s not a good idea to direct a jet heater down to the floor (left). Its position should be strictly horizontal or - if it’s hanging low
- slightly upwards to avoid stressful airspeed at bird level (right). When the heaters start running, they will ‘eat’ the air and pull
slightly backwards. The left heater will be even worse, the right heater will be almost horizontal.
75
Cooling system
In hot climates cooling could be required. The
act of cooling can sometimes actually cause heat
stress. In higher RH, birds lose very little water
due to evaporation, so they are unable to cool
down effectively. Lowering the temperature will
cause the RH to increase even further. The answer
is not to lower the temperature, but to ventilate
more to remove moist air from the house.
A turkey house with cooling pads installed in the front wall.
A fogging system that creates a mist just above the inlets.
Evaporative cooling in reducing temperature
Evaporative cooling can be an effective method
to reduce the temperature of incoming air and is
effective when temperatures are over 27°C (81°F)
and RH is below 80%. Evaporative cooling is detrimental when humidity is over this mark, as turkeys can no longer lose heat through respiration.
Overuse of evaporative cooling can also cause wet
litter. Evaporative cooling can reduce air temperatures by 8°C (14°F). Don’t overdo it: younger birds
that are not fully feathered could be chilled very
quickly.
Cool cell pads are mounted at the tunnel inlet
end and water is slowly sprayed or trickled over
the wet pads to cool the incoming air. It is an
effective method, but also an expensive one and
usually difficult to maintain.
High pressure fogging also uses evaporation
of water to lower air temperature. High pressure
pumps push water though nozzles at the inlet to
create a fine mist.
Due to corrosion these nozzles have become blocked. Check your high-pressure fogging system before placing a new flock. It must
be sanitized as well, but don’t keep the disinfectant inside for longer than 24 hours, otherwise it will destroy the nozzles and they will be
either blocked or dripping, causing the litter to become wet.
76
Turke y S i gnal s
Lighting
Light intensity and day length will influence activity, feed consumption, leg health and cannibalism, making it a very important management tool.
Young poults need intense light to enable them to
find feed and water, thereby preventing starvation
or dehydration. It is particularly helpful if it can
make the water sparkle as this attracts the poults
attention and helps them to learn to drink. On
arrival at the farm, the poults are tired having had
the stress of hatching, handling in the hatchery,
and transportation to the farm. After two hours
or so, it is good practice to turn the lights out for
two hours, to induce sleep. This can be repeated
during the first 24 hours as happens in nature with
the mother hen. After that the turkeys should be
gradually given at least 8 hours of darkness. Heavy
hens require a step-down lighting program, where
the length of the dark period gradually increases
in order to avoid the hens from maturing early. A
dark period is important to develop good bone
structure and strong legs. During darkness, the
production of a chemical called serotonin increases. It has several roles, one of which is the
transport of calcium in the blood stream for the
formation of bones. Turkeys kept on continuous
light will develop leg problems.
If poults are brooded under artificial light conditions only, care should be given to the light sources.
Use dimmable neon tubes or LED´s emitting a
daylight spectrum to imitate outside conditions.
Aging warm white neon tubes will lose power in
the blue spectrum leading to increased rates of
starve-outs/non-starters at five days of age.
LOOK-THINK-ACT
What is incorrect about this heater?
Blue flame, so good combustion, good distance from the wall and
not too close to the litter. But a heater in an outward direction! It
makes no sense to heat the walls.
LOOK-THINK-ACT
What does an orange flame tell you?
Incomplete combustion is characterized by an orange colored flame.
This means CO production and low heater efficiency. Check the
heaters when you see this.
5. Tur k e y h o u se c l i m a t e
77
CHAPTER 6
Litter management
Because turkeys spend far more time on the litter than the ‘short cycle’ broiler chickens, litter management is of key importance. Many issues with turkey health and meat quality originate from poor
litter management. Make sure the turkeys house is well prepared before the arrival of day-old poults.
A nice layer of litter for a good start and after that the challenge is to maintain this level of litter quality.
Litter material insulates the floor and helps to
conserve heat while providing increased comfort
for the birds. It also dilutes and absorbs moisture
from fecal matter, condensation from bird respiration, and water spilt from drinkers. Providing a soft,
spongy surface on which turkeys can rest, aids the
prevention of breast blisters, as well as helping to
satisfy their dust bathing and scratching instincts.
Fresh litter should be used for each crop. It should
78
be put down after cleaning and disinfection to
prevent reinfection by pathogens. Litter should be
spread to provide a smooth, even surface (min.
7 cm (3 in) in depth during the Spring/Summer
– and at least 10 cm (4 in) for Autumn/Winter).
Where underfloor heating is being used, litter
depth can be reduced, but ensure there is enough
to provide comfort for the birds.
Turke y S i gnal s
Litter storage
The choice of good litter material is important,
but if it is not used immediately, the material can
deteriorate fast due to environmental influences. Storage is always necessary, since during the
production cycle you will need to top up the litter
layer regularly, especially when wet spots have
appeared in the turkey house. Adding litter material is generally just part of routine litter management.
Make sure storage is performed correctly. It should
be safely stored away in dry conditions, ideally not
in contact with the birds.
You may store just enough for the current flock
in a fenced off area in the house. But don't use
a storage area in the turkey house with the flock
for consecutive flocks since you might carry over
pathogens through this litter material. Wet, molded litter provides a very poor start for turkeys.
Litter should be stored in a facility protected from the weather and
secure from access by vermin, birds or other animals.
These wood shavings are well fenced off and will only be used
for this flock. By storing litter for the whole period in the house,
you avoid introducing new litter material into the sealed house and
stressing the flock.
Under no circumstances should it be stored outside! This will
certainly lead to the development of molds and invite all kinds of
creatures to make it their home.
Litter should be spread evenly throughout the house and
smoothed to one level, especially within the initial brooding areas.
6. L itt e r m a n a g e m e n t
79
Litter on concrete floors
X
✓
1
2
If the floor is cold a thick layer of insulating litter can actually make it harder to warm up this floor. Warm litter on a cold surface can even result in
condensation on the floor which can dampen the litter from underneath. So, it’s always better to start warming up the floor before spreading out
the litter.
80
Concrete floors need a special approach. A lot of heat from the previous batch of birds can be retained in the sand layer underneath the
concrete floor. In some cases, you can keep your heating costs down
by using this residual heat.
To prevent poults from eating litter, you can cover the litter with
paper for the first 2-3 days. Extra benefit: it provides a surface for
supplemental feeding. This paper should have a coarse surface to
provide good grip for your poults. Be careful it doesn’t get slippery
around the drinkers, since that would have the opposite effect...
A cold spot under the litter caused local condensation. The moisture will make the litter wet and cold.
To prevent mold infections (e.g. aspergillosis) it is preferable, in
addition to whole house fumigation and disinfection, to spray the
litter on the floor (before poult delivery), with a fungicide, such as
propionic acid. Turkeys are very susceptible to molds!
Turke y S i gnal s
Litter materials
Types of litter
Moistureabsorbing
Dust Turkey health, remarks
Good litter materials should be dry, absorbent
and friable, provide insulation and be free from
contaminants. The most important characteristics
of litter are its ability to absorb and emit moisture
along with the absence of dust.
Cost, availability and your manure processing
method are all factors that determine which litter
you use. Wood shavings and chopped straw are
commonly used litter materials for turkeys.
Very coarse litter can also contribute to leg disorders, while fine materials can be too dusty. In
addition, small-particle litter leads to an increased
amount of caked litter around waterers and feeders. This, in turn, can lead to increased leg and
foot problems if the cake is not removed.
On the other hand, large-particle litter, such as
wood chips or coarse straw, does not absorb
moisture very well and can also lead to foot/breast
problems. Find the middle ground for best effect.
The litter must be 10-13 cm (4-5 in) deep from the
start if the hens stay in the rearing house:
the height of a fist. If the hens are moved during
the grow-out phase, the litter must be at least
5 cm (2 in) thick in the new house. Where underfloor heating is being used, litter depth can be
reduced to 3 cm (1 in).
++very positive, + positive, +/- average, -negative, --very negative
Straw
Pinewood shavings
Rice hulls
Wood pellets
6. L itt e r m a n a g e m e n t
Pinewood shavings ++
+
+/-
Sawdust
++
--
Risk of crop blockage, gizzard
impaction, respiratory disease
Sawdust pellets
++
-
Exceptional hygienic status, but
dusty when pellets break
Chopped canola
straw
++
++
+/-
Chopped wheat
straw
++
++
+/-
Chopped flax
+
-
+/-
Rice hulls
+
++
+/-
Sunflower hulls
-
++
The sharp edges can damage
the skin and cause wounds and
infection
Ground corncobs
maize chaff
+/-
++
Good for intestinal health on
account of acidity level
Peat
++
--
Reduces footpad lesions
Alfalfa
--
+
Positive effect of raw fibers on
intestinal health
Sand
+/-
-
While it improves gizzard
function it increases the risk of
crop blockage, and pathogen
contamination
Hardwood
shavings
+
+/-
Possible contamination, higher
risk of mold
Peanut Hulls
+/-
-
Possible contamination, higher
risk of mold, more expensive
outside the production regions
81
Wood shavings
The moisture of your wood shavings should never
exceed 12%. Control it on arrival, otherwise, under
hot brooding house conditions, it will get moldy,
especially inside the plastic packages.
Avoid sawdust or wood shavings made from waste
wood (old furniture or preserved wood): the residual chemicals contained in them can be poisonous both to the birds and humans.
The thickness of wood shavings determines the absorption capacity. It should
not be thicker than 3 microns.
Sieving is another commonly used quality assessment technique. Wood shavings can be considered acceptable for brooding poults if they contain less
than 10% of fines (< 1 mm).
Sawdust is not a good litter material because poults are
more likely to eat it and this may lead to crop and gizzard
impaction.
LOOK-THINK-ACT
What is this man doing?
There is an easy test for dustiness: take a handful of wood shavings and throw them into the air. Watch them fall. The greater the
amount of fine material present, the longer it will take the cloud of
dust to settle down.
82
Turke y S i gnal s
Straw
Straw is abundant in many areas and cheap. The
absorbency of straw can be increased if it is spliced
and chopped into pieces of around five centimeters. A straw chopper can be used in the house,
but this would create too much dust. So, it is preferable to distribute the pre-chopped straw manually. Good quality short chopped straw provides
similar advantages to wood shavings, but with the
additional benefit of providing a very stable grip
for the young poults. This is particularly important
for exhausted poults post-delivery. Straw from the
spring crops absorbs moisture better compared to
winter crops. Barley and rye straw have superior
absorption than wheat straw.
After bailing, transport the straw directly to the
storage area and store it for at least four weeks
before use to allow for natural inactivation of most
pathogens. Transport the bails in covered trucks
or trailers – protecting them from rain, disease
vectors and contamination by dust and mud from
the wheels. Keep the straw dry and protected from
birds and rodents since there are often still some
grains left within it that will attract animals. Use
bait stations inside and outside the storage, every
5 meters. Use protective nets/mesh to shield it
from the birds.
Straw with a good moisture content: 10%. Never bale straw until its moisture content is below 12%. Avoid collecting straw from riversides, in the evening/morning
hours (dew), after rainstorms, or any other time when the air moisture is high.
Poults grown on straw have fewer losses due to flip-overs, reducing early
deaths. The grip on the straw is much better than on wood shavings.
Wood pellets fall apart after a few days. The material then becomes fine and
dusty. So not always the best litter material.
6. L itt e r m a n a g e m e n t
83
Litter quality
Once litter gets too wet, it is unlikely you’ll get it
dry again inside the humid house environment, so
be proactive! Check the litter at different points in
the house during your daily inspections so that you
can intervene in time. Stir the litter up with your
hands or feet as you go and check the consistency
and the floor underneath. The litter should always
be dry and slightly loose. It should not stick to
your hands or boots. Conduct (at least) a weekly
walkthrough of the turkey house looking specifically
at the quality of the litter in different parts of the
house. You often find poor quality litter in places
with a higher light intensity. Turkeys are more active
there and defecate more in that area, causing the
litter to become wet and compacted. Wet areas
are not just cold; poults will also avoid them. This
causes overcrowding in other places, creating additional litter problems there as well.
Top 10 Causes of wet litter
1. Inadequate initial litter depth or poor choice of
litter material. Also inadequate preheating.
2. Excessive stock density or birds clustering in
smaller portions of the house.
3. Poor water management — depth of water in
drinkers, height of the drinkers themselves and
excessive water spillage.
4. Poorly maintained (leaky) drinking water systems, drinking nipple corrosion due to the use
of aggressive chemicals (acids).
5. Moisture absorbed from loose droppings (containing a lot of water).
6. Improper temperature and humidity balance,
inadequate air turnover and movement across
the turkey house.
7. Improper ventilation or inadequate heating.
8. Inadequate or uneven air movement in the
turkey house: cold air settling too quickly, or
damp air not being removed effectively.
9. Too high mineral or salt content in the drinking water and/or feed causes birds to drink
more, which automatically leads to wetter
litter.
10. Insufficient litter turning and general inattention to the litter.
Very bad litter quality. If you put you boot in the litter and
you leave a distinctive footprint in the litter, it is probably
beyond repair.
84
A problem occurred even before the birds touched the
drinker. The young poults avoid this area. If left unnoticed for
a longer period (e.g. overnight) it might affect large areas,
causing sickness and mortality of birds until the very end of
the cycle.
The spot in the back is clearly a leaking nipple. The wet
spots in the front could be spillage. Whatever the cause
this is a serious problem if left unchecked.
Turke y S i gnal s
Litter management
Litter management is important to prevent the
litter from becoming wet and caked, especially in
the first week of life! The objective is to maintain
clean and dry feet by adopting the following measures:
1. Work litter just before ‘caking’ develops
• Remove ‘caked litter’.
• Stir to break up smaller clumps and promote
drying.
• Add dry litter or rake dry litter over wet areas
as needed.
• Till litter: if only the top is caked, tilling can
bring dry material to the surface and allow
more air space for drying, however, excessive
tilling may increase litter eating problems and
ammonia release.
• Add fresh litter as required, especially around
drinker and feeder lines. Don’t let the birds go
short, or your problems will increase.
2. Add heat
• Adding heat increases the moisture carrying
capacity of the air (a 10°C/18°F increase, doubles moisture carrying capacity).
• At 6-10 weeks of age, moisture in the droppings and exhaled air exceeds the heat given
off by the turkey. The net result is wet litter. Additional heat is needed to be able to
‘absorb’ moisture so it can be removed by your
ventilation system.
• Over 13 weeks of age, the moisture in droppings and exhaled air is less than the heat
given off by the turkey. The result is the exact
opposite problem, and you may end up with
dry and dusty house conditions. Control this
situation with ventilation, lower temperatures
and use of ‘foggers’ (adding moisture).
4. Reduce water spillage
• Keep drinker heights even with the backs of
the turkeys. Adjust frequently.
• For the first 14 days, keep water levels at the
top of the bell drinkers’ lip. After 14 days,
water depth should be reduced to 10-12 mm
(half inch) as your birds learn to access the
resource.
• Clean and disinfect bell drinkers daily.
• Move bell drinkers and feeders every other day
to prevent wet areas from forming ‘donuts’.
Have at least three locations to which drinkers
can be moved. Rake the litter in the area you
have moved the drinker from.
In areas where the litter is very bad, you can top the wet material with new
litter. Long straw could be useful since it creates a kind of mat on top of the
wet litter. Fine material will absorb the moisture very quickly and will then be
only adding to the problem.
3. Adjust ventilation
• Adequate and even air movement in the house
aids in removing moisture and equalizes temperature.
• Proper air turnover removes moisture, dust
and ammonia, resulting in good air quality.
Litter tilling is a time consuming activity. A modern fully automatic tiller for litter
does this autonomously.
6. L itt e r m a n a g e m e n t
85
Litter management during rearing
Maintenance of litter quality is important, ensuring
that it remains friable rather than becoming wet or
solidified. At its worst, wet litter containing a high
proportion of feces can become highly alkaline and
cause hock-burn and footpad lesions. Footpads are
a very good indicator of proper litter management.
Check them regularly and adjust litter management
as required, promptly. This is a particular problem
for densely stocked poults near the end of their
housing period, as they produce large amounts of
feces and spend much more time sitting or lying.
If litter is kept dry though, by correct stocking and
ventilation, bacterial breakdown of feces occurs
and these problems can be mitigated. If regular
tilling or litter management is not done properly or
when there are other problems with the litter, additional measures will have to be taken.
Till the litter, starting from the first affected area around the nipple drinking lines or/and bell-type drinkers. Then around the
feeders, where the birds defecate most.
A small cultivator is a handy tool to ease the litter tilling
process.
86
When there is no dry litter left on the floor due to high air
humidity, diarrhea, increased water consumption and caking, you should start adding fresh litter on the top of the old.
Don’t till caked litter: there’s more molding and ammonia underneath. Put a fresh layer on the top and consider what you
might do to limit this problem in the future.
Turke y S i gnal s
Litter management in grow-out
When selecting litter material for use in the growout phase, consider your goals and material cost:
common materials include dry straw, wood shavings or grain hulls.
The litter deteriorates during the long grow-out
period if not properly maintained. Among other
possible reasons are, high relative humidity of the
air in combination with cold outside temperature,
intestinal disorders and increased water consumption due to nutritional imbalances.
You should not be able to hear the turkeys walk
around the turkey house. Heavy males especially,
exert a lot of pressure per square centimeter when
they walk. With sufficient litter depth the weight
is spread over the footpad, and they walk quietly.
If there is too little litter, then all pressure centers
on a small part of the footpad, which can result in
footpad damage; in this case you will be able to
hear your birds walking around the turkey house.
In order to maintain the litter quality make sure
the water level in the bell drinkers is not too high.
Otherwise the turkeys will spoil a lot of water and
the places around the drinker will be hard and wet.
Rotary will not work to improve the litter quality
in that case. When the water/feed ratio is too high,
make sure you solve the problem first by changing the feed, medication or adding acids into the
water. Otherwise all the hard work will be for nothing, and the new shavings quickly spoiled.
This litter is too dry and dusty.
6. L itt e r m a n a g e m e n t
Keep the litter in good condition by tilling with a rotary harrow weekly. This
works as long as you are bringing up clean, dry litter from the bottom to the
top. If the litter you’re turning up is declining in quality then it might be time to
spread some fresh material.
Mechanical litter distribution is common on turkey farms. It helps to cover large
areas of turkey house floor with chopped straw and saves a lot of labor.
When a handful of litter is squeezed, the ball should begin to break up when released
(photo right). If the litter is too wet, it remains balled up.
87
CHAPTER 7
Feed and water
Efficient meat production from turkeys depends on a constant supply of high-quality feed that is balanced
in nutrients, amino acids, and minerals. It is also essential to have good quality water. From day-old up to
slaughter age the specific feed requirements of turkey flocks must be met to reach the genetic potential of
the birds and stimulate the development of the gastrointestinal system.
Liebig’s law of the minimum
Liebig’s law: growth is not dictated by the total resources available,
but by the scarcest resource (limiting factor). If one of the resources is
not 100% available, then the other resources will not be used optimally
(waste) and the maximum genetic growth potential not be reached.
Any nutrient can become limiting: amino acids, minerals, vitamins,
trace elements. The challenge is to meet the requirements of the bird.
All resources are available
in sufficient amounts, but
production (= water) level
will not exceed the level that
is determined by the limiting
resources (= shortest stave).
88
Phase feeding
The nutrient requirements of the birds change
throughout the growth period. Therefore, most
turkey flocks eat 4-7 different diets during the production period. It is even possible to have up to 20
feeding phases when diet transitions are made in a
controlled way. The more transitions there are, the
easier it is to match the feed to the birds’ needs,
but sudden changes in feed composition can disturb the gut flora (microbiota) and upset the birds.
In addition, the flavor or the feed changes can
affect feed intake. The transition between two different feeds must be gradual to minimize the stress
on the gastrointestinal system and avoid digestive
problems. Ideally they should be supplemented
with a short course of anti-stress vitamin additives.
Turke y S i gnal s
Adjusting the feeding program
To meet the birds changing feed requirements
farmers often provide different nutritional values and pellet types throughout the various feed
phases. Feeding programs are a starting point, but
on top of that a thorough performance analysis
is necessary to adjust the nutrient density of the
feeds (protein, energy, minerals) as well as the
feed phase duration.
The first measurement should be the growth
curve. Automatic weighing systems are available
to monitor weight on a daily basis. A group of the
turkeys can be weighed by hand (at least 25 birds
per group). Another important consideration point
is the slaughterhouse report regarding the carcass
and breast meat yield, fat and protein content of
the carcass, and liver condition.
Excessive abdominal fat deposition and fatty livers
can be a signal of an excessive metabolic energy
(ME) in the finisher feed. However, waiting for the
slaughter results to evaluate your feeding strategy
for the previous five months can be unacceptably
misleading. Therefore, daily monitoring of feed
consumption and growth curve is required for successful turkey production and pre-emptive action.
Starter (0-28 days)
•
•
•
•
•
Crumb or mini-pellet (2.0-2.2 mm/0.08-0.09 in) gives better feed
intake and end weight
Optimal development of organs, bones and muscles
High in protein, vitamins and minerals for maximum growth during
this very critical period
Add no whole wheat
Expensive per ton, but not per turkey because of the small
quantity eaten
Micro pellet 2.2 mm (0.09 in)
Crumb
Grower (29-70 days)
•
•
•
•
Pellets (3.0-3.5 mm/0.12-0.14 in diameter)
Gradually decrease protein content and increase energy
Feed structure aimed at maximum intake
Start and gradually increase wheat addition 5-15-20%
Example of a 6-phase feeding program
Phase
Age (days)
F
M
Sexes in one house
(intermediate: F+M)
1
0-28
0-28
0-28
2
29-42
29-42
29-42
3
43-56
43-63
43-60
4
57-70
64-84
61-77
5
71-98
85-112
78-112
6
99-105
113-140
113-140
Standard feed phasing recommendations for heavy
breeds can be used with separated males and females.
If you have a mixed flock, intermediate phasing can be
applied.
Finisher (71-slaughter)
•
•
•
•
•
Pellets (3.5-4.0 mm/0.14-0.16 in diameter)
Continue to reduce protein and increase energy
Maximum wheat addition 30-50%
Metabolic conversion of protein to fat results in poorer feed conversion, so it is important to give enough energy in this phase
Highest feed costs due to high intake during this period
Non-medicated finisher feed
Comparison of pellets 3.0 vs 4.0 mm (0.12 vs 0.16 in).
7. F ee d a n d w a t e r
Feed without medicines or anticoccidials must be given at the end
right up to slaughter. Some anticoccidials have a withdrawal time of
0 days so they may be used in non-medicated finisher feed.
89
Transition from crumb to pellet
During a turkey’s life the need for protein falls and the requirement for energy
increases. In nature you see that young birds are mainly fed worms (protein)
and gradually learn how to eat grain (energy). To meet these changing requirements, you work in phases of various nutritional values and pellet types.
If the pellets are too long or too hard, poults won’t be able to swallow
them, and their feed intake will be reduced.
In the first 24-72 hours it is very important to get
the poults to consume as much feed as possible.
Early management in terms of feed presentation,
lighting, easy access to drinking water and house
temperature must encourage the birds to eat. The
feed needs to be the correct size and consistency:
if it is too fine and dusty, the poults may not be
able to select enough particles and won’t consume
enough, if however, the particles are too large or
too hard the poults won’t be able to swallow them.
The transition from crumbled to pelleted feed is
critical. Birds may not eat if pellets are too large
or too long. If feed intake is reduced for 12 to 24
hours birds can lose up to a day’s growth and it
may affect gut health over the long term. Changing
from feed crumbles to pellets at the same time as
the move to the finisher house can stress birds
and reduce feed consumption. Therefore, it is best
to wait for a few days after moving birds before
changing feed presentation.
Even short periods of decreased feed consumption
due to disease or mechanical problems can result
in decreased weight gain and increased growing
times. Long feeding interruption periods lead to
significant stress visible as diarrhea, increased
incidence of skin scratches (birds piling around
the feeders), pendulous crops because of binge
feeding and higher losses due to culling.
Pendulous Crop
The crop is normally positioned in the wishbone cavity and is attached to the side and back of the neck. If the connective tissues can’t
hold the crop in place, the crop drops. Turkeys tend to overeat after a prolonged period of starvation, which is one of the causes of a
pendulous crop. Young birds with a mild pendulous crop condition may recover. Seriously affected birds seldom recover, and treatment
is ineffective. Nevertheless, some birds can survive till slaughter with good body weights. Genetics, as in all other defects, can play a
role in this condition as well.
Pendulous crop at 2 and 9 weeks.
90
Turke y S i gnal s
Feed structure
Pellets
Pellets are preferable to mash for a higher, more
balanced feed intake. Feeding pellets allow turkeys
to eat more, reduces waste, and assure that the
intended nutrients are consumed with each bite in
the correct proportion (no selection).
The pellets must be of good quality to prevent
them from falling apart into a powder before the
bird can eat them. In the bird’s crop, the particles
fall apart and turn into mash that passes into the
intestines. If particle size varies too much you
run the risk of selective feeding: the birds pick
the pellets they prefer out of the feed (the bigger
ones). Pellet size and quality do not tell you anything about the coarseness of the grind. Birds fed
poor quality pellets can have lower performance
compared to the birds fed coarsely ground mash,
while good quality pellets result in a significantly
increased growth. Pellet Durability Index (PDI)
depends on composition (wheat has better binding capacity than corn), grinding quality (fine or
coarse) and type of the mill (hammer or roller),
pelleting-die specifications (compression ratio)
and the pelleting regime (conditioning time,
steam quality, moisture, temperature, etc.). It is
possible to achieve a very good PDI of 95-98% for
wheat-based diets.
Good quality pellets with 5% fines.
Poor quality pellets with more than 50% fines.
Structure of the feed stimulates the development
of the gastrointestinal tract and good digestion.
A lack of structure because of too fine a grind
slows down intestinal peristalsis resulting in the
feed being less thoroughly mixed with the intestinal juices. When ground coarsely enough, mash
feed also stimulates the intestines, but pellets are
more easily ingested by the birds. Adding whole
grain wheat promotes stomach and gut development in older birds.
7. F ee d a n d w a t e r
91
Segregation: nutrients separate
Weak pellets create fines on the way from the feed
mill to the feeder. The nutrient content of fines
can differ from that of the pellets – this is known
as nutrient segregation.
Protein is lower in fines, while fat, minerals (Ca,
P, Zn) and vitamins tend to bind poorly to feed
and make up a greater proportion of the fines.
Not only will the nutrients separate in the silo but
segregation might also occur through selective
eating. The more aggressive birds can consume
the majority of the pellets and the latecomers will
be left with fines.
Fines separation can be particularly bad when
liquids such as fat and enzymes are applied
post-pelleting because a higher percentage will be
absorbed by the fines.
In general, the fine fraction is distributed first
(first feed distribution in the morning, first feeding pans). If you keep hens and toms in the same
house, it might happen that those sitting in the
front will always consume fines, and those at the
back will get the best quality pellets. You will recognize this in their growth curves very quickly.
Segregation in the silo can be prevented by using
a flat bottom silo where gravity (causing segregation) plays a less important role.
Segregation can take place in:
• Silo
• Hopper
• Feed lines
• Feed pans (selective eating, first turkeys get
the best pellets)
Medicine and feed segregation
Another serious risk of fines separation is related
to the use of medicines, e.g. coccidiostats, which
is important in the starter and grower feeds. Like
many other powdery ingredients of the premix
they may separate into the fine part of the feed.
Ionophores can be toxic for turkeys in high doses.
Birds consuming fines may wind up with a potentially harmful dose of the medication and birds
selectively consuming pellets may wind up with a
much smaller dose. Not only feed separation, but
also poor dosing and mixing at the feed mill can
lead to an uneven distribution of the coccidiostat
in the feeds. At the feed mill normally more than
one feed is produced, also for broiler chickens.
Be aware that even the smallest amounts of the
coccidiostats salinomycin and narasin can lead to
intoxication in turkeys (paralysis, mortality) whereas they are readily used in broilers. Clearly both
segregation and cross contamination of feeds can
be serious issues.
LOOK-THINK-ACT
A poult with leg paralysis from intoxication. The recommended dose
of for example monensin is 60-100 ppm and in case of serious feed
segregation the level in the feeder can be too high causing intoxication symptoms.
92
Courtesy of Borregaard LignoTech.
What is wrong with this poult?
Cross section of feed silo with a high concentration of
fines on the bottom. This means that at first the turkeys
get a totally different nutrient composition than when the
silo is almost empty.
Turke y S i gnal s
Turkey target weight and recovery
Birds that are somewhat below the target weight
at the end of the brooding period tend to go
through a rapid recovery phase in the grow-out
house where there is more space and greater
access to feed. But there is a risk that this growth
period results in a weakness in respiratory or
skeletal development in that portion of the flock.
Stress later in life can then result in increased late
mortality. Signals can be feather malformation,
growth retardation, leg weakness, an increased
number of cull birds and respiratory problems. If a
single flock is underperforming, conditions on the
farm should be reviewed. If more flocks throughout the farm are not meeting objectives then
an evaluation of the overall management, health
and nutritional programs is required. If the body
weights at the end of the rearing phase are far
below target (over 500 g/18 oz), birds will struggle
to compensate this during the grow-out period.
Adjust feed specifications
The feeding regimes are ‘dynamic systems’. This
means that the nutrient input should depend on
the health and performance status of the turkeys,
the weather, the price levels of feed components,
etc. A high energy feed leads, for example, to more
efficient feed conversion rate.
• Situation 1: Over-stressed intestine (diarrhea) use a nutrient-poor diet in phases 3-4 (‘dietary
feed’ with reduced specs by 5-10%), but not for
too long so that compensatory growth is still
possible!
• Situation 2: Weight specifications are not
achieved (e.g. heat stress) - use a nutrient-rich
diet phases 5-6 (‘booster feed’ with increased
specs by 5-10%).
7. F ee d a n d w a t e r
Keep a sample from every feed batch. If there are problems in flock performance, you can investigate whether the feed is the cause (e.g. toxic substances). Store the samples sealed in a cool, dark, and vermin-proof place for
at least three months.
Remember: Poults can only eat if they drink! Even with perfectly optimized
feed specification and physical form, the feed intake will not be optimal without clean, cool water available at all times!
93
Whole wheat
If the turkeys grow well, you could add whole
wheat to the pelleted feed. This is mainly an economic consideration: wheat is a relatively cheap
raw material. Wheat inclusion is recommended
from 3-5% in phase 2 and up to 40-50% by phase
6. There are two ways of adding whole wheat:
1. Directly (unground) through the pellet die.
2. Added on the top of the pelleted feed in the
feed mill or on the farm.
Grain can be added at fixed levels and the diets
are adjusted (controlled): the overall combination
of feed and grain matches the turkeys’ requirements.
When grain is added on top after feed formulation
- based on performance or weight of the turkeys the diet will be ‘diluted’. Dilution of the diet can
lead to suboptimal performance if not managed
carefully but can also result in a reduced cost of
gain. With less than 10% wheat added to the feed,
you can keep the formulation of the pellet unchanged. If you want to add more than that, you should
change the pelleted feed formulation to prevent
an imbalance of nutrients in the total ration.
Advantages and disadvantages of adding wheat
Advantages
Disadvantages
•
•
•
•
•
•
•
•
Adds structure to feed, especially if the pellets are made of
finely ground ingredients.
Stimulates gizzard activity, slows
down feed passage through the
gastrointestinal tract - Improved
gut health, lower FCR
Improves enzymatic activity of
pancreas and nutrients digestibility - better litter quality
Reduces feed cost
Increases the feed mill capacity
When added on-farm the levels
can be adjusted based on actual
performance levels
Can be used to reduce growth
in older toms if there are risks of
leg or heart problems
•
•
•
•
•
•
•
Salmonella can be present in
whole grain; the grain should
be treated with heat or organic
acids
On-farm grain stores must be
vermin/water proof
Blending systems are expensive,
involving capital expenditure
Wheat quality may vary and
should be tested routinely (e.g.
moisture, protein content and
mycotoxins)
Growth rate may be reduced
Breast meat may be reduced if
the diet is not balanced
Potential for contamination from
grain in the processing plant
Coccidiostat levels need to be
adjusted in the feed to account
for dilution
It is preferable to have two feed silos per turkey house
and a separate whole wheat silo next to them.
5-10% wheat inside the pellets.
94
20-30% wheat inside the pellets.
40-50% wheat mixed with pellets.
Turke y S i gnal s
Feed safety
The goal of any feeding system is to produce a
product that encourages bird health and growth,
while minimizing overall cost. However, ‘budget’
feeds can bring a whole new realm of problems
to light by adding unexpected components. Don’t
skimp ingredients or feed quality. Regular control
and a proper feed hygiene program can decrease
possible problems down the road.
Undesirable components:
• Weed seeds
• Undesirable additives (heavy metals, radionuclides, dioxins, etc.)
• Mycotoxins
• Microbial contamination
• Some coccidiostats are toxic for turkeys, or
cannot be used in combinations with some
antibiotics.
Molded corn, this can lead to mycotoxin problems.
Microbial contamination of feed
(EU regulation 183/2005)
Microorganism
Allowed level
(CFU/g)
Salmonellae, per 25g (0.88 oz)
0
Total enterobacteria count (TEC)
10
E.coli
10
Clostridia
1-10
Aspergillus flavus, parasiticus,
ochraceus, niger, fumigatus
300
Aspergillus, other
4,000
Fusarium
200
Penicillium
1,000
Yeast
500
Total number of molds
5,000
Newly harvested wheat grains sprouted due to the rainy harvest season.
This can be an important source of mycotoxins.
General guidelines for the permitted levels of different
microorganisms. Because Salmonellae are not allowed in
the feed, the number of enterobacteria preferably should
not exceed 100 CFU/g.
Weed seeds (black spots) in the whole wheat. These are
later found in the stomach.
7. F ee d a n d w a t e r
A stomach full of weed seeds.
95
Effect of mycotoxins
Mycotoxins
Mycotoxin
Effect
DON (Deoxynivalenol)
Reduction in intestinal wall villi height.
Slow intestinal response and recovery
after cocci infection.
Initial inflammation in the gastrointestinal tract.
T-2
Decreased glucose absorption.
Reduced coccidiostat effect.
OTA (Ochratoxin)
Increased lesions, mucosal damage and
more oocysts after cocci infection.
Aflatoxin and T2 combination
Increase Salmonella typhimurium CFU in
duodenal and cecal contents.
FUM (Fumonisin)
Altered barrier function of gut epithelium
Subclinical concentrations of
various mycotoxins
Increased susceptibility to infectious
diseases and reduced efficacy of
vaccines and other medication.
Tongue and gizzard necrosis due to T2 mycotoxicosis
Numerous mycotoxins are the products of molds.
Mycotoxins are damaging to poultry. When the
presence of mycotoxins in the feed is confirmed
by laboratory tests, prompt reaction is needed:
remove the toxic feed, identify the toxic ingredient
and withdraw it from the ration and start using
toxin binders to minimize the damage. Not all binders are effective against all types of mycotoxins;
the most dangerous one for turkeys (T-2) can
be successfully absorbed by just a few of them.
Combating mycotoxins in the feed can never be as
effective as prevention, like moisture level control
and using mold inhibitors (organic acids) prior to
the raw materials storage.
Quality control of feed ingredients is essential for
reducing mold and mycotoxin content in feed. This
is the responsibility of the feed mill.
Sources of mycotoxins
Molds grow on raw materials and feed in a high
moisture and high temperature environment. One
high risk factor is whole wheat, especially if the
grain is from an old harvest or freshly sprouted
wheat of the new season. If the wheat molded in
the field or is stored undried, without application
of mold inhibitors, mycotoxins accumulation in
the grains is almost guaranteed. Moisture content
of wheat may vary during the harvesting season. Good quality wheat ready for storage has a
moisture level below 14%. If it is harvested higher
than that, drying is necessary before storage or
inclusion in the ration.
The easiest way of checking mycotoxins in the feed and raw materials is an
express-testing system.
Enlarged kidneys and ureters blocked with liquid/solid urates can indicate a
mycotoxins intoxication. Check other symptoms and the feed for confirmation.
96
Always check the moisture level of your grains to prevent
molds overgrowth and mycotoxins accumulation. This is a
simple hand-held moisture meter.
Turke y S i gnal s
Mold/mycotoxin risks on-farm
Even a freshly produced feed made of good quality
and controlled ingredients can possess hazards for
the turkeys. Transportation and storage both come
with risks if best practices are not maintained.
Moldy feed must not be allowed to accumulate
anywhere in the feed transport system.
Clean transport vehicles along with grain handling
and storage equipment on a very thorough and
regular basis. Make sure the feed is protected
from moisture; in a wet and warm environment
mold grows very fast! Another important hazard is
Salmonella growth and accumulation in an improperly cleaned feed truck.
Accumulation of lumps of spoiled feed on the inside of the feed truck cistern (left). This can become a huge problem for
the poults. On the right: What an empty and regularly cleaned cistern should look like.
On the left accumulation of spoiled feed in the hopper, on the right lumps of spoiled feed from the feed silo.
Condensate drips from a poorly insulated ceiling can cause a lot of problems if spotted too late. Covering it with a piece of
cardboard is only a temporary solution: solve the initial condensation problem!
7. F ee d a n d w a t e r
97
Nutritional disorders
A number of poultry disorders may be caused
by nutritional deficiencies or imbalances. With
today’s well-formulated diets, nutritional problems
occur infrequently, but you must be on your guard.
It’s signals are seen in wet litter but also - for
example - in leg weakness.
Electrolytes
K+ (potassium), Na+ (sodium), and Cl- (chloride)
are almost 100% absorbed, irrespective of the
concentration in feed. If there is a high increase in
these electrolytes then an increased water intake
will be needed to eliminate the excess ions. This
results in a higher moisture content in the droppings. A moderate excess of sodium is not an
issue, but with potassium (for instance in soya)
you will see a clear impact.
Proteins
The level, source and quality of feed protein influence water intake and elimination. Increasing the
level of crude protein in the diet increases water
intake and the water:feed ratio. High protein levels
or an imbalanced amino acid profile will increase
uric acid excretion, which will stimulate water
excretion by the kidneys and consequently wet
litter.
Fats
Fats with poor digestibility are suspected of causing wet litter, most likely because undigested fecal
fat blocks the evaporation of water from the litter
by the formation of a greasy cap. Poor quality
dietary fat or rancid fat can lead to wet fecal droppings. The oily aspect of these wet feces might
indicate poor fat absorption due to poor fat quality. The use of acid oils such as soya or maize oils
can influence the gut microbiota since free fatty
acids can have an antibacterial effect leading to
disruption of the normal microbiota.
NSP
Cereals like rye, wheat and barley can contain
high levels of non-starch polysaccharides (NSPs),
especially shortly after harvest. Because of a less
efficient nutrient absorption due to NSPs, more
nutrients become available for the microbiota,
which enables bacterial populations to grow. This
can lead to bacterial enteritis and subsequent wet
droppings. This effect can be eliminated by using
NSP degrading enzymes.
Leg weaknesses
Leg weaknesses other than perosis may be caused
by vitamin deficiencies or by diseases such as
infectious synovitis. Another leg problem, crooked
toes, may be hereditary or due to faulty hatchery
or brooding conditions.
Rickets is caused by a deficiency of vitamin D3,
phosphorus, or calcium or by a calcium-phosphorus imbalance. Or that the available phosphorous
is hardly available to birds or phytase deficiency.
Rickets may occur in birds on range or when
grains are used along with complete feeds or
protein concentrates because the birds are not
getting enough calcium. Provide oyster shells to
these birds as an additional source of calcium.
Birds with rickets show weakness; stiff, swollen
joints; soft beaks; soft/rubbery leg bones; and
enlarged ribs.
Rickets due to vitamin D3/phosphorus/calcium disbalance,
malabsorption.
98
Turke y S i gnal s
Grit
Turkeys have no teeth to chew their feed.
Therefore, they need small stones to be added to
the feed, which help in the gizzard to grind feed
and possible pieces of eaten litter for digestion.
This grit is added in the feeding pan by hand
or provided in special grit feeders. Don’t run it
through the feeding system as the stones will
damage the equipment! Grit is likely to be of most
benefit when whole wheat is fed. With pelleted
feed made from fine ground ingredients the benefit is less, if seen at all.
Litter eating
Turkeys, being naturally curious, commonly
peck and test their environment; in some cases,
this can lead to an over-consumption of litter.
Birds consuming litter ingest a greater number
of potential pathogens while consuming fewer
nutrients and feed medications, resulting in
reduced weight gain and loss of uniformity.
Gizzards filled with litter can become impacted,
punctured and/or ulcerated. Litter eating can
be an abnormal bird behavior but is commonly
associated with enteritis. Identification and
elimination of the cause will reduce (but may not
eliminate) litter eating, as some birds will become
‘trained’ and continue to peck at the litter.
5 mm (0.20 in)
Stones are useful to help in digestion. Calcium carbonate sources such as
shell pieces are too soft to provide this benefit.
Size of stones depends on birds’ age
Age of turkeys
(weeks)
Stone size (mm, in)
2-5
2-3 (0.8-0.12)
6-10
3-4 (0.12-0.16)
11-14 (females)
5-6 (0.20-0.24)
15-18 (males)
6-8 (0.24-0.31)
2 weeks before
processing
Stop feeding stones, they
must not appear during
the slaughtering process!
Before using any kind of grit – disinfect it. e.g. acids or hypochlorite used for water
line sanitation. Rinse the grit thoroughly with clean water after the disinfection.
Birds are consuming as much or more litter than feed, resulting in 50% or
more litter in the gizzard contents. This stomach is compacted with straw
– a typical finding in poults that have starved.
7. F ee d a n d w a t e r
99
Water
Water is the most important feed ingredient!
Turkeys consume about twice as much water
as feed, so it is important to provide a clean,
healthy water supply. Water not only serves as
a vital nutrient but it also affects virtually every
physiological function in the body. The drinking
water should taste pleasant and be clear of any
hazardous substances or impurities. If the water
doesn’t taste good, turkeys won’t drink it and may
dehydrate and die. Even if the water quality is
improved it will be difficult to get them drinking
again. Water also serves as a solvent for medicines
and vaccines. When vaccinating via drinking water,
make sure the water is clean and cool and that the
water line is working properly. Water sanitation
should be turned off at least 24 hours prior to
drinking water vaccination.
Young poults are particularly sensitive to poor
water quality because their gut microbiota is still
developing. A hot brooding house (= rapid bacteria growth) and low water consumption (= low flowing rate) at this age are the ideal conditions for
bacterial biofilm development in water systems.
So there is twice the risk of issues.
Check the water:
1. In general, at the location of the meter (automatic)
2. Per drinking line: the height of the water gauge
(daily)
3. Per nipple (at least 2x/month)
Check your water pressure in the house by the height of
the water column in the middle and the end of the lines.
Measure the flowing rate on a regular basis.
High quality drinking water is important to maintain
good growth rates and good health in your flock. If you
wouldn’t drink it why should your flock?
The watering system with possibilities to mix various sanitizers. The large tank has an automatic mixer to prevent
sedimentation of the product.
100
A quick visual assessment could already reveal problems.
It should be colorless and clear (not opaque).
Turke y S i gnal s
Water quality characteristics
The microbial or bacterial test results are
expressed in Total Plate Count (TPC) of Aerobic
(oxygen loving) Bacteria as measured by CFU/
ml (Colony Forming Units/ml). These results do
not indicate whether the bacteria present are
harmful or harmless but it can tell you if the system is dirty and therefore at risk of the presence
of pathogenic bacteria. Test results greater than
1,000 CFU/ml means the water system should be
more thoroughly cleaned between flocks and a
daily water sanitation program implemented when
birds are present.
The acidity (pH) impacts the effectiveness of disinfectants such as chlorine. If water has a high pH
then it may be necessary to acidify it.
Turkeys are very tolerant of some minerals such
as calcium and sodium but very intolerant of iron
and manganese. Iron and manganese tend to give
water a bitter, metallic taste and iron also supports microbial growth such as pseudomonas or
E. coli. There are many cases of mineral contaminants that are not within desired levels, which
result in:
• Poor performance
• Equipment failure or damage
• Presence of harmful bacteria or biofilms
Iron results in a rusty brown to red colored residue, while manganese and sulfur can form black
colored residues. Natural sulfur in the water
should have a smell similar to a match head. If the
water smells like rotten eggs, then the culprit is
hydrogen sulfide. Hydrogen sulfide is a by-product
of sulfur loving bacteria.
Nitrates are colorless and odorless and the only
way to detect their presence is through testing. As
little as 10 ppm nitrate can impact performance
causing reduced growth rates and poor feed conversions.
Pseudomonas
Pseudomonas is a water-loving bacterium and may be passed through
contaminated water sources or exposure to infected birds. It can cause
a high mortality rate in young or immunosuppressed birds. Healthy
adult birds are not as likely to contract infection. Symptoms include
lameness; lack of co-ordination; swelling of the head, wattles, sinuses, hock joints or footpads: diarrhea; and cloudy, infected eyes. The
treatment is to immediately isolate or cull infected birds. This bacterium
is highly resistant to most antibiotics. It is crucial to identify the source
of contamination to prevent further infection. Once the water system is
colonized by Pseudomonas spp., a thorough cleaning and disinfection is absolutely necessary. Avoid dead ends, because this is usually
the place of colonization. Flushing the lines before filling waterers and
during the brooding phase may reduce the chances of infection.
Water quality parameters
Contaminant,
mineral or ion
Maximum
acceptable level
Bacteria
- Total Bacteria (TPC)
- Total Coliforms
- Fecal Coliforms
1,000 CFU/ml
50 CFU/ml
0 CFU/ml
pH
4-8
pH below 4 can be harmful to the drinker equipment by causing corrosion to metal components with long term exposure; soda ash or caustic soda injection will raise the pH.
pH above 8 impacts effectiveness of most water sanitizers; acid injection will be required.
ORP
650-750
millivolts
Oxidation-reduction potential (ORP) measures the effectiveness of the sanitation program.
Total Hardness
110 mg/l
Hardness causes calcifications which can reduce pipe volume and cause drinkers to be
harder for birds to trigger or to leak. Softeners can remove hardness up to a practical limit
of 1,700 ppm (mg/l). If the hardness is above 1,700 ppm or the sodium to hardness ratio is
greater than 33% then the sodium level will be high after softening and reverse osmosis may
be required.
7. F ee d a n d w a t e r
Comments
Total Bacteria is used as an indicator of system cleanliness. High numbers do not necessarily
mean the bacteria present are harmful but it does mean that the system is capable of
harboring pathogenic organisms. High bacteria levels can impact the taste of the water
resulting in its reduced consumption by birds.
101
Biofilm development
Huge biofilm taken from a drinking line.
Many products given via drinking water are a feeding ground for all kinds of bacteria and molds. A
slimy film consisting of bacteria, yeasts and molds
– the biofilm – quickly forms on the surfaces of the
water lines. The use of groundwater with organic
material increases the risk of biofilm formation.
So, before and after adding substances to drinking
water, make sure you flush the pipes thoroughly,
because biofilm also adversely impacts on antibiotic treatments or vaccinations given via the
drinking water. Flushing alone is not sufficient
against biofilms; chemical products are also
required. The film interferes with disinfectants as
well. Biofilms can also cause leaks in the drinking
system. Contributing factors leading to biofilm in
the water system:
• Dead ends
• Hanging pipes
• Oxygen
• Light
• High temperature
• Use of additives like vitamins/sugar
Biofilm, a conglomeration of
pathogens in the water pipe
1
2
Biofilm in a drinking line.
athogens attach themP
selves to a surface.
3
athogens stick to each
P
other by forming glue-like
compounds.
The biofilm grows.
4
articles of biofilm break off
P
and the pathogens spread
through the water pipe.
Drinkers can also be a source of infection. Dirty water collects and warms up,
forming an excellent feeding ground for bacteria.
102
Turke y S i gnal s
Water sanitation: key for flock health
Cleaning the water lines between flocks requires
a sound procedure, since many disinfectants are
toxic for the birds. Some of the most effective products which do not damage the drinker systems
are concentrated, stabilized hydrogen peroxides.
A peroxide cleaner is used as soon as the house is
depopulated in order to remove any biofilm, and
then repeating the process 24 to 48 hours before
restocking the house. But this is only half the battle. Even with a thorough cleaning, if a significant
number of bacteria, fungi or yeasts are still present, then the biofilm has the potential to return
completely in 2-3 days. Often a combination of
acids and chlorination is used for sanitation when
the birds are present, but use them with care! Do
not add chlorine when administering vaccines,
medications, or vitamins. Do not mix chlorine and
other products in the same stock solution.
Products to improve water quality must have a
dual effect: removing the biofilm and killing off
microorganisms. Chlorine based disinfectants do
not destroy biofilms. Furthermore, biofilms cause
rusting in metal pipes, which can be exacerbated
by chlorine. Products that are too aggressive (e.g.
peracetic acid) can actually damage the drinking
water system itself. Peracetic acid is also carcinogenic and affects the taste and smell of the drinking water, so the birds will drink less.
A low pH decreases the bacterial load, so acids are
often used in sanitation. Nevertheless, many of
the popular water additive products such as acids
and performance enhancers can create conditions
favorable for the growth of yeasts and molds resulting in a gooey slime that will clog drinkers and
generally create disaster in water systems.
How to clean water pipes between flocks
1.
2.
3.
4.
5.
Fill the pipe with disinfectant.
Touch every nipple to ensure that the disinfectant fills all of them.
Leave for 24 hours.
Check the insides of pipes and tanks.
Flush the pipe with high pressure, again flicking every nipple to
empty the disinfectant.
Agent
Effect
Ozone
Very effective against bacteria/viruses; reacts with iron and
manganese making them easy to remove; inactivates chlorine,
but effect is highly localized.
Ultraviolet
light
Less effective against viruses; only effective in the part of the
water pipe where the UV rays come into contact with the water.
Copper
sulfate
Binds copper ions to bacterial cell walls, causing the bacteria
to die. Risk: Copper will be accumulated in the liver if used
constantly.
Chlorine
Cheap but less effective with pH higher than 7 or in presence of
organic material. In this case, you can add acids to reduce the
pH (vinegar might do the trick). Sodium hypochlorite (bleach) is
a very common water sanitizer in turkey production.
Organic
acids
Bacteria inhibiting. After adding to drinking water, the pH
should drop to below 4.3 to prevent molds and yeasts from
growing in the drinking lines (pH should stay above 3.5 to
maintain water intake).
Hydrogen
peroxide
Cleans drinking lines efficiently, killing molds and bacteria and
dissolving the biofilm.
The influence of organic acids (pH) on the growth of bacteria.
pH
E. coli
Salmonella
Clostridium
6.4
++++
++++
++++
6.0
+++
+++
++++
5.8
++
++
++++
5.4
+
+
+++
5.0
-
+
++
4.5
-
-
+
4.0
-
-
-
Intensive usage of chlorination with acidifiers can lead to corroded nipples, causing multiple leakage spots in a turkey house. Don’t allow
high doses of disinfectant to stay in the pipes longer than 24 hours. Replace damaged nipples before the new cycle.
7. F ee d a n d w a t e r
103
Adding sanitizers
In a very simple set up, you need 2 buckets and
2 medicators, which will continuously dose acid
and sodium hypochlorite into the water line. To
use this system effectively you must first determine the dose of the compounds required and
monitor the results at the front and back of the
house to ensure that your birds are receiving water
that meets their requirements wherever they are
located. This is not a ‘set it and forget it’ system;
water quality should be monitored frequently and
rechecked seasonally when water components may
change (pH/ORP).
Flushing
After cleaning the pipes with chemical products,
clean water will flow through the pipes, but this
does not mean that it is totally decontaminated.
If you flush out ‘cleaned’ pipes (i.e. force-pumping water, and allowing the water pressure to rise
and fall), you will see that there’s still a lot of
dirt coming out of the pipes. The biofilm will not
be removed by cleaning with chemicals alone; a
force-flushing must also follow. Especially in the
first week it is advised to flush the water lines,
since the ambient temperature in the house is high
during this period, stimulating bacterial growth.
Besides, fresh drinking water increases the feed
consumption leading to a good start for the poults.
Flushing water lines is crucial for supplying poults with fresh, cool,
clean water. It can be done manually (top), or using a semiautomatic
(middle) or fully automatic on a programmable temperature/time sensor (bottom). However, with flushing consider very high water to feed
ratios during the first week – up to 6:1. Therefore, it is important to
measure the amount of water used for flushing to be able to monitor
the real consumption by poults.
104
Separate buckets for the acid (first) and the hypochlorite
(second) on the water pipe, entering the house. Don’t
forget to mark them accordingly to avoid mixing buckets
by mistake.
Turke y S i gnal s
Water quality testing
To get an accurate picture of the water quality it is
important to take samples as closely as possible
to the point where the turkeys drink. This not only
tells you about the quality of the water source,
it also gives you an idea about the status of the
pipes and nipple lines.
There are a few parameters to judge about quality
• pH: acidity of the water. A pH-value should not
be above 7. A bit acidic (below 7) is preferable.
• ORP: oxidation reduction potential. A high
ORP indicates a high capacity to sanitize water.
• RLU: Relative luminescence/light units, this is
an indication of the microbial contamination,
measured by a special instrument: a lumino­
meter.
The first test is one you can do yourself. Take two
glasses and fill one with water entering the house
and one at the end of the line. Check its smell,
color, taste and clarity. Collect water in clean, screw
top bottles, leave a window of one week and check
again. A laboratory test can give you very detailed
information on chemical (1x/year or when problems
occur) and biological (2x/year) characteristics.
Test strips for measuring pH is an easy and cheap way of
assessing water quality.
Measuring water line sanitation: ORP
An important piece of information about the
effectivity of the sanitization program is the ORP
value of the water (oxidation-reduction potential).
An ORP value in the range of 650 mV or greater
indicates good quality water that can be effectively
sanitized by as little as 2 to 4 ppm free chlorine.
A lower ORP value such as 250 mV indicates a
heavy organic load that will most likely overwhelm
chlorine’s ability to properly disinfect the water.
At an ORP value of 650 mV, any bacteria that
comes in touch with the water (e.g. through birds
drinking) are killed immediately avoiding their
spread within the flock through birds drinking
from the same, contaminated drinker.
Use information on pH, ORP, RLU and chlorine
levels to determine if the sanitation program is
effective and, moreover, to prevent equipment
damage by the overuse of chemicals.
The longer water stays in the pipes, the less chlorine
activity remains. ORP dropped down to 308 mV, RLU
219. This water is not safe anymore. Flush the lines,
check the chlorination/acidification regime.
Hand-held meters are low cost and are easy to carry. Check the hygienic status of you water lines just before the poults arrival: pH 6,
ORP 796 mV and 8 RLU confirm water lines are clean. T 28°C (82.4°F) – too hot, flushing is needed!
7. F ee d a n d w a t e r
105
CHAPTER 8
Brooding period
Brooding young turkey poults is the most important phase of raising turkeys. Turkey poults are kept in
an environment with supplementary heat for 4-6 weeks, depending on the regional climate. A high level
of husbandry management is required to encourage the poults to begin eating and drinking.
Temperature variation control also minimizes stress and helps to maintain the immunological competence of the very susceptible young poult.
Preparing for the new cycle
•
•
•
•
•
•
•
106
Ensure housing and equipment is cleaned
and disinfected.
Make sure equipment is working properly:
brooders, fans, generators, lights.
Ensure sufficient ventilation to maintain good
air quality, check inlets and outlets.
Evenly spread litter on the house floor:
in case of wood shavings 7 cm (3 in)
(summer) – 10 cm (4 in) (winter).
Place feeding and drinking equipment
appropriately evenly distributed, at a correct
height.
Appropriate preheating as required
(floor temp. 28-30°C/82-86°F).
Take the time to check for and block any drafts.
Between two cycles, you should get your brooding
house clean, warm and perform any necessary
maintenance. Based on the feedback from the previous cycle, you can take the opportunity to make
changes to the housing, lighting, feeding or vaccination schedules. The basic needs for a young
poult are fresh air, clean cool water, quality feed,
good litter and sufficient warmth. The goal of the
brooding period is to stimulate poult activity, eating and drinking. Supplemental drinkers and feeders are generally used during the first few weeks
to ensure that poults readily find these resources.
It is important to get poults started early on feed
and water. If they don’t find the feed and water
easily, starvation or dehydration will occur.
Turke y S i gnal s
Heaters/brooders
Since young poults are unable to maintain their
body temperature, a warm environment must be
provided. Brooder rings confine the poult areas
and provide them with sufficient heat, water and
feed during the first days of brooding. Set up the
brooding area about 48 hours before the poults
arrive. Rings should be at least 60 cm (2 ft) away
from the wall, with brooder guards of 30-45 cm
(1-1.5 ft) high.
Brooder rings are usually made from corrugated cardboard and are generally removed by the
end of the first week. For warm-weather brooding
or houses in which drafts are not a problem, the
brooder guard can be made from poultry wire
secured to frames. When using reusable brooder
guards be sure of your sanitation procedures; they
come into contact with your poults at their most
vulnerable time! Brooders should be activated at
least 24 hours prior to poult arrival to warm the
room and shavings. A minimum of 12 hours prior
to poult arrival, set stoves to reach starting target temperature. Stoves (3.5–5.0 kW) are placed
approx. 90-100 cm (3 ft) above the shavings to
reach a ‘hot spot’ target of 35-38°C (95-100°F). At
the inside edges of the brooder guard, 25°C (77°F)
(room temperature) is sufficient. The poults tell
you, whether it´s too hot or too cold! You want to
see them congregate loosely under the stove! Not
piled in the center, nor at the edges. Set temperatures according to the poults’ behavior.
Brooder rings
Single brooder rings should be 4-5 m (13-16 ft) in
diameter. In case of a single brooder, after three
days combine rings to include up to four brooders.
Multi-heater brooder rings are larger, but should
include no more than four brooder heaters. Place
a maximum of 350 toms or 400 hens per stove.
Whole house brooding
Whole house brooding needs much higher room
temperatures (~ 35°C/95°F) because you don’t
use brooder stoves. With local stoves the poults
search out their own comfort zone, but in case of
whole house brooding the temperature should
be the same everywhere (difference in the house
should not exceed 1°C/2°F. The main risk comes
from having too many poults per section; in this
situation a pile-up can be disastrous.
8. B ro o d i n g p e r i o d
LOOK-THINK-ACT
Why would you make round corners?
Turkeys have a tendency to pile up in corners and smother each
other in this way. With rounded corners piling is basically prevented.
A classical brooding ring for 400-600 poults. The risk is if the brooder breaks
– poults will get cold. So it’s preferable to have 2 brooders per ring. Another
problem is the high levels of toxic carbon monoxide (CO) – as a by-product of
combustion in gas-fired heaters.
A good whole house brooding pen: plenty of litter, the right temperature, feed
and fresh drinking water available on arrival. The house is separated into a few
sections. Fill the feeders and waterers and have everything ready so the poults
can be removed from the poult boxes and placed as soon as they arrive.
107
Floor temperature
The poults will be living continuously on the floor,
so it is very important to make sure it is warm
enough. The air in the house warms up more quickly than the floor. Only measuring the air temperature in the house is no guarantee that the floor will
be the right temperature. Feel the floor with your
hand; an infrared thermometer can be a useful tool,
but don’t just rely on technology.
A cold wet floor in a brooding house is a guarantee
of unspecific enteritis, increased mortality and a
non-uniform flock from the first week.
Brooding area ready for the poults: uniform high temperature (red). Notice that the only cool spots are the additional drinkers with fresh cool water (blue).
Literally put yourself in the place of a poult: if the environment is comfortable for you, that is a good sign. Critically
important is the absence of any draft at bird level (air
velocity < 0.1 m/sec (0.22 mph)).
The higher the temperature of the floor, the easier it will be to get the flock started without problems.
Never put litter on the wet floor, since a wet floor is always cold.
108
Turke y S i gnal s
Preparing the bedding/litter
The floor and litter material must have time to
warm up. A cool floor and litter can act as a heat
sink that pulls warmth from the poults even
though the brooder is operating properly. Some
producers cover the litter with paper for 3 to 7
days after the poults arrival to prevent them from
eating the litter. If the litter is covered, use rough
paper to prevent foot and leg problems. Most producers don’t cover the litter. Distribute the litter
very evenly over the floor, and make sure it’s dry
and free of mold and dust. Very coarse litter can
also contribute to leg disorders, while fine materials can be too dusty. Check the litter moisture on
arrival to the brooding house. Do not accept bags
or bails with moisture levels above 10%.
LOOK-THINK-ACT
What went wrong with this litter?
Molded litter material. At high brooding temperature, wet shavings will
already become moldy inside the plastic bags. Do not use such litter
under any circumstances.
Evenly distribute the litter over the floor surface.
For the poults’ sake, remove bags of shavings
to a more suitable storage space; otherwise you
will find a few dead poults per day in each plastic bag they can access! Do not leave anything
extraneous in the house for any reason, as the
curiosity of your flock will cost you!
Check and replace leaking nipples BEFORE you distribute the litter in the
turkey house.
8. B ro o d i n g p e r i o d
109
110
Feeder and drinker requirements
Feed availability
It is important that poults have access to feed and
water as quickly as possible. Time spent making sure
all of the poults have been introduced to water helps
ensure a successful start. When distributing the
feeding and drinking facilities in the turkey house, it
should be ensured that the birds are no more than
3 m (10 ft) away from a feeding point, wherever they
are in the house. The individual drinkers should, in
turn, not be further than 3 m (10 ft) from the next
feeding point.
Poults require a very high-protein diet in the early
stages and can be slow to begin feeding. This problem can be reduced by positioning feeders and
drinkers under bright light. It is helpful if the water
sparkles as this attracts the poults. As always be
vigilant! Check bins, augers, hoppers, etc. regularly
for moldy feed. If using brooder rings, position
feeders at least 30 cm (12 in) from the edge of
heater and brooder guards. Ensure that the lip of
the feed pan is even with the height of the average
birds’ back. As an initial consideration make sure
that there is 40 g (1.5 oz) of starter feed per poult,
close to the drinking lines. Feed can be laid out on
paper in this area to ensure that the poults find
the feed easier and quicker: the noise made when
walking and pecking on it attracts the poults. The
quicker they take in feed and water, the lower the
mortality and the better population uniformity and
growth will be in their first week.
Type of equipment
Live weight
per unit, kg/st
Round feeders
250/40
Round drinkers
(25-50 cm/10-20 in Ø)
350/55
Nipple/cup drinkers
150/24
At the start there are a lot of drinkers and feeders. Ensure
2 feeding and 2 drinking points per 100 poults, 50% of
which is supplementary equipment which will be removed
when the poults become more confident in the house.
Poult paper placed along the drinking lines is a good solution to give the poults more feeding space in the first days.
It also reduces the number of starved poults during this
period. Removal of supplementary feeders can begin on
day 7.
Utilize supplemental feeders and drinkers as necessary.
Egg/fruit trays may also be used. Keep feed clean and
free from shavings, debris and manure.
Once the birds arrive have cones adjusted to flood feed
level and provide a minimum of one feed pan per 50
toms and 60 hens.
Turke y S i gnal s
Drinkers
Water drinkers are placed around and between the
heat source. Usually 2 to 3 round bell-type drinkers are used per 2-heater ring. Additional vacuum
drinkers that require manual filling are used during
the first few days to supplement the automatic
drinkers. Bell-drinkers are believed to be the best
water source for turkeys from a day old to their
slaughter, but they carry dangers, and require more
attention and work; despite the risks there is no
doubt that they are easier for poults to start drinking from. Water intake depends on feed intake,
feed composition, house temperature, and age:
• Normally: 1.6 – 2 x amount of feed
• High temperatures: 3 – 4 x amount of feed
• High salt content: 4 x amount of feed or more
It is not just the air that needs to be at the right
temperature, but the floor in particular and the
equipment: the slats, the paper, the feeding system and the drinking water. Water that is too cold
(< 20°C/68°F) leads to a drop in body temperature,
which day old poults cannot regulate.
Pros and cons of drinking water systems
System
Pros
Cons
Bell drinkers
+ Water is readily available
+ Water level and suspension height easy to
regulate
- Open system, not
always fresh, more
chance of contamination
- Spills, wet litter
Pendulum
drinkers (nipples)
+ Closed system, water
always fresh
+ Very little spillage
+ Lots of room to walk
around
- High investment costs
- Water delivery harder to
control
The plastic mesh helps in preventing litter from fouling
the waterers, keeps the poults out of the wet litter that
frequently surrounds the waterers, and keeps the litter in
better condition. It should also reduce footpad dermatitis
which has its origins at a very early age. Regularly change
the position of the waterers.
It’s good to have both bell and nipple (pendulum) drinkers
in brooding, but poults prefer to drink from the bell drinkers.
So when removing them, do this gradually, letting the poults
get used to the main type of drinkers. If you do it all at once,
there is a possibility of dehydration mortalities.
8. B ro o d i n g p e r i o d
A piece of plastic/rubber hose or a special protective ring prevents
the poults from jumping into the bell drinkers, contaminating them with
manure and litter, and possibly drowning. Keep them until the poults are
3-5 days old. Keep the water level at maximum from a day old.
111
Pendulum drinkers with float ball
1. A
t low water levels, the float ball
pushes the pendulum, allowing
water to flow into the cup.
2. With enough water in the cup,
the ball will float: the pendulum
returns to its normal position.
When using pendulum drinkers, a float ball helps
the very young poults since the poults are not
strong and experienced enough to move the pendulum. The drinker normally operates when the birds
move the pendulum to the side with their heads as
they drink from the cup, triggering the nipple valve
to open. When the birds stop drinking, the pendulum moves back to its original position, closing the
valve and stopping the water flow. If water remains
in the cup, the birds are able to drink directly from
the cup without activating the pendulum, which
prevents the cup from overflowing. As for every
drinker, the correct height adjustment is important
for optimum water consumption.
LOOK-THINK-ACT
Why is there more spillage from the left drinker?
The bottom has a shiny surface to attract the birds.
The ball in pendulum drinker helps to fill the cup and assist
the poults in finding the visible water surface at the beginning.
There is still a floating ball in the left drinker and not in the drinker
on the right. Remove the balls from the cups when the poults get
older (7-10 days). If you leave the balls in too long your poults will
start spilling water and throwing the balls out of the cups. But don’t
take them out too early: the poults will fail to push the pendulum and
dehydration mortalities will skyrocket. Don’t remove all the balls at the
same time, but gradually, so the poults can get used to the changing
situation.
112
Working with the pendulum drinker: at low water levels, the
birds move the pendulum to the side.
Turke y S i gnal s
Poult transport
Unless it has been disinfected on site, the hatchery
poult delivery vehicle should not enter the brooding farm. The driver and other personnel must
meet biosecurity requirements to enter the brooding farm. Temperature in the poult truck should be
between 24-27°C (75-81°F). During a very cold period it can be 1-2°C (2-4°F) higher. It’s always good
to have extra data loggers to make sure poults
have the right temperature and they are not losing
too much energy on the way to the farm.
Check poults on arrival
One of the most important factors in brooding is
to start off with good quality poults. All poults are
not equal in their health, vitality, or general livability. Good quality poults are easier to raise.
Poor quality poults have decreased chances for
survival and may experience difficulties for their
entire rearing period or require special attention.
On arrival, pick up poults from various trays for a
proper assessment so you can adapt your management to the quality of the new flock.
Poult temperature
Rectal temperature measurements are not often
taken but they are the best method for assessing
body temperature. For an accurate reading, make
sure the thermometer is inserted two centimeters
deep in the rectum. You can use an ear thermometer on the vent, but this is less accurate. The
optimal measured body temperature for a poult is
39.5-40°C (103-104°F). 10% of poults that have a
body temperature of 37°C (99°F) upon delivery will
die shortly thereafter. Put any boxes that cannot be
handled immediately in a separate room at a temperature of 22-23°C (72-73°F), not in the brooder
house if it is much warmer (above 30°C/86°F).
On the poults arrival to the farm take the electronic printout from the temperature loggers or the loggers out from
the poult boxes.
Weigh 5% of the day-old poults for a good idea of their
weight and uniformity. Take these birds randomly from various trays for an accurate estimate. Count the poults in at
least 5 trays to determine the exact number you received.
The correct rectal temperature of 40°C (104°F).
This temperature too low. If it occurs with more of the
poults, increase the brooding temperature a bit to warm
them up.
8. B ro o d i n g p e r i o d
113
Check list for day-old poults
Culling day-old poults
Check
Right
Wrong
Reflex
Lay a poult on its back. It
should stand up within 3
seconds
Poult takes more than
3 seconds to stand up:
poult is listless
Eyes
Clean, round and shiny
(Semi) closed, dull
Navel
Navel should be closed and Bumpy: remnants of
clean
yolk; open navel; feathers
smeared with albumen
Feet
Feet should be a normal
color and not swollen. Feel
warmer than your cheek
Red hocks, swollen
hocks, malformations,
deformed toes, cold
Beak
Beak clean with closed
nostrils
Red spots on beak; dirty
nostrils; malformations
Yolk sac
Belly soft and malleable
Belly hard and skin taut
Down
Should be dry and shiny
Down wet and tacky
Uniformity
All poults the same size
More than 20% of poults
are 20% heavier or lighter
than average
Vent temperature Should be approx.
40°C (104°F)
The culling criteria for day old poults is similar to
that used at hatch: weak, injured, poorly healed
navels, innate defects (additional toes, beak deformities, blindness, open skull), transport traumas
etc. Considering the speed of day-old poults
processing in the hatchery, it is very difficult to
cull 100% of poor quality poults, besides some
problems will appear after the transportation to
the turkey house. Thus, it is crucial to identify and
remove them during the placement and within the
first 24 hours. Sometimes it takes 1-2 more days
to reveal all non-vital poults.
Above 41°C (106°F):
too high, below 38°C
(100°F): too low
LOOK-THINK-ACT
A fit and healthy day-old poult gets on its feet again
within three seconds, even when you put it on its back.
But you could help them a bit...
What happened with this poult?
Small poults’ feet must never feel cold when you feel
them against your cheek, your lips or the back of your
hand. Cold feet are a sign that the heat from the birds is
being sucked away via the floor (conduction).
The poult’s leg got stuck in the box and is irreparably damaged.
This happens more often in cardboard boxes with sections. Ask the
hatcher to be careful with loading the day-old poults.
114
This poult with splayed legs should be culled.
Turke y S i gnal s
Poult placement
Due to treatments in the hatchery and their transportation, the poults will be very tired by the time they
arrive at the farm. After emptying the boxes, switch
off the lights and leave the poults alone for 5 minutes. No personnel movement in the turkey house
is allowed at this time. Following this period, switch
on the light (80-100 lux/7-10 fc) and again leave the
house for at least 30-40 minutes, but up to 2 hours.
Let them get accustomed to the new environment.
Only then you can start working with the flock; select
the weak poults, pick up the flip-overs, place them
into recovery pens or cull them. After this time, further adjustment of the ventilation, drinkers, feeders
and heater height and temperature may be necessary. You might have different preferences, but the
basic principles outlined above should be followed.
After visual assessment move the trolleys from the truck directly into the house as soon as possible, especially in cold temperatures. According to the sex of the poults and production cycle, place the trolleys along the house in front of the rings.
Put the boxes along the feeding line/paper and let the
birds calm down for 5 minutes with the lids on. Never
stack boxes on each other.
It can be practical to vaccinate/spray probiotics while the
poults are still in the boxes.
After 5 minutes at low light intensity (20 lux/2 fc) carefully
empty the boxes evenly along the feeding lines. Don’t
empty the boxes from more than 10 cm (4 in) height.
The poults tend to stay together just after emptying the box
in dimmed light, but here you see the first poults already
running around and drinking from the pendulum drinkers.
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Flip-overs
Flip-overs are a problem for the first few days.
There are several possible reasons for poults failing to stand back up on their feet.
• Weak poults from the hatchery (overheated,
early hatched with a wide hatch window)
• Dehydrated from a long transportation
• Healthy poults with very big crops, failing to
support their balance
The longer they stay on the litter trying hard to get
back on their feet the less time you have to save
them. At high brooding temperatures dehydration
develops very fast. Poults which burn all the ‘fast’
carbohydrates on active leg movement, drain their
energy reserve and die from dehydration.
Every poult you can save, from a day old to the
slaughter age, will save you a lot of money. Some
say that flip-overs are partly caused by heat stress.
Reboxing flip-overs for 2-3 hours away from the
heat source may give a good recovery rate, provided the flip-overs are spotted quickly.
The number of flip-overs depends on several factors but
can be expected to be at least one percent of the flock.
A flip-over with a full crop digging into the litter unable to
stand back on their feet.
Don’t confuse a resting poult with a flip-over. These poults are just tired and resting in different postures.
Walk through the house and take a closer look at poults that are not moving.
Pick up the flip-overs as early as possible, dip the beak into the drinker. If the poult is not exhausted it will recover
almost immediately. If it’s been struggling for a while then time is needed to recover in a recovery pen.
116
Recovery/sanitary pen
Set up a recovery pen in every brooding ring in the
case of whole room brooding.
With single stove brooding rings, prepare an additional ring as a ‘recovery ring’. Make sure the surface of this ring has improved grip (e.g. wood wool
or reusable rubber mats, etc.) to allow weak poults
to stand up easily. If rescued early, many flip-overs
will recover, however, despite fast intervention a
few will die (splayed legs, severely dehydrated).
If leg weakness is a major issue, be suspicious of
other problems, check:
• the incubation regimes and hatch window.
• slippery floors in poult crates in the hatchers
and transport boxes.
• dead poults for signs of rickets: breaking
strength of the bones, ricket ‘rosary’ on the
ribs.
• the feed for ionophores (salinomycin, monensin
>100ppm)
An extremely high number of poults with weak legs.
If the poults arrive in cardboard boxes – use the poult
boxes with corrugated lining for a good grip.
A poult with splayed legs will never recover.
If poults arrive in reusable plastic crates – set up a recovery pen with any available material (metal wire mesh,
cardboard). Use a supplementary drinker in the pen, put
some feed in and refresh it regularly.
The wall of the rescue or quarantine pen protects weak
poults from their more active neighbors, which tend to
walk over the weak ‘competitors’ reducing their chances
for survival.
8. B ro o d i n g p e r i o d
117
Maintaining an optimal climate
LOOK-THINK-ACT
Why are poults huddled up in this corner?
Poults are overcrowding in the corners of the ring: it can be a signal of
low temperature, draft, or excessive light intensity. React accordingly!
Draft
Careful observation of the poults behavior and
turkey house conditions will determine what
adjustments should be made. In addition to visual
examination, it is very important to listen to the
poults. Excessive noise may indicate distress due
to wrong temperature, draft or lack of water or
feed.
Avoid exposure of the poults to sudden temperature or environmental changes.
Check birds every 2 hours ensuring good distribution. Brooding personnel must be prepared to
adapt to variations in poult size and activity level,
which may require modifications in brooding
temperatures, ambient house temperatures, ventilation rates, feed and water placement, and light
levels.
If the temperature is right, poults will spread out
evenly throughout the whole house/ring. They
will flock together in groups of 20 to 30 and will
regularly walk to and from, between the groups.
Most poults will be eating or drinking. If it is too
hot for the poults, they won’t flock together and
will often seek a cooler place against the walls.
They will also eat less and drink more. Poults will
also lie against the wall if the light is too bright.
Remember, in nature, poults spend their first days
hiding under their mother’s feathers. If the house
temperature is low, the poults flock together to
keep warm, so they will be slower to start eating
and drinking. The risk of losses and poor uniformity with under-developed birds increases.
How the poults are spread out says a lot about how they are feeling. Good
distribution 24 hours after placing the poults is essential to get them off to a
promising start.
Birds huddling together on one side of the
ring – raise the temperature gradually by
0.5°C (1°F) and watch them begin spreading out again. Balance your climate between
these two extremes! Check for drafts.
118
Here it seems too hot under the stove. All
poults move to the sides of the ring.
Watch the poults in the rings: if they look
alarmed and all have open beaks (panting), it’s too hot in the house. Reduce the
temperature gradually by 0.5°C (1°F), and
monitor the situation closely!
Turke y S i gnal s
Supplementary feeders
It is important to promote early feed intake in
poults in order to stimulate intestinal health and
growth. So, feed should always be readily available
and easy to access. Feed on trays that the poults
can walk on helps them to learn to eat.
The crackling noise of plastic or chick paper stimulates them to eat. This is essential in the first week
of life. After the first week you can remove the
brooding rings and supplementary feeders.
Poults tend to eat from the same source so all
feeders should have feed at all times, particularly in the first few days. By gradually taking away
supplementary feeders, the poults get used to the
new situation.
Supplementary feeders can also be seen as enrichment material that is required in some countries.
In fact, this is not necessary in brooding, and
enrichment material at this stage can even
increase the risk of impacted gizzards.
Poults are waiting for the staff to fill the fruit tray with feed.
The trays are very attractive for the poults when filled with feed. What attracts
them might be the color, the feel and/or the specific sound they make when
poults step on them.
Poults obviously prefer plastic fruit trays to paper trays,
supplementary or main feeders. The noise seems to
attract them.
8. B ro o d i n g p e r i o d
After eating a lot in the first few hours, the poults have heavy crops and get
tired. Here they are resting with their heads dangling in a feeder.
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Management – the first week
Daily poult inspection.
A healthy poult’s life is easy: eat, play, and sleep. A
turkey farmer’s life is sadly not quite so simple. A
lot of daily work has to be done to create the best
possible environment for the young poults and
grow a strong, uniform flock before transferring
birds to grow-out. After the critical first few hours,
it is important to keep focus and don’t think that
you can relax. There is a lot of work to be done!
The daily mortality pattern is a very informative
signal. Poults dying in the first 2 days indicate
a problem probably originating from before the
poults arrived on the farm e.g. poult quality or
problems in transit. High mortality around 4 to 5
days of age is the result of poults never learning to
eat or drink, commonly known as ‘starve-outs’. 4
to 5 days of age is when their internal feed stores
run out. The number of starve-outs is influenced
by management factors discussed in this chapter.
Checklist
Environment
•
•
•
•
A weak poult (non-starter) that can’t stand on its feet should be put in a recovery pen
or be culled depending on the severity and cause. This dehydrated, emaciated nonstarter has to be culled.
•
•
•
•
•
•
•
•
•
•
Assessment of the controller parameters: T,
RH%, CO2, ventilation rate, heating, water
and feed consumption per day
House inspection: house climate evaluation, air
quality in the area of the birds, litter condition
Washing and filling supplementary drinkers,
gradual removal from day 2
Washing the main drinkers – every day in the
first week
Adding fresh feed on the trays/paper/supplementary feeders, gradual removal - from day 3
Checking/adjusting feed level and system
height, feed structure
Removing manure/litter from the feeders
Moving feeders/drinkers, tilling/mixing wet
litter, adding fresh litter
Flushing the water lines (manually every 2-3
hours or automatic)
Checking/adjusting drinkers’ level, cleanliness
Checking water pH/ORT/temp.
Equipment audit (feeders, drinkers, heaters,
ventilation)
Joining two rings into one - day 5
Removal of ring walls - day 6
Turkeys
•
•
•
This very small poult on the left shows purple thin legs. They are probably
cold as well. This an indication of dehydration.
•
•
•
•
•
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Bird behavior (noises, plumage, distribution)
Consistency of feces
Assessment of poults condition (flock to
individual birds)
Collection and removal of dead birds
Flip-over collection and rehabilitation in the
recovery pens (first 2 days)
Footpad assessment
Individual birds assessment: breathing, eyes,
crop filling, belly, legs
Culling non-starters
Litter quality during the first week
Place close attention to the litter condition throughout the house. Regularly move the supplementary equipment (feeders, drinkers) to allow proper tilling and the adding of fresh litter. On the right you clearly see the growth of fungi under the additional feeders!
In case of significant water leakage the wet mass must be immediately removed from the house and replaced with fresh, dry litter. Bell
drinkers can also create problems if the water pressure/level is not
adjusted and checked regularly.
Wet litter guarantees wet footpads and a big health risk for young
poults. Corrective action is required to avoid footpad issues and leg
problems at a later age. Prevent water leakage; remove the wet litter as soon as possible.
LOOK-THINK-ACT
What do these images tell you?
After removing the brooding guards, you can clearly see the difference between the used litter and fresh litter. So just within a week,
you can already see the extent to which the litter is affected by the birds’ presence.
9. B ro o d i n g p e r i o d
121
CHAPTER 9
Rearing period (weeks 2-5)
After the first critical week in the brooding house, the brooding guards are removed and the birds
spread across the whole house. It is now essential to keep your full attention on subtle signals of
performance, health and disease.
The daily flock and facility inspection ensure the
farm runs without problems. An important prerequisite for early disease recognition is precise
observation of the flock. At least two inspections
should be made per day, allowing early recognition of anomalies. Even 1-2 days before the
disease emerges, an observant individual can recognize the deterioration of the health of the flock
through the behavior of individual birds, which
can be seen as:
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•
•
•
•
•
•
•
•
•
•
•
•
Changes in feed and water consumption
Crouching in corners and separation from the
flock
Changes in color or consistency of the feces
Changes in the smell in the turkey house
Sudden behavioral changes in the flock
Drawing in the neck
Ruffled plumage
Increased beak panting
Plaintive cheeping sounds
Sounds when breathing
Eating litter
Pale head color
Turke y S i gnal s
General flock and house inspection
Acceptable
Unacceptable
•
•
•
•
•
Birds follow walking people, are inquisitive, stretch, preen, play,
strut and have normal activities
Clean (white) feathers
Round prominent eyes
•
•
•
•
•
Birds do not move easily or are lame (sit most of the time).
Dirty, discolored feathers from wet litter, lack of preening or from
wiping eyes and nostrils on shoulder feathers.
Drooping wings
Excessive broken feathers
Slanted, dim looking eyes
Cough, ‘snick,’ sneeze, rubbing of eyes, swollen sinuses and
foamy eyes
Dead birds in the litter and cull birds in the flock
Building & Environment
•
•
•
•
•
•
Fresh clean air with good air movement
Comfortable temperature
Appropriate CO, CO2 and NH3 levels
Appropriate humidity levels
Quiet
Good lighting
•
•
Dust-free equipment
All fans, shutters and curtain opening equipment 100% operable
•
•
•
Moist but does not ‘ball’ easily
Doesn’t emit dust when disturbed
Level with minimal ridges, rings or donuts around equipment
•
•
•
•
Moist but firm fecal droppings
Viscous white cap material on fecal droppings
Few cecal droppings
Viscous dark colored cecal droppings
•
•
•
•
•
Stale air or ammonia odor
Air feels cool or hot, sticky and uncomfortable
CO and/or CO2 levels too high
Loud noise from equipment, people or outside activities
Dim or uneven lighting
Ventilation and Heating Systems
•
•
Dusty or dirty equipment and vents
Equipment in need of service
Litter
•
•
•
Uneven with many ridges and mounds
Wet soggy areas
Produces dust easily when disturbed
Droppings
•
•
•
•
Soft, mushy, fecal droppings with undigested feed
Fecal droppings with slimy, runny white caps
Excessive cecal droppings
Fluid, yellow/tan, foamy cecal droppings
General impression.
Checking the hocks and footpads.
Feeling the crop.
Looking at the feather development.
Checking the tongue and beak.
Checking the cloaca.
9. R ea r i n g p e r i o d ( w e e ks 2 -5 )
123
LOOK-THINK-ACT
Why don’t the birds eat from the pan on the left?
Feeder management
There are a wide variety of production systems
with different female/male transfer ages and body
weights. A single feeder for both young poults and
older turkeys is difficult to design, but having two
complete sets of feeding/drinking equipment in
the house is expensive. If your production cycle is
18 or 23 weeks ‘all in - all out’, installing a double
set of drinkers and feeders is unavoidable. For a
13-week cycle in the brooding period, you could
have equipment that suits the first 4 weeks, but
has replaceable parts (conus, grill, plate or collar)
that are appropriate for birds until the age of
11 weeks.
There is some litter and manure in the feeding pan. The birds refuse
to eat. On the right the same feeder two minutes after refilling with
fresh feed.
Incorrect feeding line height: the plate is
hanging low, feed windows closed. The low
feed level in the plate makes it difficult to
access for the poults.
Feeding line at correct height: the plate is
on the floor, feed windows open. The feed
level is good and easy to reach for the
poults.
X
✓
Incorrect feeder management. No feed in
the plates leads to hungry birds.
X
The correct height of the feeders is at the level of the back/shoulders of the turkey. From left to right: too low, correct and too high.
124
Turke y S i gnal s
Keep feeders clean
A good feeder allows the poults free access to
the feed from the beginning, but prevents them
from sleeping inside and contaminating the feed.
Correct management of feeding line height and
feed level in the pan prevents excessive spillage
without compromising weight gain and poult
development.
In case new equipment is required, a good
approach is to test the new samples in comparison with the existing equipment in the same
house. This helps to make the right choice for the
future and can significantly reduce the time/labor
cost and hygienic risks.
The amount of spoiled feed per day due to contamination from droppings or otherwise, can be significant. The
problem is nevertheless not so much about the feed
losses, but the risk of poults eating contaminated, molded feed. Unhealthy poults will cost you much more than
a wheelbarrow of spoiled feed.
When poults sit in the feeding pans, droppings will inevitably be left there.
Daily cleaning of the feeders is a must, otherwise you will end up with a feeding line full of manure and litter, and your poults
won’t have access to fresh feed.
9. R ea r i n g p e r i o d ( w e e ks 2 -5 )
125
Prevention of manure in feeders
Equip the control feeder with a lamp to stimulate feed consumption and protect it from poults sleeping inside. The lamp at the last feeder is
particularly important since it is the switch on/off for the entire line. It also helps to frequently run the feeding line and refresh the feed in all the
feeders.
There are various options to prevent birds from sitting in the feeders. Here a feeder with a larger cone. As the turkeys grow larger,
this cone can be removed.
Two different feeders. Poults won’t be able to climb into the one
with vertical separators.
An ingenious solution, but the poults were more ingenious!
126
Turke y S i gnal s
Prevent water spillage
A lot of litter problems are related to leaking
drinkers or water spillage by the birds. To prevent
wet litter buildup and molding under bell-drinkers
mount special hooks so you can move the drinkers
every three days to another position.
Once the waterer is moved, the litter beneath the
old location can be turned to encourage drying, or
it can be removed as needed. The drinkers in the
rearing house should be the same type and color
as the ones in the grow-out house. Sometimes
round drinkers are introduced in the house during
the final week (next to the nipples) so the birds
can get used to them. Otherwise turkeys will
become dehydrated in the grow-out house where
normally only round drinkers are used.
Donuts are formed around drinkers.
Equipment, untouched for long periods, possesses high
risks for the litter quality. Note the molding litter under this
drinker.
After removing the protective rings from days 5-7, lower
the water level until it is around 2 cm (1 in) deep. In combination with keeping drinkers at the correct height (back
of the birds) it prevents leaks and helps keep litter dry.
The system of moving the drinkers is as simple as it is effective. With two strings and hooks you easily create three positions.
9. R ea r i n g p e r i o d ( w e e ks 2 -5 )
127
Clean and cool water
Regular washing/cleaning of drinkers is an integral
part of routine turkey management. With very dirty
drinkers manual washing is unavoidable. When
beaks are trimmed, make sure feed and water
levels are kept deep enough so that the birds can
consume adequate amounts of both.
When bell drinkers are on the floor, contamination happens quickly.
Washing is recommended: 2 times per day for the first 2 days, every
day for the remainder of the first week and 2 times a week subsequently until transfer.
The temperature of this drinking water is too high
(27.7°C/82°F) due to the high brooding temperature.
There is a bigger risk of bacterial growth and the birds will
be less inclined to drink it. Frequently flush overhead lines
to provide fresh, cool water.
A simple way of cleaning drinkers is to blow the debris (litter, feed, dust and manure) out with a portable blower. It is an
easy approach, but can cause wet litter, so do it cautiously.
Simplify your work by using 2 old canisters or buckets:
1st - with clean water, 2nd – with a disinfectant. Use two
different sponges.
128
Use simple solutions: an old canister on the wall can
serve as a drainage for the waste water left after washing
the drinkers. NEVER dump the used water into the litter!
Protect equipment
Perches are not used in industrial turkey production systems, and are not necessary during the
rearing period, though they do help prevent piling
at night.
Normally, the birds begin to use roosts from 4 or
5 weeks of age. If perches/roosts are used, they
may be either the stepladder type or merely flat
frames with perches on top.
Not only do turkeys roost on the equipment, as
they grow older and stronger, their pecking may
damage it. Make sure all equipment is properly
protected.
The roosting behavior of this turkey was fatal. The animal
got stuck in the wires.
In the absence of roosts, poults will try to sit on any high objects:
wood shavings bags, straw bales, feeding and drinking lines.
Protect anything the birds should not have contact with; remember that poults are curious and have a lot of free time! It will
also facilitate better cleaning and disinfection of the equipment between the cycles.
Protect any electrical equipment, especially when poults
get older and start pecking everything around them.
9. R ea r i n g p e r i o d ( w e e ks 2 -5 )
Protect wires, preferably take them out of the poults
direct access, don’t leave them hanging freely.
129
Protect climate sensors
Sensors as well as equipment need protection
from the destructive nature of turkeys. The main
problem is that ideally sensors should take their
measurements at turkey level, which means of
course they can reach them!
At an early age the animals should get used to pecking at
distraction materials and not to equipment or each other.
Place the climate sensors at bird level so they can do their job. But remember to protect them from contact with the birds!
Climate controller sensors can provide incorrect data due
to curious poults. Do not rely solely on sensor readings.
Double check everything yourself.
130
Make sure the birds can’t get trapped in the protection...
Turke y S i gnal s
Pecking
Feather pecking and cannibalism are common
problems in turkey flocks. Below are some of their
common causes:
• Overcrowding (including inadequate feed
and water space). Sometimes caused by late
removal of poult guards.
• Boredom or idleness.
• Brooding temperatures too high or too low.
• Bright lighting tends to increase activity and
feather pecking, which can lead to cannibalism.
Less pecking occurs when poults are brooded
under daylight or artificial light of low intensity. Use bright lights only at the beginning of
the brooding period.
• Age: more common in young birds and/or birds
that reach maturity at the final stages of growout.
An early sign of pecking on the left shoulder.
The elbow is already naked.
•
•
•
•
Poor sanitation and ventilation may cause irritation of the eyes and nostrils, which then become
targets for picking by other birds.
High air speeds at bird level or underpressure
might also be a cause.
Equipment: poorly operating brooders or feeders.
Feeders/drinkers with sharp edges can cause injuries that lead to severe pecking and cannibalism
problems.
Small drops of water on a turkey from a low-pressure spraying system can attract the birds’ attention because they see it flashing in the light.
Nutrition: feather pecking and cannibalism are
often associated with diets that are deficient in
certain amino acids, protein, or sodium (salt).
Pecking each other’s head is regular pecking order behavior and might be harmless.
A young poult on the floor is an easy object
for initial aggressive pecking. Once there
are wounds it can lead to further pecking.
Nutritional factors
Make sure feed is the correct type
for the age of the bird; young birds
need higher-protein feeds. Do not
feed layer-mash or scratch feed to
turkeys. Sometimes adding fibrous
grains, such as whole oats, to the
diet helps alleviate pecking. Have
feed checked for sodium content.
The correct level of sodium is 0.15
to 0.18% of the diet. At levels
below 0.10% birds will reduce feed
intake or stop eating altogether.
Early cloaca pecking starts due to mild
diarrhea. The protruding wet cloaca
becomes attractive to the poults.
9. R ea r i n g p e r i o d ( w e e ks 2 -5 )
Once the wounds are more extensive, the
bird should be separated to recover otherwise it will be pecked to death.
131
Transfer from brooding to grow-out
Work instruction weighing
•
•
•
•
•
•
•
•
•
Catch the birds with a catching frame or pen
Use scales that are fitted with a shackle for
holding the birds firmly
Move calmly and pick up each bird correctly
Place the bird on the shackles
Wait until the bird hangs still
Record the weight from the scale
Release the bird back into the main house
area
Weight all birds in the catching pen
Repeat at 2 or 3 different locations in the
turkey house (front, middle and end)
Individual weighing of turkeys and recording is a good
monitoring tool, but quite labor intensive.
Shackles from the slaughter house are very handy to use
in the turkey house for weighing the birds as soon as the
legs are thick enough to keep the bird hanging.
132
In intensive turkey production systems, the birds
are moved from brooding/rearing to grow-out/
fattening houses. You want to minimize stress
and damage to the birds, because in early transfer
production systems (4-6 weeks) the poults are still
young and vulnerable.
Weigh birds at transfer
The transport supervisor and the driver should
know the expected stocking rate for the transport
vehicle as overcrowding can result in excessive
thermal stress, damage and suffocation in the
crates or the trailer. So it is crucial to get accurate
weights at transfer. Ideally all flocks should be
weighed a day before transfer. The sample size
should be at least 1% of the flock. Weighing is
not only practical for transport, comparing flocks
with an established benchmark is also an essential tool to evaluate management, health and
nutrition programs. Having automatic scales in
the turkey house helps in collecting more reliable
information on a daily basis. Transport scales can
also provide a reliable picture of the average flock
weight. If flock‘s uniformity is poor, manual weighing a sample can be very subjective.
Automatic scales are very accurate if calibrated in time
and allow data from a bigger number of birds to be collected on a daily basis. Locate them where large numbers of birds congregate. Note that some turkeys, like
older and heavier males, will not often step on the weighing system, so the outcome is not always reliable.
Turke y S i gnal s
Preparing for transfer
By reducing the hours of darkness in the days
just prior to catching, the birds can get used to
a higher level of activity and will be less stressed
on the actual day of catching. When the catching
crew and employees enter the house or pen, they
should walk slowly and continue to use low-level
lighting that will avoid piling and flightiness of the
flock which can result in bruises or scratches on
the birds. Some companies have also found the
use of headlamps and red lights on mobile equipment to be helpful during the catching process, to
further reduce stress for the flock. Maintenance is
a key aspect of preventing bird injury, entrapment
and death. Equipment that is used very intensively (crates, cages, loaders) should be inspected
before and after use to ensure that no holes or
sharp edges are present that can cause injury to
the birds, or permit escape. To prevent potential
pathogen transfer from flock to flock thorough
washing and disinfection is required after each
shift.
Withdrawal of feed & water
To minimize injuries, equipment is often raised to have it out of the
way as this gives the birds and the people more room to move about
freely. For birds being transferred to a fattening farm, the withdrawal
of feed can also help in reducing the chance of crop impaction or
choking when birds are handled for the moving process. Birds should
be kept hydrated as long as possible and allowed to rehydrate if there
are any serious delays in the catching process.
Culling and euthanasia during catching
The catching crew should not load or transport
any sick or injured birds. If transported, weak birds
are more likely to suffer and be less able to cope
with their environment during the transportation
process. Thus, euthanize these birds humanely on
the farm and dispose of them in accordance with
the farm’s protocols.
Examples of loading/transferring equipment
Manual catching and loading into crates.
9. R ea r i n g p e r i o d ( w e e ks 2 -5 )
Fork-lift loading crates onto the trailer when birds are transferred
between farm locations.
133
Examples of loading/transferring equipment
Manual loading and unloading of 1-tier poult lorry. The gap for filling the trailer is kept small (left) to prevent the turkeys from
escaping while loading. When unloading, the whole side can be opened (right). Double counting is usually performed at
both processes to ensure a higher higher accuracy level.
134
Inside the trailer there are partitioning fences to prevent
the birds piling up during transport.
On arrival, the turkeys have to be unloaded. This poult
mover has a floor with a conveyor belt. When unloading
the belt, the fence moves from the front of the trailer to the
back, forcing the turkeys out.
If you load turkeys from a separation area directly into a
loader you don’t have to really pick them up.
It is good to transfer turkeys in small groups to help them
remain calm.
Turke y S i gnal s
Loading and unloading
Manual or mechanical handling methods may be
used to load and unload birds from the vehicles
during the transfer procedure. For all procedures,
it is important to keep the birds calm to reduce
the risk of scratches, bruises and broken bones.
If mechanical methods are used, the belt speeds
should be carefully monitored to prevent birds
falling on each other and piling, that can lead to
suffocation if birds are overcrowded.
Manual loading average speed (crates or lorries)
Transfer age,
(weeks)
Body weight
hen (g/oz)
Body weight
tom (g/oz)
Birds/person/
hour
4
1100/39
1280/45
625
6
2355/83
2845/100
417
9
4990/176
6245/220
295
For short distances on-farm this is a simple solution.
Using cloths or plastic is an easy way to get the turkeys moving in the right
direction. Making soft noises by tapping plastic tubes against each other does
the trick as well.
During cold weather, protection (boards or tarps) is needed
on open vehicles to keep birds from getting too cold due to
low temperatures and wind speed when the vehicle is moving. During hot weather, water or cooling fans may be used
during loading or waiting periods, to limit heat stress.
Picking up the birds by the feet, carrying three or four in each hand when they
are still young is acceptable. Take the same number each time to ease the
counting process. The birds are put upright in containers or lorries. Birds can
get injured during catching, particularly if the catching team gets tired or has
to load them too quickly.
9. R ea r i n g p e r i o d ( w e e ks 2 -5 )
135
CHAPTER 10
Grow-out (week 5 to slaughter)
The grow-out period is also called the ‘fattening’ period. Different markets will tend to use different
types of turkey from Heavy-Medium to Heavy, each with its own characteristics. Heavy toms increase in
weight from 2.7 kg (5 lb) in week 6 to 22 kg (49 lb) in week 21. The heavy hens grow from 2.2 kg (4 lb)
in week 6 to 11 kg (24 lb) in week 16. Although the differences in growth rate make the management
of toms and hens very different, some basic aspects are the same. We’ll first discuss the basics and
then move on to cover specific issues for toms and hens at the end of the chapter.
Flock management
Check:
•
•
•
•
•
•
•
•
•
•
•
•
136
Behavior of the birds (sounds, feathering, spread)
Condition of the litter
Appearance of the feces (consistency, color)
Air quality (changes in smell)
Amount of dust
Environmental temperature and humidity
Consumption of feed and water
Feed level and height of the system
Feed quality
Height of the drinkers
Cleanliness of the drinking water
Turkey Signals: head coloring, mobility, uniformity
Visit the turkey house at least twice a day to inspect
the birds. It is important to recognize abnormalities
at an early stage. You will notice that your hens are
much more active than the toms. It is helpful to
have a set route when walking through the houses.
Most people start with the outside wall. This is
where the sick and the lame birds tend to gravitate
to. On reaching the end of the house, walk back
down the middle and then up the following alleyway. The return journey can be used to inspect anything that is not directly on the walk route.
Turke y S i gnal s
Monitoring growth and development
To monitor growth and development, weigh a
representative group (at least 50 birds) of each
flock when they arrive at the grow-out house. Do
this by separating a random group of birds into a
sample pen and weigh every individual bird in the
pen. This is an important tool for evaluation of
management, health and nutrition. Weigh at least
every week to:
1. assess growth
2. manage slaughter weight
3. determine effect of feed transition
4. identify issues with different feed phases
Adjust feed rapidly if necessary. Feed changes
should take place according to the phase of development (weight), but usually take place according
to age and compensatory growth can occur.
The use of automatic scales allows the farmer to
continuously monitor weight development within
the flock. Make sure the scales are calibrated frequently, at the right height, and fixed to allow for
easy stepping on by the birds.
Take into account that birds are often heavier in
winter because colder conditions will stimulate
them to consume more feed. In summer the birds
have less appetite due to the warmer temperatures.
In weeks 5–20, up to 10% mortality (cumulative)
can occur. 5% is good, 3% is very good. In the case
of bone fractures or other reasons the birds must
sometimes be killed or culled. This must be done
humanely and with special consideration of the
size of the bird.
When making your observation round, pick up animals
that need special attention.
10. G ro w - o u t ( w e e k 5 t o s l au g h ter)
Sexual development is most obvious in toms. On the top, toms at 11
weeks. On the bottom, toms at 19 weeks.
Weak and pecked animals are put in a separation/recovery pen until they are
recovered.
137
LOOK-THINK-ACT
How many sexing errors do you see here?
If you look carefully, you see a few toms in this hen flock. One in
front, one on the left side halfway. But there are at least four more…
138
Sexing errors
Sexing errors are a costly mistake: keeping toms
with hens is a loss of meat, keeping hens with
toms is a waste of feed. Often operations are
single sex, which makes it impossible to correct
sexing errors, besides creating a small separation
pen, and can create an imbalance in demand for
toms and hens in the marketplace.
The earlier the producer separates the toms from
the hens, the better performance he will have from
both sexes. It is difficult to distinguish the sexes
at an early age - apart from the tom’s courting
behavior - but as animals develop and external
signs become more prominent, you need to hurry,
as the birds are getting heavier every day and
maximum efficiency is slipping away. The optimal
age is around 10 weeks, since sexual development
becomes obvious and animals are not too heavy,
but finish the separation of toms in a hen flock at
the latest by week 11, because hens tend to peck
aggressively on the attractive snoods of the toms.
The toms in a hen flock are less developed. Hens in
a tom flock are overdeveloped and become very fat.
Hens in a tom flock. Hens are quite mobile, and if the
partitioning of the selection pen is not too high, they
might fly out, so make sure the segregation is OK.
A tom in a group of hens at 8 weeks of age. At this
moment the sex-specific characteristics start to develop.
Stay on continuous alert for sexing errors.
Separation box with toms of 85 days in a hen flock. As a
comparison a hen is placed next to the tom.
A practical window between the two partitions makes it easy
to transfer the sexing errors to the other part of the house.
Turke y S i gnal s
Bird inspection
Individual bird inspection remains an important
tool to assess the performance of the flock. In the
fattening period the breast, pecking damage and
gut health are important items to focus upon.
Pick up individual birds and check the crop. It should be
properly filled, but not pendulous.
Difference in meat deposition on the breast within a flock.
On the left a well-developed meaty breast, on the right a
pointed keel bone.
Good, dry droppings.
Signals of feather pecking. It seems OK at first glance,
but when you spread the wing you can clearly see blood
marks.
A hen turkey with good feathering (left) and dirty, rough feathers (right).
10. G ro w - o u t ( w e e k 5 t o s l au g h ter)
139
Animals for potential culling
140
As part of your daily routine, identify birds that
should be culled or cannot be taken for slaughter.
Look for weak, apathetic birds. They might not
move with the group and/or have their heads on
the litter and their feathers fluffed up. If in doubt
whether to cull or not, a basic rule applies: every
bird being unable to reach feed and water itself
needs to be culled immediately.
Unable to rise/ walk due to physical abnormality. Cull this
animal.
This bird has a swollen head and discolored skin/face.
The head is puffy and the eyes swollen shut. You might
find wounds on its head. Further examination is required.
Pecked, injured birds. Separate and treat this animal,
it could still recover.
Excessively large pendulous crops. Cull this animal.
This bird has leg issues. It can be separated from the
flock into a special sanitary section for a few days. If it
does not recover - cull it, otherwise it will be pecked to
death in the main flock.
This turkey has been run over. But if you put him back
on his feet, he will probably be okay. Close to slaughter,
toms tend to struggle to right themselves without assistance.
Turke y S i gnal s
Euthanasia
For ethical reasons, the sick and injured birds
unable to feed themselves need to be culled using
a quick and humane method. The method applied
depends on the number and weight of the birds
being culled. It must be performed by competent
personnel. Legislation regarding the methods permitted varies per country and region. In the EU,
regulation 1099/2009 is important in this respect.
Euthanasia on-farm is performed in two steps.
First you stun the animal. After that, you kill it.
With very light animals, a direct manual cervical
dislocation is allowed (< 3 kg/7 lb). For heavy,
strong birds (> 5 kg/11 lb) you will need a mechanical device to perform the cervical dislocation.
Stunning can be done with a blow on the head (<
5 kg/11 lb) or e.g. with a captive bolt pistol. The
captive bolt method is considered to be the most
humane method by welfare groups and is often
obligated. Special CO2 units are available for individual birds that could be installed in every turkey
house. Follow the instructions for all of the methods; your skills will save the animal additional distress and discomfort in their final moments.
For large numbers of birds, CO2 gas, administered
at appropriate concentrations are used. Other
inert gases, such as argon, or drugs are also used.
After initial stunning, cervical dislocation of an adult turkey can be performed
with a modified castration forceps (Burdizzo type). In this way, the neck is
crushed (cervical dislocation and transection of spine and vessels).
For animals heavier than 5 kg (11 lb)
you must use a shooting mask when
stunning. After stunning apply mechanically-assisted cervical dislocation.
A striking blow on back of the head
with a heavy, blunt instrument is very
effective and humane if done properly
(blunt trauma). The turkey should be
restrained so that the blow is properly
placed to kill the bird.
Manual cervical dislocation involves dislocation of the neck vertebrae from the cranium, separating the spinal cord and major blood vessels.
The animal should be stunned first and when done properly, the bird is killed instantly.
Grab the head firmly. Besides the shown grip, a full hand grip is possible as well. Stretch the animal and turn the head 90° to the back and in
the same movement pull it with a stretched arm gently downwards. To assure that the procedure was executed correctly, you should be able to
feel a distance as wide as a finger between head and first vertebra.
10. G ro w - o u t ( w e e k 5 t o s l au g h ter)
141
LOOK-THINK-ACT
You see this, but the animals aren’t making
any noise. What does it mean?
Temperature during grow-out
The environmental temperatures must be gradually decreased to about 15°C (60°F) after week
14. The older the birds get, the heavier they are
and the higher the metabolic activity and the heat
production of the animal itself. Keeping the birds
cool is the main issue at this stage. The behavior
of the birds is a reliable signal of the right climate.
Birds should be well spread through the turkey
house and look comfortable. Even a minor case
of heat stress can severely impair growth rate and
overall efficiency. You will likely notice heat stress
first among the toms. Their larger size means they
are less efficient at cooling themselves and there
will be less space between the birds themselves
in the turkey house. This will lead to trapped heat
and limit evaporative cooling.
This tom is panting with his mouth wide open. He is suffering from
heat stress. Other signals of heat stress are: decreased feed consumption, increased water consumption, gasping, wing spreading,
stupor, slowness and lethargy.
Preventing heat stress
These animals seem to be ‘hiding’ around the bales. The temperature might
be too low or the air speed too high. A disease outbreak might also be the
reason for such behavior.
When the weather is hot, walk through the house regularly in order to get the
animals moving. If they do not walk regularly pressure spots will form breast
blisters, due to prolonged recumbence. It also helps to get some fresh air
under the birds and prevent brooding in the litter.
142
To preventing heat stress when hot weather
arrives implement the following steps to mitigate
the risks:
1. Monitor house temperature and ventilation
closely. Heat stress can strike quickly if the
outside temperature rises or ventilation
systems are not circulating sufficient air. In dry
weather run the high-pressure fogging/cooling system on temperature and timer settings.
2. Monitor water temperature. If the water temperature becomes too high your birds will be
less inclined to drink; this will further increase
heat stress! Flush the lines and make sure the
drinking water stays cool and inviting.
3. Limit feed temporarily as the temperature
begins climbing during the day and return to
normal it in the evening. This reduces the production of metabolic heat at the hottest time
of day. During these hot days, the dark period
can be skipped to allow for compensational
feed intake during night time.
4. Provide fresh, dry litter. This will release less
moisture; lowering humidity in the air allows
the birds to cool themselves more effectively.
5. Administer vitamin C and electrolytes in the
water. This helps the birds to recover from the
stress faster than they would otherwise.
6. In case of natural ventilation you have to add
additional mechanical ventilation.
7. Adjust the finisher feed phases by increasing
the level of vitamins, minerals and metabolic
energy by 3-5%.
Turke y S i gnal s
Consequences of poor litter quality
A poor litter quality can lower levels of health and
performance in your entire flock. Footpad dermatitis, cellulitis and colibacillosis are three examples
of diseases related to litter quality. To avoid
histomonosis/blackhead a dry and clean litter is
also essential (cloacal drinking).
Footpad dermatitis
Turkeys that appear lame may have footpad dermatitis. Foodpad dermatitis is a painful condition
for the bird, that develops in the brooder house,
and makes moving around unpleasant for them.
It is caused by wet, dirty litter. In the case you
receive birds from a separate rearing farm, check
their footpads on delivery.
Black footpads are a sign of already affected skin.
Cellulitis
Cellulitis refers to a bacterial skin infection, which
commonly affects turkeys in the breast region. It
disproportionally affects toms; occurring in various
forms of severity in up to 20% of them as opposed
to only 2% of hens.
When re-using litter, cellulitis can be a big problem. Cellulitis is a disease of commercial and
breeder turkeys characterized by inflammation,
necrosis, and crepitus (a grating/crackling sound
caused by gas bubbles in the tissue). Clinical signs
can range from sudden death to reduced appetite, depression, leg weakness, recumbency, and
ataxia. The disease is characterized by reddish to
dark or greenish discoloration of the skin around
the thighs, abdomen, keel, tail region, back, and
wings. A variety of bacteria can be associated with
these lesions, but Clostridium spp are most com-
monly isolated in these cases. Very few measures
have been proven to control the disease once
it has been introduced to a farm, so the focus
should be on prevention.
Risk factors for cellulitis:
Factor
Risk
Litter quality
Higher if litter is wet or clumped together, if there is an
increased level of ammonia, or the litter is particularly
firm or less absorbent.
Keel feather
covering
Selection for increased breast muscle may result in
poor feather cover as the skin is stretched to cover a
larger area without an increase in the number of feathers
across the breast.
Fast growth
and heavy
bodyweight
Flocks with the fastest growth rates also have the highest incidence of breast blisters. The heavier the weight,
the bigger the chance of cellulitis.
Photoperiod
A constant photoperiod (23 light, 1 dark) has an
increasing effect on the presence of cellulitis. Increasing
daylength from 4 to 16 weeks showed less cellulitis, because it stimulates activity and there is less lying down.
Infectious
micro-organisms
and stress
When turkeys are stressed, bacteria can enter the
bloodstream. These bacteria can colonize in the sternal
bursa or in a pre-existing blister, causing inflammation
and infection.
Genetics
Amount of unfeathered skin (distance between feather
tracts) over the keel. The more prominent the keel bone,
the greater the risk of blisters.
Severe cellulitis due to damaged skin, with massive subcutaneous fibrin accumulation.
A mild case of footpad dermatitis (left), a severe case (middle) and an extreme case (right).
10. G ro w - o u t ( w e e k 5 t o s l au g h ter)
143
Breast lesion problems
There are two types of breast lesions.
Breast buttons: rounded evulsions in the breast
skin originating from inflammation or/and infection, forming a hard crust with a core of dead skin.
Predominantly seen in toms. It may be that foreign
matter or an infection has caused a defense mechanism to produce protective tissue around it.
Breast blisters: liquid-filled cysts under the breast
skin, evolved as a result of repeated bruising of
the keel bone or infected feather follicles. This can
happen when the toms, who have prominent keel
bones at that age, sit down for long periods on a
hard surface such as caked, dry litter. Particular
conformations in heavy birds, and poor feather coverage of the sternal bursa and skin of the keel bone,
can promote formation of breast blisters. Maintain
clean, dry, and soft litter. In addition, breast blisters
are associated with lame or weak-legged birds that
have increased skin contact with the litter.
Litter quality and E.coli
If you notice coughing, sneezing, reduced appetite,
and poor growth, together with infections of the
eyes, heart, joints, and bones, your flock could be
infected by colibacillosis. Colibacillosis is caused
by Escherichia coli, and is a huge problem for the turkey industry worldwide. Turkeys become infected
through oral uptake, inhalation or damaged footpads/skin. This should be dealt with at hatchery
and brooding level. The incidence and severity of
E. coli is highest in turkeys from 6 to 12 weeks of
age. By this age the birds have left the brooding
house and are sometimes moved onto used litter
with increased ammonia levels.
Ammonia damages the trachea, allowing E. coli
to enter and easily spread through the body. To
prevent E. coli, maintain good practices for biosecurity, water sanitation, turkey house cleanliness,
ventilation, and litter management!
A typical breast button: small round, donut-like spot on the
breast. They are not a significant economic loss as they
are often superficial and can easily be trimmed off.
Swelling and accumulation of fluid: ‘breast blister’, with a
button. Lesions with inflammatory tissue, fluid or pus must
be trimmed in the slaughterhouse if membrane ‘slips’ are
felt, or if the lesion is bigger than 1.5 cm (½ in).
A breast blister at an early stage. If you pick the animal up, you can see it better. In some countries butterfly fillets with
skin on are preferred. These fillets must be flawless. In this instance litter quality has a direct impact on sale price.
144
Turke y S i gnal s
Water in grow-out
Water consumption (liter/bird)
Sample the drinking water before the birds arrive.
Test for bacterial contamination at the source,
at the storage tanks and at the last drinker. Ideal
water consumption is about 2.5 times the feed
consumption at the start of the grow-out. In the
middle phase it doubles, and then eventually it
decreases towards the end of the grow-out period.
At the end of the grow-out, a single tom drinks
more than 1 liter of water per day. Of course, bird
weight, diet, health and environmental conditions
still affect consumption.
A shift in the feed-water relationship over several
days can be an alarm signal.
One bell type drinker must be provided per
100–150 birds. Maintain a depth at 12–20 mm
(½ to ¾ in). There are different types, so always
consult the product manual.
As a rule of thumb: the capacity of round drinkers is a live weight of about 2,000 kg (315 st) per
drinker. The capacity of nipple/cup drinkers are a
live weight of 500 kg (80 st) per drinker.
A measuring stick with the height of the drinking line. A very useful tool, but
always look at the birds as well; actual beats hypothetical every time.
Daily water consumption in grow-out
1.2
toms
1.0
0.8
hens
0.6
0.4
0.2
0
6
12
Age (weeks)
18
X
The drinkers are too low for the size of
these birds. There is a high risk of this cup
being contaminated with feces.
10. G ro w - o u t ( w e e k 5 t o s l au g h ter)
24
A lot of movement can cause spillage of water. Make sure drinkers are heavy
enough (ballast under drinker) to lower water spillage due to heavy weaving.
X
The drinkers are too high for the size of
these birds. They are not able to easily
drink the water. If they don’t drink, they
won’t eat.
✓
The drinkers are at the correct height:
always level the lip drinker with the height
of an average bird’s back.
145
Feeding in grow-out
There is a good correlation between 6-week weight and processing weights
(hens 16 wks, toms 20 wks). It is therefore important for all turkeys to have a
good start in life. Variation in weight within a flock at 6 weeks of age will also
be reflected in the variation at 20 weeks of age. It can be mitigated by changing the feed program to increase protein intake as the birds age.
Make sure quality feed is available for the birds
when they arrive. Remember that the rim of the
feed pan should be at the same height as the back
of the birds. The feeding space for a hen must be
at least 2 cm (¾ in), and for a tom 3 cm (1.2 in).
Do not change feed at the same time as the birds
move to the finisher house; this can cause them
stress and result in reduced consumption. Just
one day off feed can result in, not only a day’s loss
of growth but also an increase in susceptibility to
immune challenges and the incidence of pendulous crops. Wait a few days after moving to introduce a new feed form, and mix both feeds at first
to make adaption easier.
A shift in ingredients will also cause a shift in the
gut microflora. Limit the change in inclusion of
ingredients to a maximum of 25% from one diet to
the next.
Introduce the new feed gradually by mixing both
feeds for at least the first two days (but remember
to account for antibiotics and ionophores!).
As a management tool, it can be useful to switch
off the feeder line for a short period twice a week
to encourage the turkeys to clean the pans and to
stimulate appetite if the pellets are too weak. If
there are a lot of fines in the feeders it might be
necessary to switch the feeding line off every day.
The turkeys should never be left without any feed
for a period of longer than one hour.
Grit is important to support digestion in the gizzard (2-4 mm/¾-1½ in) quartz - stone, 1-3 times/week). For toms of 14-17 weeks of age you can use
4-6 mm (1½ to 2½ in). Shell grit can be an additional source of calcium, but
dissolves quickly in the stomach and loses its grinding effect. Stop providing
grit 3 weeks prior to slaughter so the stomach doesn’t contain stones during
the slaughtering process.
Feed intake reduction
Turkeys can temporally reject a new feed if there are noticeable
changes in color or overall appearance. For instance, high levels of
sunflower or rapeseed can result in black particles from the seed coat
visible in the pellets. Even in very small amounts, this can lead to feed
rejection. Any reduction in feed intake will directly influence growth
rates adversely.
146
Turke y S i gnal s
Behavior in grow-out
The natural behavior of turkeys is to perch on
trees and other objects. In the brooding phase
this is not a huge problem, but in grow-out, the
animals will get too heavy and can damage the
feeding lines, or other structures not designed for
a turkey’s weight. By placing a tension wire above
the drinking or feeding line you can (sometimes)
prevent this behavior.
These birds are sitting on the feed line. The birds are highly social and copy
each other’s behavior; their cumulative weight is enough to push down the preventive tension wire.
To prevent the turkeys from sitting on the feeding
line you must place a metal wire above it. Make
sure this line is tight enough to be uncomfortable
when a bird tries to perch on it. If it is broken,
repair it in time to prevent this perching behavior
from re-occurring. Putting an electrical charge
on the wire can teach the animals to stay away,
although this is not permitted in some countries.
Here the line got stuck behind a bolt. To prevent this, you could turn
the bolt to the other side. Be careful not to put the animals at risk
from sharp edges on the system.
When sitting on the feeding line, right above the feeder,
they contaminate the feeders with manure. This is a popular
position, since this is where the wire is of least bother to
them…
For animal welfare reasons, roosting areas are promoted. Make sure there is
enough airflow to prevent the occurrence of hot spots. However, using slats/
grid means that droppings fall on top of the animals underneath. Litter management is also more difficult.
10. G ro w - o u t ( w e e k 5 t o s l au g h ter)
147
At a light intensity of more than 15 lux (1.4 fc), you will certainly get a pecking
problem. Make sure the house is not too bright.
Aggressive pecking in grow-out
In cases where toms are less occupied, or are
stressed for other reasons, aggressive behaviors
can begin. Toms reach adulthood between weeks
12-14 which is when this typical tom behavior
normally begins. Pecking is not only a problem
because the toms are more aggressive, they also
spend a few weeks more together allowing injuries
to occur, both from pecking and scratching. Hens
have far fewer hierarchical behaviors. Pecking in
hens is often a general indication of a problem. It
is a sign of feeling bored or stress. Another cause
of pecking is too much air velocity, negative pressure, or air drops by the inlets. The turkeys can’t
find a comfortable place in the house to sit properly. When they get bored, the chance they begin
pecking each other increases. Ensure proper ventilation. If you’re struggling to solve the problem,
sometimes the solution could be as simple as dimming the lights. Partitions in the house may give
animals a hiding place and some shelter. Uneven
flocks and flocks with subclinical infections will
develop hierarchical pecking (only weak, sick and
small birds are pecked), not to be misinterpreted
with aggressive pecking (usually in uniform flocks,
pecked birds are the same size as pecking ones).
Sharp nails in combination with piling up or just crawling over each
other can lead to severe injuries. This may not even be caused by
fighting. The higher the stocking density and the older the birds get,
the more scratches you see in the flock. So do not postpone your
transfer from brooding to grow-out for too long.
You can recognize pecked animals by blood on the head, tail, or wing.
Protect both your tools and your turkeys from each other.
Hang them up high, out of harm’s way (if you put them in
the house at all…).
148
Turke y S i gnal s
Dealing with male aggression
Aggressive behavior is normal behavior for toms.
At 20 weeks the toms will try to push you out of the
house. They literally push you away. Do not wave
your hands, because that will be seen as a challenge,
causing them to attack you. Toms have regular ranking battles, particularly after having reached sexual
maturity. Don’t be surprised if two toms chase each
other throughout the entire house. The toms in this
case are likely equivalent in rank and their goal is
to force the other tom to submit, not to die. Still,
this behavior can be very violent, and as a producer
you should act to minimize such displays. There are
differences in the level of aggressiveness between
breeds.
The toms must walk continuously. As soon as one bird
sits down it is a sign of weakness; if it sits too long, it will
become a victim.
This animal was severely pecked. Using tetracycline or
zinc oxide spray you can try to treat it, and prevent a loss.
Place this animal in a separation pen until it recovers.
In this flock you see a number of pecked animals. Pay
particular attention to the snood and the neck.
Pecking often start at extremities, such as the snood. That’s
why some turkey producers desnood toms in the hatchery.
Aggression in toms gets more prominent by the age of
maturation and can lead to feather pecking, head pecking and cannibalism as well as a very intolerant attitude
towards the farmer!
The weakest turkeys are often victims of pecking. A weak
turkey who is a victim of pecking should be removed
to the recovery pen. Do not place this tom back in the
group because history will soon repeat itself.
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Preventing pecking - enrichment
Pecking and hysteria can lead to major problems in the flock. Turkeys pile
up and get injured. The stress causes a decrease in feed intake and growth.
Providing sodium chloride via the drinking water helps the birds to stay calm.
Add up to 1.5 kg per 1.000 liters of water (12 lb/1,000 us gal). This also has
the advantage that the drinking lines will be kept clean (micro-organisms don’t
like salt). Keeping sodium level constantly higher (0.17%) in the finisher tom
feed also helps. Magnesium oxide in the same period (1 kg/tn) has a good
sedative effect, too.
It is important to offer distraction materials to the
birds to occupy them and help prevent inappropriate pecking behavior, especially in toms. When
you set up a new flock, it is good practice to add a
few newspapers in the turkey house as distraction.
When the birds encounter a new stress it is easier
for them to release it by playing with the newspaper. Change the appearance of the material regularly to prevent the birds becoming bored. If toms
fight for a piece of distraction material, it is better
than them attacking each other!
Discourage pecking behavior:
• adequate shelter, floor and feed/water space;
• no obstacles/equipment that might cause injury;
• remove dead or sick birds immediately;
• don’t introduce new birds into an established
population;
• avoid frightening the birds;
• avoid sudden changes in type or texture of diet;
• avoid sudden changes in temperature.
The enrichment material can consist of litter material or destructible and manipulatable materials such as hay racks,
hay baskets, straw bales, alfalfa, peck stones, or used (washed) materials. But beware of Salmonella contamination! CDs, used cans, children’s toys, disposable coveralls, paper, or any ‘interesting’ items are excellent distraction
materials provided they can be suitably cleaned. Change these materials regularly, since turkeys can quickly bore of
them. Mineral blocks (top left) have a double function: it provides distraction and salt.
150
Turke y S i gnal s
Hens in grow-out: fat deposition
Hens have a tendency to deposit more fat than
toms, even if they are slaughtered at a younger
age. Fat deposition is unwanted because the
development of one kilogram of fat requires much
more energy than the development of one kilogram of muscle, and the consumer desires a lean
piece of meat.
Turkeys are like pigs and dogs: they gorge. Keep
an eye on their feed and water intake to make sure
they don’t over-eat.
In the case of over-eating (over 120% of the standard feed advice) you could limit the feed. If you
have to limit feed, do it in time. Do not limit feed
when the animal is already too fat, because by
then fatty liver issues will already exist. Monitor
flock growth by weighing regularly.
The cause of acute liver degeneration (fatty liver)
is a sudden large increase in feed intake from one
day to another. This can (for example) occur after
recovery from a period of disease or after a period
of warm weather. For instance, if an animal already
has a high intake (110% of the standard), it can
skyrocket to 120/130% given the right conditions,
or if the animal has a lower intake and the feed
intake suddenly goes up to 100%. A fatty liver can
be a sign of a metabolic issue.
To prevent fatty livers, it is important to stick to
the feeding schedule from the very beginning.
If they are left without feed for too long they will
aggressively attack the feeders once feed becomes
available. If you are going to maintain a certain
feed schedule, get them used to it from a young
age, or you will have a problem with your flock in
later weeks. Instead of limiting feed, you could
provide less energy in the feed or a different protein/energy ratio.
Fatty livers\liver degeneration
Fatty livers are very fragile, a slight mechanical impact can lead to
rupture and the birds then die as a result of internal bleeding. They
can lead to the death of a large percentage of your flock, it’s therefore
important to recognize the early signs: restless behavior of the birds is
often a first signal. In a postmortem examination, you can recognize liver degeneration from the white edges/spots. White livers can be a metabolic problem (fatty livers), but can also occur because of subclinical
HE (hemorrhagic enteritis) infection, causing immunosupression and
secondary colisepticemia. Be aware: it is always a flock-wide problem.
Healthy, dark colored liver.
A pale liver.
Early stage of liver degeneration
with white spots.
Severe liver degeneration
with clear white edges.
A hen with a lot of abdominal fat deposition (pad).
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Preparing for slaughter:
feed withdrawal
Full stomachs and crops are a dangerous source of slaughter line
contamination. Check your feed withdrawal times. Switch off the feed
lines at least 6 hours prior to loading the birds.
Feed is removed from the flock for a number of
hours before processing in order to clear the intestines of feed and feces. Birds are provided water
until they are placed on trucks for transportation
to the processing plant. Birds arriving with empty
intestines are less likely to be condemned due to
fecal contamination.
Due to significant management and environmental
differences between poultry facilities, each producer should have their own feed withdrawal program.
Basic considerations:
1. All feed should be removed from the birds 4
to 6 hours before loading, depending on the
feeding program.
2. Lights should be turned on at least 2 hours
before loading to encourage gut emptying.
If the birds sit without feed more than 12 hours, you will notice it from
the color of their gizzards – bile-green (due to reflux from the duodenum), difficult to clean and unattractive for the customers.
This is how clean gizzards should look.
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Turke y S i gnal s
Careful catching and loading
Proper handling will minimize injuries during catching & loading
An expert loading team knows how to minimize
injuries during catching and loading. Chasing the
birds too much increases the risk of skin injuries.
Handling turkeys too roughly increases the proportion of birds with broken bones. Dislocated
and broken bones are painful during catching and
transport due to handling bumps and motion.
Broken bones can also limit the birds’ ability to
move around in the crate or liner. Skin scratches,
bruising and fractures can significantly increase
the number of birds condemned.
Make sure biosecurity is in order. Both personnel
and equipment should be clean and disinfected.
If the sun is shining on the exit, the birds can rush
in that direction and they can begin jumping onto
each other. This creates scratches to the skin and
is a risky end to the careful welfare program you
had so far maintained. It can even lead to piling
up and death of heavy expensive birds just before
slaughter.
DO
Which turkeys to load?
Only healthy birds that are fit to withstand the
journey to the final destination should be loaded
and transported. Birds not loaded should be segregated according to on-farm protocol.
Do not load and transport animals that are/have:
• Weak and/or not alert
• Discharge from eyes/nostrils
• Swollen head/neck
• Skin on head or neck is dark red, purple, black
or very pale (toms can have bright blue skin in
this area)
• Bloody and/or prolapsed vents
• Emaciated and weak: very thin, easily felt
breastbone
• Dislocated, broken or exposed bones (including injury due to handling)
• Unable to rise or walk due to physical abnormality or injury. Proper handling will minimize
injuries during catching & loading
10. G ro w - o u t ( w e e k 5 t o s l au g h ter)
•
•
•
DO NOT
Minimize passing of birds between people
Place birds gently and upright in
the liner
Ensure no part of the bird is
protruding from the liner before
closing the door
•
•
•
•
Herd birds in a way likely to
cause smothering or piling
Carry the birds by the wings or
neck
Load birds with ‘do-not-load’
conditions
Swing, throw, or drop the birds
Manually catching a turkey.
Herding the turkeys towards the loading machine.
153
Maximum transport density
kg/m2 (lb/ft2)
Loading and transport
birds/m2 (birds/ft2)
Hens
Toms
4.7 (0.44)
Moderate conditions
98 (20)
9.8 (0.91)
Extreme Heat
83 (17)
8.3 (0.77)
4.4 (0.41)
10 (22)
21 (46)
Average live weight, kg (lb)
The conveyor belt loads the turkeys into the crates.
Using a loading machine is worthwhile from both
bird and labor welfare perspectives. When properly
operated the percentage of injured birds is lower
than when they are caught by hand. However, the
proportion of birds that arrive dead is slightly
higher with this method. This is partly because the
machine does not distinguish between healthy and
small or sick birds (manual catching avoids these
birds). Also make sure that the loading machine is
cleaned and disinfected properly, otherwise it can
spread diseases (e.g. Salmonella, etc.).
Crates with broken doors/floors can cause losses
due to birds falling on their backs, damaging legs
and wings, failing to stand back on their feet and
dying.
Avoid loading birds during periods of extreme
weather when possible. In cold weather make sure
the truck is away from direct wind and animals are
dry to avoid hypothermia. In hot weather decrease
loading density by 15–20%.
Protect the turkey house gate with a curtain – to avoid birds rushing to the daylight and piling up.
Make sure animals don’t get stuck in the crates.
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Turke y S i gnal s
Arrival at the slaughterhouse
Standards for slaughter quality
In modern slaughterhouses’ gas stunning is
applied before shackling.
Gas stunning has the advantage of avoiding the
distress caused by handling during unloading from
the transport crates and shackling. However, inhalation of carbon dioxide at high concentrations
has been found to cause severe respiratory distress before loss of consciousness. If done correctly CO2 stunning is humane and often enforced by
law. When turkeys are shackled live, this is painful
and distressing, especially for heavy birds. The
distress caused by shackling results in severe wing
flapping, which may cause dislocated joints and
broken bones.
Parameter
Shackling for electrical stunning.
Good
Bad
Rejects,%:
Parts, organs
<2
>5
Whole carcasses
<1
>5
Grade A
>65
<30
Grade B
<30
>50
Grade C
<2
>10
Breast blisters, %:
FPD*, %:
Grade A (0+1)
>80
<30
Grade B (2+3)
<15
>60
Grade C (4)
<1
>5
Transportation mortality, %
<0.05
>0.5
* European FPD scoring system by P.M. Hocking
Even when birds are transported correctly, you may find some dead
birds on arrival at the processing plant (DOA). Reasons for this could
include too many birds per crate or container and inadequate air
circulation around the birds (leave a gap between stacks of crates or
containers). Insufficient ventilation can mainly occur when the lorry is
stationary e.g. in a traffic jam or when parked in the waiting area at
the processing plant.
Blue light is used in the shackling room to keep the turkeys quiet, but wing flapping that might lead to bleedings,
is inevitable.
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Slaughter report information
Post-delivery of the birds you are given a report
from the processing plant. This not only provides
information about the quality of the birds, but
also gives valuable information on the preceding
grow-out cycle.
LOOK-THINK-ACT
How old is this bruise?
You can tell when a bird was injured by the color of the bruise. This
bruise would be about 48 hours old.
Color
Bruise happened
Red
2 minutes ago
Dark red and purple
12 hours ago
Light green and purple
36 hours ago
Yellowy-green and orange
48 hours ago
Yellowy-orange
72 hours ago
Light yellow
96 hours ago
Blue-black
120 hours ago
One often overlooked cause of carcass contamination can be a wrong slaughter line design. In
old turkey slaughterhouses the carcass fixation
was often by the legs only (as with broilers),
which allowed the content of removed cloaca to
run down the carcasses. New lines are designed
with a 3-spot carcass fixation (legs + neck).
Reasons for (partial) rejection at the slaughterhouse
Rejections on
arrival
Acquired during production,
quality faults
From catching
and transportation
During slaughter
and processing
Dead birds
Dermatitis
Wing fractures (fresh)
Wing fracture
Contaminated
Breast blisters (Grade A, B, C)
Femur fractures (fresh)
Skin rupture
General traumatic injury
FPD (Grade A, B, C)
Fresh hemorrhages in wings,
legs and breast
Hemorrhages in wings, legs and
breast
Abnormal color
Skin scratches (old, >5mm, >3)
Aorta rupture
Hemorrhages on the back and thigh
Cachexia
Skin ruptures (old)
Skin rupture (fresh)
Shank breaks
Ascites
Old hemorrhages in wings, legs and breast
Feathers (hair-like, follicles)
Sepsis (Colisepticemia)
Old fractures (AM) in wing and legs
Hemorrhages on thigh
Other
Dirty plumage (manure plaques)
Shank breaks
Hock joint inflammation
Feathers (hair-like, follicles)
Full crops and stomachs
Green stomachs
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Turke y S i gnal s
Hemorrhages
Subcutaneous bleeding close to the body,
probably caused by rough catching.
Wing bleeding at the extremer part, caused
by wing flapping.
Older bruise, caused around or before
catching.
Breast buttons and breast blisters
Mild breast button.
Severe breast button.
Large breast blister.
Blister after removing the skin.
The damage is obvious!
Open wing fracture without
much bleeding, so occurred
after death (during plucking).
Pop-out with bleeding (bone not
broken, but joint dislocated). The
blood is coagulated so probably
caused during catching.
Pop-out without bleeding, so
caused after death.
Wing fractures and pop-outs
Open wing fracture. This
part should be cropped and
rejected.
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157
Cachexia
Case of cachexia: extremely emaciated and malnourished
due to a chronic disorder, which causes the bird to consume its own tissues.
The same animal: it shows severe skin damage. The weakened animal was probably an easy prey for pecking and
being walked over.
Crops
Too full crop (not a pendulous crop).
158
Severe case of pendulous crop.
Turke y S i gnal s
Internal bleeding
Aorta rupture or liver damage can be registered in heavy toms under stressful conditions. Try to find the origin of the bleeding.
Broken legs or wings can be the result of
rough handling during catching/loading.
Other causes aggravated by rough handling
are: fragile bones in heavy birds due to
minerals/vitamin D3 deficiency, imbalance,
malabsorption, and lack of exercise.
Severe bleeding in the breast filet.
Skin damage
Dermatitis, this skin has to be
removed and then the meat is
probably OK.
Scratched thighs are often
caused by overcrowding, lack of
feeding/drinking space, starvation, thirst, and lethargic birds.
They can also be caused by a
poor lighting program.
Fresh wounds – check your
transportation crates for sharp
wires/edges, repair them in time
to avoid additional losses during
farm to slaughterhouse transit.
This fresh nails scratch probably
occurred during catching.
Quality control
Rejecting abnormal carcasses is essential for maintaing quality and
food safety. These charts will assist slaughterhouse personnel to use
the same objective criteria.
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159
CHAPTER 11
Gut health
Gut health is extremely important and is largely influenced by feed management. Be aware that 80% of
all immune cells are located in the gut. The healthier a digestive system, the smoother the uptake of
nutrients, and the better the birds’ growth. Proper brooding management is key to ensuring a healthy
gut and setting the poults up for later success.
You may find these balls – manure pellets covered with
dusty fraction of the litter. Sticky droppings could be a
sign of bad fat digestion. The strong droppings are not
smashed when turkeys step on it, but they ‘play with
them’. Eventually the pellet picks up the dust and fine particles of litter like a snowball, becoming dry and hard.
160
Intestinal disorders are poorly defined, some popular terms to describe impaired gut health are dysbacteriosis, bacterial enteritis (BE), small intestinal bacterial overgrowth (SIBO), clostridiosis and
wet litter. The first sign is usually a stalling in feed
intake while water consumption continues to rise
as normal. This results in an increasing water:feed
ratio. Track everything your birds are consuming
and watch out for changes. Visually you will see an
increasing number of dirty birds due to wet litter.
In later phases, you will see a stalling of water
consumption too.
Turke y S i gnal s
Signals from droppings
Probably because of its longer growing cycle, the
turkey has different gut health issues than the
chicken. Wet litter becomes a serious problem in
turkeys between eight and twelve weeks whereas
the broiler chicken has already been killed by then.
Assess normal (intestinal) droppings and cecal
droppings separately. Careful litter and manure
examination is difficult, therefore, before entering the turkey house, put the lights up to 50 lux
(4.6 fc) or use a flashlight. It is important to
observe the droppings around the drinkers, daily.
If changes are noticed, call the veterinarian for
expert advice.
Excess urine production (polyuria), observed as
‘watery white-caps’ can be caused by heat stress,
an excess of sodium, potassium, dietary crude
protein, kidney disease or starving (not eating for
a longer period). Water consumption increases
during heat stress, but birds acclimatized to high
temperatures drink less water, thus minimizing
subsequent flushing. In case of wet litter you first
have to check whether it is caused by the environment (improper ventilation, leaking drinkers) or
the animal: excessively watery droppings.
Signs of abnormal
cecal droppings:
Signs of abnormal
fecal droppings:
•
•
•
•
•
•
•
•
•
Early signs of fermentation
bubbles
Very frothy
Very voluminous and a
splatter in shape
Very watery
Wet patches on litter
Black tarry excreta
Bloody or sulfur colored
Normal cecal droppings: more viscous than intestinal droppings and
brown colored.
•
•
•
•
•
Increased size or volume
Loss of firmness/
consistency
Oily, bulky
Color change
Watery
Undigested feed
Smelly
Signals from droppings are the presence of undigested feed particles, the
moisture content and any other additional substances. Normal fecal droppings have a white cap (urates).
Cecal function
Cecal droppings are more viscous than regular
intestinal droppings and represent 1.5% of total
excreta dry matter. When there is wet litter, the
ceca are probably malfunctioning. Ceca have a delicate working mechanism and any factor upsetting
this will influence its bacterial microbiota. Under
normal circumstances, the ceca empty soon after
the lights come on in the morning and again in
the late afternoon. Upsets in function cause more
frequent emptying. In extreme problems, there
is no material present anymore, so only a watery
substance is excreted.
When the first signs of fermentation in the cecal
droppings are seen, try to note what factors may
have changed. In the past, it was common to treat
with a broad-spectrum antibiotic. This would dry
the problem for a few weeks but a repeat treatment would then be required. Antibiotic use is
now discouraged. Probiotics are said to help, but
results are not consistent.
11. G u t h e a l t h
The consistency of the droppings can easily be checked by rolling them in your
hand. The dropping should be dry. If no dirt is left behind on your hand, the
consistency is good. If the droppings stick to your hand, this indicates poor fat
digestion.
Myth or fact?
♂
♀
Based on some turkey farmers’ opinion the manure from toms differs from the manure from hens by size (smaller) and specific shape
(comma). But this is probaby a myth.
161
Abnormal droppings
Bloody manure can be an indication of a pecked/
bleeding vent or an acute outbreak of hemorrhagic enteritis (HE) (very rare).
Watery white droppings due to body protein breakdown
and excessive urate production. This could be the result
of an acute infection which results in reduced feed
consumption.
High urates content (white mass) may indicate poor
water and feed intake. Orange mucus suggests overactive mucus production and possible dysbacteriosis often
observed after transportation (starvation).
Such manure samples with green bile content from
severe feed and water intake reduction can be seen in
flocks with acute viral infections: highly pathogenic avian
influenza in this case.
In this particular case watery fecal droppings were attributed to coccidiosis. With turkey coccidiosis it is not very
typical to see blood in the droppings.
Large blood clots raises suspicion of clinical HE (although
more often sudden death is seen), but normally not with
less white urates. Can be also attributed to clostridial
necrotic enteritis. Fresh blood in droppings is a signal of
lesions close to the cloaca.
Orange matter
Orange matter in the droppings are gut scrapings; old, expelled gut cells mixed with
intestinal mucus. High feed quality and intestinal disease control are a key part of
minimizing excessive cellular sloughing. Investigate any issues contributing to birds
not eating (off feed). Orange droppings can be a sign of clinical coccidiosis or dysbacteriosis with or without associated visible damage to the intestines (is your
anticoccidial still working?), poult enteritis complex, or the birds having
gone too long without feed eating.
Check the feed, feed intake and feed supply. Also check the urates. If a bird has
not eaten at all for some time, e.g. if it is sick, the urates will often be mixed with
bile and the droppings will be green.
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Turke y S i gnal s
LOOK-THINK-ACT
What does this turkey tell you?
Dark/black droppings can indicate bleeding in the first
part of the intestinal tract (HE, NCD, AI infection or severe
clostridial NE). The blood turns almost black in color.
Another reason could be undigested fiber, fat or protein
due to inclusion of poor-quality sunflower by-products or
fat, or degraded animal proteins.
A bird in overall poor condition. This is a case of enteric Newcastle
Disease (NCD) possibly in combination with Hemorrhagic enteritis
(HE). High titers for both viruses were found in this flock.
Abnormal cecal droppings
These frothy foamy cream-caramel-yellow-brownish cecal droppings with fermentation bubbles can be attributed to clostridial dysbacteriosis or
other bacteria, avian intestinal spirochetosis (AIS, Brachyspira spp) as well as protozoan flagellates (Tetratrichomonas spp). Laboratory diagnostics are necessary to differentiate between them. Bright sulfur-yellow diarrhea can be the first sign of histomoniasis.
Stomach content
If you open up a turkey, don’t forget to have a look at the stomach content. It can provide you with important signals.
Normal stomach content.
11. G u t h e a l t h
Gizzard erosions due to mycotoxins, biogenic amines or high doses
of copper in the feed (>200 ppm).
Greenish content due to bile
reflux from slow starvation.
Petechial hemorrhages in the
proventriculus can be from
mycotoxins, as well as HE or
NCD infections.
163
Gut examination
Healthy gut
Unhealthy gut
Normal state of duodenum
Severe inflammation of duodenum
Healthy jejunum and ileum
Sloughing epithelium
Normal content of ceca
Foamy content of ceca
Good condition of cecal tonsils
Inflammation of the cecal tonsils
Normal bursa of Fabricius, an important organ in the birds’ immune
system.
164
Bursa with increased blood flow in
the tissue, due to infections.
Regular post–mortem examinations between one
and six weeks of age, even on apparently healthy
birds, give early warnings of potential health problems in the flock.
Intestinal wall development, gut fill and cecal
health are key areas for an expert to check.
And of course, the consistency of the contents.
If a flock had cecal malfunction, the ceca in a lot
of cases would be swollen and extended in length.
Some turkeys will have black tarry contents in the
ceca. On occasions only one cecum has black contents. The flow of material in and out of the ceca
has presumably stopped, leaving the contents to
turn black and finally voided resulting in the occasional black tarry droppings seen.
Signs of poor gut health are:
• thin, fragile, often translucent intestinal walls
• ballooning of the gut
• excessive blood in the intestinal vessels
• floppy gut edges after incision, lack of tonus
• abnormal content (foamy, watery,
pseudomembranes, cecal cores)
• poorly digested feed particles at the end of the
gut
• multi-colored oily aspect of the gut contents in
contact with the mucosa
Intestinal ballooning, thinning and pale appearance of the
intestinal wall, with fluid and gas can be the result of PEC
infection or clostridiosis/dysbacteriosis.
Turke y S i gnal s
Infectious causes of wet droppings
Numerous diseases cause wet droppings. This
involvement may be primary where an infectious
agent directly damages the intestinal tract or the
urinary tract, resulting in diarrhea or increased
excretion of water via the kidneys. Secondary
effects may occur where birds go off feed but
maintain water consumption, resulting in a higher
moisture content in the droppings. Changes in
water consumption may indicate disease problems. Regular measurement of water consumption
therefore is a very important aspect of turkey management.
Dysbacteriosis
Problems with wet droppings are often the result
of a change in the bacterial microbiota in the
small intestine. In healthy birds, Clostridium-like
bacteria live in the lower part of the intestine
where it is less acidic and less oxygen-rich.
Disruption of the normal environment (particularly the pH) can make Clostridium-like bacteria feel
more at home in the small intestine and disrupt
the balance in it even further by driving out other
bacteria. This can be triggered by coccidiosis, a
change in feed composition, poorly digestible feed
or simply a problem in the feed supply or house
climate.
This imbalance is called dysbacteriosis (or small
intestinal bacterial overgrowth: SIBO) which is
not a specific disease, but a secondary syndrome.
It results in poor nutrient absorption in the gut
leading to poorer feed conversion and reduced live
weight. Dysbacteriosis is often treated with antimicrobial drugs; however, you must know the primary cause for proper treatment and prevention.
Birds are clearly signaling that they have a stomach ache (complaining/noisy, rough feathering,
eating litter, standing still and ‘thick’ (hunched
posture). You can’t differentiate this behavior from
coccidiosis and necrotic enteritis and will need
to complete a post mortem investigation to make
a distinction between the two. Under Western
European production conditions (no growth promotors, no meat and bone meal) about 50% of the
flocks are treated for this condition.
11. G u t h e a l t h
LOOK-THINK-ACT
What signal do you see?
If you see birds with dirty beaks or heads, that is a signal of cecal
manure pecking. This is an indication of intestinal problems (overgrowth of clostridium or coccidiosis). Investigate this and treat the
birds if necessary.
Vicious circle of gut infection
2
1
3
4
1. Gut cells damaged by coccidiosis: proteins leak into the gut from the cells.
2. Gut villi fuse together and become shorter: smaller surface available for
bacteria to adhere to, but also for intake of nutrients, so nutrients will be
available to the ‘bad’ bacteria for longer.
3. Mucus lining on gut cells thickens: more difficult for bacteria to adhere to,
but also inhibits nutrient absorption from the lumen. More gut cells suffer
serious damage. Conditions more favorable for bad bacteria.
4. Inflammation occurs around damaged gut cells: the gut wall reddens
and softens, and gut villi can be destroyed, resulting in little or no further
absorption of nutrients. Bad bacteria flourish and cause even more
damage to the gut.
165
Coccidiosis
Coccidiosis is a protozoan disease often seen
in turkeys, caused by Eimeria species. It usually
infects immature turkeys before their immune
system develops. It causes intestinal damage and
correspondingly a decrease in healthy gut function
resulting in poorly digested feed remaining in
the intestine and the release of plasma proteins
(because of epithelial damage, inflammation),
diarrhea and possibly death. Because of the tissue damage an overgrowth of Clostridium perfringens
might occur, which can result in necrotic enteritis.
In particular Eimeria species multiplying in the
small and mid-intestines, might evoke necrotic
enteritis, resulting in high mortality if not treated
adequately. In case of subclinical coccidiosis, lesions will be less pronounced but feed conversion
is poor and the birds grow less. The condition of
the droppings (more liquid) and behavior (hurdled
position) of the birds is key to observe coccidiosis.
Six species of Eimeria have been identified that
cause damage in turkeys: E. meleagrimitis,
E. dispersa, E. innocua, E. meleagridis, E. gallopavonis,
and E. adenoeides. Coccidia of chickens and other
birds and animals does not infect turkeys and vice
versa.
Coccidial oocysts are shed in the feces of infected
birds and must be sporulated to become infective.
Sporulated oocysts are environmentally stable and
are not killed by most disinfectants. Ammonia will
kill oocysts and this can be used to disinfect the
empty turkey house.
Prevention of coccidiosis
The key to good coccidiosis control is prevention
by means of anticoccidials in the feed or a vaccination, and good biosecurity in between growouts (internal and external). Prevent the build-up
of oocytes in the environment by removing damp
litter and avoiding wet spots.
Prevent transmission via fecal material from infected birds. Feces from infected birds can enter the
turkey house on crates, equipment, footwear, clothes, pets, wild animals, etc.
Bear in mind that every anticoccidial loses effectiveness over time as the coccidia develop resistance to it. Signs that can indicate reduced effectiveness are an increase in feed conversion ratio, a
drop in daily gain, digestive problems, droppings
quality, wet litter, and clinical symptoms of coccidiosis. After rotation to another anticoccidial
the resistant strains will be killed eventually and
you can start using the first anticoccidial again.
In turkeys often a winter and summer rotational
program is used. The choice of coccidiostats in
turkeys is very limited, compared to chickens.
1
2
Life cycle of Eimeria
5
♂
♀
3
4
7
166
6
1. The turkey takes up sporulated oocysts from the litter.
2. The oocysts are crushed in the gizzard and/or intestines
so that sporozoites are released. When reaching the
intestines, the sporozoites penetrate the intestinal cells,
where they grow into large schizonts.
3. The schizonts break open, and a great number of merozoites are released ready to infect new cells.
4. This asexual reproduction can occur several times in the
intestines, depending on the Eimeria species.
5. Reproductive cells (gametes) are formed from the last
generation, which then develop and reproduce sexually.
6. A fertile embryo (zygote) forms a cyst wall around itself.
The oocysts are excreted with the droppings.
7. The non-infectious oocysts develop into infectious
sporulated oocysts in the litter.
Turke y S i gnal s
Characteristics of Eimeria species
A coccidiosis case: the poult is not preening but has a
hunched posture and cold feet. Note the upright tufty
feathers (a sign of gut problems).
The various types of coccidiosis are very difficult
to identify. Some of them are active in a specific
part of the intestines, but only a very well-trained
individual will be able to see the difference in a
post-mortem dissection. Monitoring and diagnosis of turkey coccidiosis is complicated as mixed
infections can be present and lesions are not specific enough per species. Generally, an infection
with Eimeria spp. causes loss of appetite, increased
vocalization (noisy), diarrhea, poor weight gain and
possible weight loss, and dehydration leading to
morbidity and possible mortality.
Eimeria adenoeides and Eimeria meleagridis
Eimeria adenoeides and E. meleagridis cause lesions in the ceca. Gross lesions consist of watery, creamy-colored, caseous material
in the ceca which might form whitish cecal cores. It is important to mention that these cecal cores should be differentiated from cores
formed due to Histomonosis (blackhead) or salmonellosis. These can be differentiated by laboratory analysis. The time between the
ingestion of oocysts and the detection of coccidia in the intestine or manure is 4–5 days.
Multiplication of E. adenoeides (indicated in yellow) is occurring in the
lower part of the gut with
the formation of lesions
in the ceca (indicated
in red).
Coccidiosis lesions caused by cecal
Eimeria species.
Multiplication of E.
meleagridis is taking
place in the mid intestine
and in the ceca. Lesions
are formed in the ceca
(indicated in red).
Eimeria gallopavonis
Eimeria meleagrimitis
Eimeria gallopavonis lesions are rarely seen in the field.
They are characterized by the presence of caseous material
which is mainly found in the cecal neck while the content
of the cecal pouch has a normal appearance. The time
between the ingestion of coccidial oocysts and the detection of coccidia in the intestine or manure is 6 days.
Eimeria meleagrimitis seems to be one of the most important
and prevalent species in the field. It has a preference for the
mid intestine. Gross lesions appear throughout the small
intestine and consist of the formation of mucus, pseudo
membranes, and watery content. The time between the
ingestion of coccidial oocysts and the detection of coccidia
in the intestine or manure is around 4–5 days.
Lesions caused by a mixed infection
of cecal coccidiosis.
Lesions in the mid intestine due to E.
meleagrimitis.
11. G u t h e a l t h
Eimeria gallopavonis multiplies in the
ileum, cecal neck,
and rectum.
Main locations where
E. meleagrimitis is
found are in the small
intestine.
167
Anticoccidial programs
The anticoccidial products can be divided into two
categories: ionophores and chemical products.
The majority of turkey producers include one anticoccidial product in the feed during the production cycle (full program). This starts from the first
day until the age of 10–12 weeks. Due to increased
out-breaks of coccidiosis or NE, shuttle programs
(two different anticoccidials during production
cycle) are becoming more popular.
Indeed, these shuttle programs are advisable in
the case of elevated coccidiosis pressure in farms.
Most commonly, chemical products or chemical/
ionophore combination products will be used for
the first 5–6 weeks of age. This is then followed
by ionophore anticoccidials in the grower stages,
most commonly at the lowest registered doses to
avoid the risk of toxicity by sudden introduction of
these products in older turkeys.
By inclusion of chemical anticoccidial products in
a full program a decrease of the oocyst load in the
houses can be achieved (‘clean up’ program), this
program is advisable when decreased sensitivity
to the frequently used products has been identified. The decision about changing the coccidiostat
should be made based on microscopic evaluation
of the feces.
Substitutions to AGPs
Antimicrobial growth promoters (AGPs) reduce
the risk of gut problems and promote better feed
conversion and a higher final weight. The use of
some of these agents increases the risk of resistance development in bacteria and is therefore
banned in many countries. Numerous alternatives
are available on the market, promising to become
a sound substitute to AGPs.
Monovalent
- monensin
Divalent
- lasalocid
Ionophores
Monovalent glycoside
- maduramicin
Chemical agents
- halofuginone
- diclazuril
- robenidine
- amprolium
- clopidol
- zoalene
Vaccines
It is important to work with a rotation system to minimize the risk of coccidial
resistance. Coccidiostats are divided into two groups: chemical and ionophore.
Ionophores can be further subdivided into different families: monovalent, divalent
and monovalent glycoside. The principle of a rotation regime is simple: change
product regularly.
168
You can start medicating via the drinking water as soon
as you notice gut problems. It is better to medicate via
the drinking water than via the feed, as a sick turkey will
stop eating before they stop drinking. After the medication has run its course, flush pipes thoroughly and clean
them with hydrogen peroxide.
Turke y S i gnal s
Coccidiosis vaccination
Only a limited number of different live coccidiosis vaccines are availabel for turkeys. As these
vaccines contain non-attenuated, so called `wild
type’ strains of Eimeria, their availability has
been restricted to only a few markets, like USA. In
Europe, no coccidiosis vaccines have been available so far. It is assumed that coccidiosis vaccines
restore the sensitivity of the Eimeria species to
anticoccidials.
The increasing demand for antibiotic-free poultry
feed in some markets will require the development
of innovative and improved turkey vaccines to also
become available in Europe.
During application (spray, drinking water, eye
drop), coccidiosis vaccines must be stirred continuously to ensure that the oocysts stay in suspension. If oocysts are allowed to settle at the bottom, significant variation will occur in the actual
oocyst dose delivered. After vaccination, the poult
boxes should be placed in an area with abundant
light in order to continue stimulating vaccine consumption by preening.
One of the keys to a successful coccidiosis vaccination program is the recycling process after the
first cycle of the Eimeria parasites. Five to seven
days after vaccination, poults will begin excreting
vaccine strain oocysts in their feces, re-exposing
the flock, further stimulating the poults’ immune
response, and increasing their level of immunity.
To achieve a suitable environment for sporulation and uniform contact, it’s critical to manage
the stocking density of the flock. Measuring litter
moisture is an easy way to determine whether the
environment is suitable for sporulation. It can also
be easily adjusted by adapting the stocking density to either increase litter moisture or reduce it. If
the startup is in rings: litter transplantation can be
necessary. The birds must stay on infected litter to
prevent breaking the cycle.
Red colored vaccination fluid used in spray coccidiosis vaccination.
For optimal immunity:
•
•
•
•
•
•
Avoid anticoccidials
Avoid antibiotics (Sulpha’s/Tetracyclines, etc.)
Ensure adequate feeder and drinker space
Limit possible stressors (ventilation, temperature, handling, etc.)
Control mycotoxins in the feed
Prevent immuno-suppressive diseases (HE)
A coccidiosis vaccination is administered through a weakened strain, but they follow a normal life cycle. With each cycle
the poults immune system is challenged again and increases in strength.
11. G u t h e a l t h
169
Histomonosis (blackhead)
Typical histomonosis damage to the liver.
Hard lumps of caseous material in the cecum after
autopsy. This is caused by H. meleagridis.
Life cycle of Histomonas meleagridis
Blackhead (histomonosis, histomoniasis) is
caused by the protozoan Histomonas meleagridis and
characterized by increased drinking and decreased
eating. After a few days watery
sulfur colored droppings, drowsiness, weakness,
dry-ruffled feathers, dark cyanotic head, and lesions in the liver and ceca will occur. Mortality is
high, especially in young poults (< 12 weeks).
Histomonads are very stable inside cecal worm
eggs (Heterakis gallinarum) that are ingested by
earthworms (can be carried over from flock to
flock). Birds can be infected by ingesting infected
cecal worm eggs, by eating infected earthworms
or directly by cloacal drinking. Cloacal drinking
is the back flow of urine from the cloaca to the
ceca (re-use of nitrogen). Histomonads in the
litter can attach themselves to the cloaca when
the bird is sitting, which is then washed up to
the ceca. Migration fences can avoid spreading
of the disease throughout a whole turkey house.
Separate turkey flocks from chickens and separate
young birds from older birds. Use good sanitation
practices in the brooding area. Rotate range areas
frequently. Currently there is no registered preventive medication against histomonosis and it therefore poses a big threat to the turkey industry.
Carrier bird:
Cecal worm larvae develop
into mature worms.
H. meleagridis infects the
ovary of these worms.
Cecal worms (Heterakis gallinarum)
produce eggs containing
H. meleagridis.
Parasite cycle in carrier bird
Cecal worm eggs develop into
larvae in the soil/litter where
they are deposited.
Earthworms ingest cecal worm
larvae containing histomonads
and serve as a host.
Infection by the histomonads often results in
death.
Indirect infection:
Earthworms are ingested by
the turkey.
170
Direct infection:
Cecal worm larvae are ingested by
the turkey or Histomonas parasites
enter by cloacal drinking.
Hemorrhagic enteritis (HE)
Hemorrhagic enteritis is an inflammation of the intestinal tract with edema, congestion, ballooning and
hemorrhage of the intestinal lining as a result.
Intestinal contents may by bright red to dark purple. An enlarged, mottled spleen is often observed
together with the intestinal lesions (marbled
spleen).
This is sometimes called ‘bloody gut.’ It is caused
by an intestinal adenovirus. HE is a severe bloody
diarrhea occurring in poults between 6-12 weeks of
age or younger. This condition can cause excessive
mortality in unvaccinated flocks.
Bright red to dark purple diarrhea can be observed
in the litter. HE is associated with poor livability
and can also cause immunosuppression resulting
in chronic or subclinical infections later in the
grow-out. E. coli is the most common secondary
infection associated with HE.
Prevention and treatment
Vaccination with a live vaccine is the best prevention,
that is administered via the drinking water between
3.5 to 5.5 weeks of age. The best results are obtained
when repeated at different ages. On multi-age farms,
HE can occur in unvaccinated poults from horizontal
spread from older birds on the same farm. Strict
biosecurity is an important part of a good prevention
program, coupled with timely vaccination. There is
no treatment for HE. In some cases antibiotics may
be needed to treat the secondary infections resulting
from immunosuppression.
Signs of septicemia (E. coli circulation in blood) can be
seen on the surface of the enlarged liver: white lesions
of various size and shape. These livers turn green when
exposed to the air at autopsy.
Hemorrhagic enteritis is also called ‘bloody gut’. This is
clearly seen when you open up a turkey and take out the
intestines. It is filled with blood.
The content of the intestines is of a bloody purple color.
An enlarged, marbled spleen is specific for acute
Hemorrhagic enteritis. On the left a normal spleen.
Ceca full of clotted blood.
11. G u t h e a l t h
171
Necrotic enteritis (NE)
Clostridium perfringens, a normal inhabitant of the
ceca, is the cause of necrotic enteritis (NE) and is
evoked by predisposing factors. Necrotic enteritis is
characterized by severe ulceration of the intestinal
mucosa and high mortality, in the acute form up to
50%. Toxines produced by the Clostridium bacteria
are known to damage mucus and the bacteria use
mucus as a feed source. Mucus in the intestines
is essential as a physical protective barrier against
other bacteria and immune recognition. Clinical
signs include depression, dehydration, drowsiness, ruffled feathers, diarrhea, increased water
consumption and decreased feed consumption.
In the subclinical form, damage to the intestinal
mucosa also leads to decreased digestion and
absorption but without associated mortality.
However, performance is severely reduced, even if
mortality remains low.
Necrotic enteritis is a major challenge for the turkey industry. On the one hand the turkeys receive
a lot of protein in their feed ration, but on the
other hand antimicrobial growth promotors are
not permitted in many countries. Both of these
factors are in favor of Clostridium overgrowth.
Bird appearance
The overall appearance of affected birds is not very
specific, but a few details make the difference.
Affected birds have a pale head, ruff collar feathers
(as worn in William Shakespeare’s time) and
almond-shaped eyes. When you come closer and
try to catch them, these birds will only escape a
few meters away before sitting down again immediately. When pushed gently, they walk like a stork:
slowly with pronounced steps. When handling the
bird, almost all birds will have cold feet.
This is usually not the case in ‘ordinary enteritis’.
Prevention and treatment
The overgrowth of Clostridium spp. often occurs
after initial intestinal damage caused by coccidia
or ascarids (roundworms). Programs to reduce
coccidia and ascarid loads in the intestine can
reduce the occurrence of necrotic enteritis.
Necrotic enteritis could also be caused by feed
rations containing fish meal and wheat middlings,
which can create an intestinal environment that is
favorable for Clostridium spp. The use of these feed
ingredients should be limited. Limit the amount
of protein in the feed ration, make gradual feed
changes, use ingredients that stimulate gut health
(safe raw materials, etheric oils, etc.)
Protein
Clostridium-like bacteria love protein. Often this is protein that remains in the gut for longer as a result of damage
to the gut cells caused by coccidiosis. In addition, damage to the gut causes proteins to leak into the gut lumen
from the gut wall. You can add lower-protein raw materials such as wheat grains to the feed. This will reduce the
protein content of the feed, and the feed will remain in the stomach for longer (longer contact time with enzymes
means better digestion).
Through the intestinal wall of duodenum you can see the white
unhealthy tissue.
172
In this case of necrotic enteritis you can see died-off tissue
(necrotic) along the small intestine.
Turke y S i gnal s
Other gut infections
Infections by (flagellated) protozoa
In turkeys, several types of protozoa (besides
histomonas and eimeria) are also associated
with enteric disease. Protozoal enteritis can be
present with general signs, including dehydration,
loss of appetite (off-feed), loose droppings and
watery intestinal contents. Diagnosis is confirmed by veterinary microscopic evaluation of fresh
intestinal contact from live birds. Examples are:
Cochlosoma, Spironucleus and Tetratrichomonas.
Colibacillosis
Primary enteritis in poultry caused by avian pathogenic E. coli (APEC) is rare. Infected birds may have
diarrhea and be dehydrated. Intestines are pale
and distended with fluid, especially ceca, which are
fluid filled and may contain gas. See also page 185.
Salmonella
(Subclinical) salmonella infections are common in
all species of domestic poultry. In an outbreak
with clinical signs, affected birds are depressed,
reluctant to move and have ruffled feathers and
drooping wings. Diarrhea with pasting of the
feathers around the vent is commonly seen. White,
viscous droppings can be seen in cases of pullorum disease, caused by S. pullorum.
Astrovirus
Astrovirus infections occur mostly in the first four
weeks of the life of a turkey. Avian nephritis virus
(ANV) causes an acute, highly contagious, typically
subclinical disease of young poults that produces
lesions in the kidneys.
Rotavirus infection
Rotavirus infection is frequently associated with
outbreaks of diarrhea. Probably the destruction
of epithelial intestinal cells results in malabsorption and increased water secretion by the
bird. Symptoms in young birds are diarrhea with
associated dehydration, poor feed conversion and
weight gains. Most infections in turkeys involve
birds younger than six weeks.
Crop mycosis (candidiasis)
Candidiasis is a fungal disease of the digestive
tract. Lesions are found in the crop and consist of
thickened mucosa and whitish, raised spots. The
same lesions may be seen in the mouth and esophagus. Listlessness and lack of eating are signals.
Young chicks and poults are most susceptible. It
commonly develops after use of therapeutic levels
of various antibiotics or when using unsanitary
drinking facilities.
Poult enteritis complex
Poult enteritis complex (PEC) or enteritis mortality syndrome (PEMS) is a general term for
infectious intestinal diseases of young turkeys.
All forms of PEC are multifactorial, transmissible
and infectious. It is characterized by alteration of
the intestinal mucosa, generally by one or more
viruses, inflammation and proliferation of secondary agents, usually bacteria. PEC occurs wherever turkeys are raised commercially and causes
enormous economic loss, mostly from the failure
of the turkey to reach its genetic potential.
The crop. On the right you see the white raised spots,
caused by crop mycosis.
11. G u t h e a l t h
173
CHAPTER 12
Health and disease
Heritage turkeys are hardy and robust birds that are easily managed. The commercial production
strains are faster growing and do not always display this toughness. They are more susceptible to a
variety of diseases. In this chapter we mention just some of the main turkey diseases.
Further health issues such as intestinal problems are covered in a separate chapter of the book.
Some individual birds remain healthy even though
they are carriers of disease. When stressed, these
carriers become a source of infection. Stress is
an underlying factor in a bird’s ability to naturally
combat pathogens, and should therefore be kept
to a minimum. Provide a comfortable and relaxed
farm environment at all times. Stocking density is
considered one of the most harmful stress factors
in turkeys. So think twice before increasing the
number of your poults. A consistent schedule and
handling procedures will minimize stress. Stress
obviously serves as a starting point for any malfunction in the multiple physiological systems and
organs of the bird. Strong or chronic stresses lead
to loss of natural resistance, flock performance,
final product quality and even death.
174
Observe all birds several times a day to become
familiar with their normal behavior. Birds may not
show obvious signs of illness until a disease is in
an advanced state.
If the farmer is careful enough to observe the first
signals of a problem, behavioral changes or subtle
clinical signs, the situation can likely be reversed
via management improvements, and the flock
brought back on track.
A disease in the flock is usually accompanied by
several warning signs:
1. sudden change (drop or increase) in feed or
water consumption
2. change in the birds’ behavior and appearance
3. appearance of sick or dead birds
Turke y S i gnal s
Healthy turkey
clear eyes
red and clear wattles
nice and cheerful sound
clean nostrils
behavior: alert, comes towards you
pink and moist
mucous membranes
straight neck
straight back
closed beak
no injuries to head,
neck, back, and tail
firm crop
proudly upright posture
full tail
wings well positioned along the body
clean, moist, and nicely pink cloaca
clean, smooth, and even plumage
smooth and flexible joints
straight, yellow legs, not overly warm or cold
straight toes
short nails
firm, dry droppings
smooth footpads
Unhealthy turkey
eyes: mucous, semi-closed, frothy,
swollen, white, dry, dull/pale in color
screaming, squeaking,
congested sound
behavior: sits/stands still in a
corner, lethargic, and slow
bald elbows
wattles and snood: pale, rough,
and shriveled
curved neck or
extremely stretched out
dirty feathers
black/necrotic snood due
to pecking
drooping and hunched
up posture
convex back
wings drooping along the
body or standing upward
dirty, moist nostrils
scratched hips
gasping
scabs on
the neck
pecked tail feathers
tongue and mucous
pendulous crop
membranes pale
pale or dark-red
and dry
head, often hidden
breast blisters
under the wing
dirty, bulging, dry, and pale cloaca
thick joints
lame, deformed legs
(O/X-shaped)
abnormal droppings: discolored
(bloody, black, sulfur), foamy and/or liquid
legs too hot or too cold
short legs
12. H e a l t h a n d d i s e a s e
long nails,
crooked/curled
toes
footpad
lesions
175
Diagnosis
When it is apparent that a disease is present, seek
the advice of a poultry vet. Signs that appear today
are usually the result of problems that may have
begun 2 or 3 weeks ago. Do not just use drugs or
antibiotics indiscriminately; this may be of little
value and only result in a waste of money. Early
diagnosis and fast treatment are always recommended as the quickest ways to solve poultry disease problems.
Behavior of an unhealthy flock. Turkeys are very active animals and should not
all be lying down. Something is wrong here.
Testing
If you want to be sure about a disease, apply proper tests. It is difficult to get good, useful testing
unless you know what you need to test for. Labs
perform lab work, not veterinarian work. So an
examination in the turkey house by a vet is the
first step. Your veterinarian can send a sample to
the lab and direct them in what to look for. The
sample should include two or more sick, or recently dead birds. Preserve dead specimens by keeping
them cool to prevent decomposition.
Appearance. The head of this young hen is a bit too red. This is a sign of
dehydration.
Manure sampling or blood sampling can be done on a
regular basis as part of a health plan.
Very low uniformity. You see several small turkeys. They should have been
selected out some time ago. It is important to try and find the cause of this.
Notice the wet manure spots and also far too many cecal droppings on the
litter. There are also digestive problems in this flock.
176
Hen, definitely not feeling well.
Turke y S i gnal s
Classification of diseases
Infectious diseases can be caused by several agents: viruses, bacteria, fungi and parasites. Non-infectious
disorders are often caused by nutritional factors, such as vitamin and mineral deficiencies. Health issues are
often classified based on these causes. However, it can be more practical to classify disorders by organ system:
• Gut health (see chapter 11)
• Leg weakness (musculoskeletal)
• Respiratory distress
• Sudden death/cardiovascular diseases/highly pathogenic diseases
Leg problems
Locomotion problems are a significant economic
issue. The most commonly observed conditions are:
• Spraddle/splayed legs
• Swollen footpads - Footpad Dermatitis (FPD,
bumblefoot)
• Arthritis (articular inflammation)
• Thickening above the hock (tenosynovitis)
• Varus (O)/valgus (X)-deformations (VVD),
Perosis (slipped tendon), Shaky Leg Syndrome
(SLS)
• Soft bones in young poults (rickets) or fragile
bones in old birds (osteoporosis)
• Inability to walk/stand without visible abnormalities (TD/tibial dischondroplasia or FHN/
femoral head necrosis)
• Spiral fractures of the tibia or femur in heavy
toms
They can’t all be covered in this book so just a few
abnormalities have been selected.
Abnormal posture indicative of leg weakness.
11. H e a l t h a n d d i s e a s e
Examples of
musculoskeletal problems
•
•
•
•
•
Tibial Dyschondroplasia (TD)
Infectious Synovitis (MS)
Rickets
Chondrodystrophy
Footpad dermatitis
Tibia or femur often break in a spiral way, damaging tissues from the sharp edges of the broken bone, causing
a lot of pain for the turkey.
177
Hips and knees
Femoral head necrosis or Bacterial
Chondronecrosis with Osteomyelitis
FHN/BCO is an inflammation of the joint (arthritis) and/or
bone marrow (osteomyelitis) of the femoral head caused
by a bacterial infection leading to the detachment or even
complete destruction (necrosis) of the femoral head.
Possible causes are bacterial inflammation, bone marrow
infection (osteomyelitis) due to stress (leaky gut), hatching
egg contamination, inadequate bone calcification or too
rapid growth. This can be seen from day-olds to the
transfer age. If the problem is seen regularly, the cause(s)
should be investigated systematically.
A healthy cartilage of the femoral
head stays in its’ place when the
bone is turned out of the joint.
A broken femur due to BCO. The
affected bone is so weak that it
breaks under any force applied, leaving the femoral head in the socket of
the hip.
Tibial dyschondroplasia (TD)
Dyschondroplasia causes 5-25% of the lameness in turkeys. Tibial dyschondroplasia is a developmental defect
during bone growth in which growth plate cartilage fails
to fully convert to bone (ossify). This results in retained
cartilage (‘cartilage plug’) at the end of the bone, usually
in the leg and often near the stifle joint. The lesion occurs
most often in the leg bones, although other bones can
be involved. The cause is multifactorial: rapid growth,
nutrition, and genetics play a role. Calcium:phosphorous
ratio, vitamin D3 and chloride ion imbalance are considered important risk factors for TD. The most effective
control measures generally involve adjustment of Ca:P
and vitamin D3.
Normal. Growth plate is normal in
thickness all the way across the cut,
and it is uniform in thickness from
one end of the cut to the other.
Rickets with a widened growth plate
due to Ca/Vit D imbalance.
178
Severe TD. Little or no normal growth
plate left. Cartilage plug extends
down the shaft of the bone.
Phosphorus deficiency rickets. The
growth plate has no distinct basal
border.
Rickets
Bones are bent and too soft. Afflicted poults appear to
have ‘rubber’ skeletons. The symptoms are easy to see
at 2-4 weeks of age, but the first indications can be seen
earlier than that with the poults being reluctant to walk
very far and some poults using their wings to aid walking.
The cause is nutritional. Therefore, a sample of feed
(500 g) should be retained from every load of feed in
plastic bags, clearly identified with a date, ration name
etc. If a feed problem is suspected, the feed mill should
be informed quickly and the samples sent for analysis
(calcium, phosphorus). There are various causes, such
as:
• Insufficiently calcification (inadequate calcium and/or
phosphorous)
• Vitamin D deficiency
• Excessive levels of either calcium or phosphorous
(dev. of insoluble mineral complexes)
• High growth rates (more Ca/P/Vit D required to maintain bone development)
• Excessive magnesium levels
• Mycotoxins
Turke y S i gnal s
Hocks
Perosis
Perosis in turkeys (slipped tendon) is a leg problem
caused by a deficiency of choline in the diet, along with
some other dietary factors. Hereditary factors can also
play a part. Bone strength appears normal, but the large
tendon at the rear of the hock slips to one side, resulting
in a twisted leg. If permanently crippled, the bird should
be euthananized. Most turkeys with perosis respond to
early use of additional choline in the feed.
Perosis (slipped tendon).
The Achilles tendon slips off the
poorly formed joint.
Severe arthritis/synovitis in a turkey
poult.
A swab of the exudate in the swollen
hock joint is necessary to conduct a
bacteriological examination.
Diarrhea, sticky manure and wet
litter are starting points for footpad
dermatitis.
Severe case of footpad dermatitis.
Infectious arthritis/synovitis
You see swollen hocks that feel warm. Depending on
the causative agent, the joint may contain clear fluid to
colored pus. Treatment should only be done after determination of the causative agent.
Footpad and toes
Footpad dermatitis (FPD)
Footpad dermatitis is a painful condition for the bird. It
is caused by wet, dirty litter. Nutritional factors play an
indirect role, so find the reason for the diarrhea and work
hard on the litter.
See also on page 143.
12. H e a l t h a n d d i s e a s e
179
Crooked, curled toes
Crooked toe is a developmental anomaly in developing,
young turkeys, affecting a few birds in most flocks. The
phalanges are twisted sideways. Infrared brooding and
wire floors appear to increase the incidence. Use of
roosts helps decrease the incidence level.
Curled toe is a different condition that occurs due to
riboflavin deficiency in young birds, in which the toes are
curled inwards and the primary lesion is in the peripheral
nerves. Crooked, curled toes may originate from a mild
form of rickets.
Curled toes.
Crooked toes.
Leg deformity
Normal legs.
Rotated tibia.
O-legs (varus).
X-legs (valgus).
With severe deformities, birds have difficulty walking and
standing, and therefore reduced access to feed and water. They also bruise more easily and are often victims of
aggression, especially in older tom flocks where mortality
associated with trauma to lame birds can reach 1% to
2% per week. Varus (o-legs, cowboy) and valgus (x-legs)
deformities are the most common long-bone distortions
found in turkeys.
Splay leg occurs in young (less than 2 weeks) poults
and is usually associated with an inexperienced hatchery
crew mishandling the legs of hatchlings. Splay leg also
occurs when poults are placed on slippery bedding, such
as smooth paper.
Tibial rotation (twisted leg) is a 90-degree rotation of the
lower leg bone and must by differentiated from slipped
tendon (perosis), because the tendon remains in place
with tibial rotation. Angular limb deformities can also be
a result of inadequate protein, calcium, phosphorous or
vitamin D3 in the ration.
Chondrodystrophy is a nutritional as well as a developmental (genetic) disease of abnormal cartilage formation,
resulting in shortened long bones and enlarged joints.
Day-old poults. The poult in the middle is normal, the others show symptoms
of chondrodystrophy (short bones, enlarged joints).
180
Turke y S i gnal s
Respiratory problems
Examples of
respiratory problems
A turkey’s lungs are small and do not expand.
Unlike mammals, the lungs of birds end in air
sacs, distributed throughout the body, which are
very vulnerable tissues. It is vital to note the first
respiratory signal through careful observation of
the flock and individual turkeys. Subtle breathing
sounds in the initial stage of the disease will not
be immediately obvious in a noisy turkey house
environment.
Anatomy
•
•
•
•
•
Ornithobacterium rhinotracheale (ORT)
Turkey rhinotracheitis (TRT)
Aspergillosis
Turkey Coryza (Bordetellosis)
Mycoplasmosis (MG)
nostrils
nasal cavity:
consists of
several interconnected chambers.
beak opening
windpipe (trachea):
reinforced with cartilage rings to prevent
it from closing during
breathing. Branches
into two smaller tubes
(bronchi).
Pick up suspicious birds in different areas of the house
and listen to their respiration closely. Noises can originate
from the upper (nostrils, trachea) or lower (lungs, air sacs)
respiratory tract.
lungs
air sacs
w
e
12. H e a l t h a n d d i s e a s e
ip
Inhaling
The air sacs inflate as the body cavity expands and air
is drawn from the beak into the posterior sacs. At the
same time, the air that was in the lungs is drawn into the
anterior sacs.
dp
e
ip
dp
in
in
w
anterior air sacs
parabronchi
lungs
bro
nc
hu
s
posterior air sacs
anterior air sacs
parabronchi
lungs
bro
nc
hu
s
posterior air sacs
Exhaling
The air in the posterior sacs is pushed into the lungs,
where gas exchange takes place. The air from the anterior sacs is also exhaled now. This creates a non-stop,
one-way flow of air through the lungs.
181
In the beginning of the infection the ORT affected area
can be clearly distinguished from the healthy lung tissue.
Ornithobacterium rhinotracheale (ORT)
Ornithobacteriosis is an acute, contagious respiratory
disease, the course and duration of which depends on
such factors as climate, stocking rate and other simultaneous infections. ORT can (re)cycle between farms and
houses and is a major problem on multi-age sites. Signs:
coughing, sneezing and reduced weight gain. Sinusitis
and conjunctivitis are common symptoms. Infections are
seen in 2-week-old birds, but the most severe lesions
show in older birds (>14 weeks). Mortality rates range
from 2-11%. In turkeys of 12 weeks of age or older ORT
can cause acute mortality rates of up to 50%. Although
ORT is said to be a respiratory pathogen, due to its’ distribution with the blood it can be isolated from the heart,
liver, joints, brain and bone marrow. Bacteria such as E.
coli, Bordetella avium, Mycoplasma sp, and Pasteurella
sp. can trigger ORT infection. Within the turkey house it
is likely to be transmitted by aerosols, direct contact and
drinkers. The sensitivity of ORT to antibiotics is highly
variable. Prevention is based on good hygiene, therapy
and vaccination.
A typical one-sided lung infection by ORT, accompanied
by other bacteria.
Nasal discharges can cause wood shaving to stick into
and completely block the nostrils.
182
Swollen sinuses (one/two sided), nasal discharges,
inflammation of the eyelids (conjunctivitis), sometimes
leading to blindness, can indicate clinical TRT.
Turkey rhinotracheitis (TRT)
Rhinotracheitis in turkeys is an economically important
disease caused by avian metapneumovirus (aMPV).
The disease may manifest itself more as a rhinitis than
a tracheitis, and the virus can replicate in reproductive
organs. Infected turkeys can show the symptoms of
sneezing, snicking, rales and head shaking. There is a
nasal discharge, foamy conjunctivitis and swelling of
the sinuses. Some birds develop pus cores within the
infraorbital sinuses, large numbers of Escherichia coli and
other bacteria being present. This can lead to mortality,
especially in poults.
Morbidity is frequently 100% in flocks that have not
been vaccinated or previously infected. Mortality may
vary between 3% and 15%. Mortality can also occur in
vaccinated flocks, depending in part on the nature of the
bacteria present and environmental factors (poor ventilation, high levels of ammonia and dust) that enhance
infection by these secondary pathogens. Surviving birds
recover within 10 to 12 days.
Vaccination is the main form of control in countries where
aMPV infection is widespread.
Turke y S i gnal s
Aspergillosis (brooder pneumonia)
Aspergillosis is usually caused by Aspergillus fumigatus.
It most commonly affects poults from 5 days to 8 weeks
of age, although it can affect older birds. Indicators of
infection include heavy or rapid breathing and yellow or
grey nodular lesions in the respiratory tract, especially
lungs and air sacs, and occasionally in the mouth or
trachea. Lesions are common in the eyes and can sometimes occur in the brain. They occur when poults inhale
fungal spores at the hatchery or brooder house.
Spores are present in almost all litter materials and
grow at room temperature (-20°C/70°F) or warmer. The
consequences of using molded litter can be very costly:
aspergillosis outbreaks in poults can lead to tremendous
losses: 2-3% per day.
It is important to locate the source of fungal spores
causing the infection. Eggs that are washed, dipped
or allowed to sweat due to rapid temperature swings
provide an opportunity for introduction of spores through
the protective surface of the eggshell (cuticle).
Adding ‘fresh’ litter to a poultry house while young birds
are present can expose these birds to a high concentration of aerosolized fungal spores.
There is no practical cure for infected birds. Cull them.
Raising the humidity and eliminating the source of the
infection will limit the spread of the disease. Spraying the
litter lightly with an oil-based germicide will help. Control
dust and movement of spores. Replace litter if highly
contaminated and do not use litters materials high in
bark content or ones that have previously been wet.
Bordetella (turkey coryza)
Bordetellosis is a highly contagious upper respiratory
tract disease caused by Bordetella avium. The disease
primarily affects young turkeys. Bordetellosis occurs in 2
to 6-week-old poults. The disease is characterized by its
sudden onset and rapid spread with high morbidity (80 to
100% in 36-72h) and low mortality. The first clinical signs
include foamy conjunctivitis, sneezing and coughing, with
moist tracheal rales, but these signs are not specific for
bordetella. In older turkeys, the only sign is a dry cough.
New signs are observed during the second week after
the onset of the disease. The exudate becomes progressively thicker, crusted, brown, soiling the nostrils and the
feathers of the head and shoulders. Some poults may
show dyspnea, open-mouth breathing and the voice of
affected poults may become high-pitched. Submandibular edema is commonly noted. Diagnosis of bordetellosis
is partly based on its sudden appearance and rapid
spread in young turkeys.
12. H e a l t h a n d d i s e a s e
Aspergilloma in the poult’s brain.
Severe aspergilloma in the air sac
cavity of an older turkey.
Gasping for air, a typical symptom. At
an early stage you can notice intensive
head shaking. It becomes obvious
very quickly if the problem has spread
through the flock.
Lungs with white spots (fungal colonies).
With a bordetella infection you can
see exudate by pressing the nostrils.
Open-mouth breathing and clear
swelling under the beak (submandibular edema).
183
Mycoplasma-related diseases
Mycoplasma bacteria may be the cause of several types of diseases in turkeys and other bird species. There are several strains
of Mycoplasma bacteria, but those of primary concern are M. gallisepticum, M. synoviae, M. iowae, and M. meleagridis. Outbreaks
of disease caused by these organisms result in a variety of symptoms and bring about poor growth rates and egg production,
along with possible flock morbidity and mortality. Mycoplasma organisms can survive only for a few days outside the bird on
feathers, clothes and hair. Once a flock is infected with this disease, the best course of action is to depopulate the farm and
then clean and disinfect everything. Have a down time of at least 2 weeks and then restart production.
Swollen sinuses look very similar to
TRT or bacterial respiratory infections.
By gently pressing on the sinuses
you can squeeze out the exudate.
Swollen joints can be signal of synovitis. You can best assess the extent of
unilateral swelling by comparing two legs. If both legs are affected, such birds
rarely stand on their feet.
Swelling above the right hock joint is obvious in this lame bird. The joint is
large, hot and the blue skin discoloration is seen on the unfeathered part of
the skin.
184
Infectious Sinusitis
Infectious sinusitis is a turkey disease caused by
Mycoplasma gallisepticum — the same organisms
that cause chronic respiratory disease in chickens.
The disease is also found in pigeons, quail, pheasants,
ducks, and geese. Coughing, sneezing, and a thin nasal
discharge usually occur preceding the appearance of the
swollen sinus. The swollen sinus is soft at first but may
become hardened as the disease progresses, usually after secondary infections with other bacteria. In the lower
respiratory form, the disease may present itself through
coughing, sneezing, and gasping. Air sac infection may
be in evidence on postmortem examination. The disease
is spread through contact with contaminated birds or
materials. The disease will pass into eggs from infected
hens. The organism can survive a few days outside of
the bird’s body and within the eggs for longer periods of
time. Recovered birds remain carriers of the disease. Diagnosis can be made by blood testing or PCR. Obtaining
poults from Mycoplasma free flocks is the best prevention for this disease. Dispose of Mycoplasma-positive
flocks, as infected birds always remain carriers.
Synovitis
Synovitis is a worldwide disease of turkeys caused by
Mycoplasma synoviae. It is frequently complicated by
additional bacterial infections. There are two forms:
1. The respiratory form infects the trachea, sinuses, and
air sacs and is more often found in broiler chickens.
2. The systemic form affects the synovial membranes of
joints and tendons and is found in both turkeys and
chickens.
The systemic disease usually appears in turkeys at
10-12 weeks of age. Lameness is followed by lethargy,
reluctance to move, swollen joints, loss of weight, breast
blisters, poor growth, variable respiratory signs and
lesions, and yellow, creamy fluid in swollen joints (hocks,
wings, and feet). Chronically infected birds become
dehydrated and emaciated. The most common means
of transmission of synovitis is through infected breeders. Poor sanitation and management practices also
contribute to the problem. It also spreads bird-to-bird at
hatch and thereafter. Birds are infected for life and remain
carriers. Mycoplasma are sensitive to sunlight and disinfectants. They are spread via equipment, clothing, etc.
Antibiotics yield some results, and they should be given
by injection or in the drinking water. Some producers
prefer to give antibiotics by both methods simultaneously,
though this can result in difficulty in managing dosage
levels. Always obtain poults from Mycoplasma-free
breeders as no medication will eliminate the organism
from the flock once they have it.
Turke y S i gnal s
Sudden death and infectious
diseases with high mortality
Some diseases and disorders lead to a sudden death
of many birds. These are mainly related to disorders of
the cardiovascular system and acute viral infections.
Many cardiovascular diseases are important causes
of death in poultry: dilated or spontaneous cardiomyopathy (round heart disease), aortic rupture, sudden
death syndrome and ascites.
Examples of sudden death:
•
•
•
•
•
•
•
•
•
Aortic rupture
Round heart disease
Erysipelas
Highly Pathogenic Avian Influenza (AI)
Newcastle disease, velogenic viscerotropic (vvNCD)
Colisepticemia
Perirenal hemorrhage
Pasteurellosis
Blackhead
Cardiovascular disease: roundheart
If you find an enlarged heart there may be straw-colored
fluid in the pericardial sac and abdominal cavity. Turkeys
with round heart appear stunted and may show labored
breathing. Together with the enlarged heart, the liver may
also be enlarged and the abdominal cavity can contain
straw-colored fluid (ascites). Cardiovascular disease
results in higher mortality and reduced performance,
especially between two and three weeks of age but is
not limited to these time periods.
The round shape of the heart is
clearly visible (right).
Round heart disease with dilated
right ventricle.
Aorta rupture.
Perirenal hemorrhage.
Aortic rupture and perirenal hemorrhage
Aortic rupture and perirenal hemorrhage are characterized by sudden death mostly in fast growing toms.
It occurs between 7 and 24 weeks of age. The highest
mortality usually occurs between 12 and 16 weeks and
in most flocks usually reaches 1-2%. Mortality as high
as 20% in a span of a few weeks has been observed in
some turkey flocks. Nutritional imbalances are suspected
to cause malformation of the elastic vascular wall which
may then rupture under high blood pressure situations
(stress, acute alertness, fights, etc.).
Erysipelas
Erysipelas is caused by the bacteria Erysipelothrix rhusiopathiae. It not only causes death in the flock, but also
infertility in the male. For humans it is dangerous, since
it is a zoonosis. A sudden outbreak is a characteristic of
all infected birds, whatever their age. Toms are predominantly affected. Many birds will have no clinical signs and
may be found dead, but some will have an unsteady gait
and appear weak beforehand. A dark, purple, swollen
snood is commonly seen in affected toms. The bacteria
are transmitted by contaminated material, entering the
bird via defects of the mucous membrane or skin. Fish
or fishmeal has been cited as the most likely causes of
infection in turkeys. The bacteria can also be transmitted
in the semen of the tom. Husbandry measures such as
rotating turkeys from contaminated areas and disinfecting
equipment with 1-2% sodium hydroxide is recommended. It can be treated with antibiotics and vaccination
(erysipelas bacterin) is also available.
Colibacillosis
Avian colibacillosis (or colisepticemia) encompasses a
number of different infections
caused by avian pathogenic
Escherichia coli (APEC). The
disease has a worldwide
distribution and all poultry
species are susceptible to
infection. Decreased immunity
due to other infections and/
or over exposure due to poor
environmental conditions are a
main cause. The many forms
of colibacillosis are the most
frequently reported bacterial
diseases of commercial poultry
flocks and are responsible for
significant economic losses.
A severe case of Colisepticemia (E.coli
poliserositis), involving all internal organs
(heart, spleen, liver, intestines).
185
Avian Influenza (AI)
AI is caused by a virus. Almost all birds are susceptible,
especially turkeys. One type, H5N1, can be especially severe and under certain circumstances can infect
humans. Mild forms produce listlessness, respiratory
involvement, diarrhea and low mortality in birds. Some
infected birds show no symptoms. Acute forms produce
facial swelling, cyanosis, dehydration and respiratory
distress, lesions and small hemorrhages throughout the
body, along with high mortality rates. Poor sanitation or
farm biosecurity, and close contact with wild birds (especially migratory waterfowl) will increase the chances of
exposure to AI. Large amounts of virus are excreted from
gastrointestinal and respiratory tracts and remain viable
for variable lengths of time depending on environmental
conditions. Notify disease regulatory officials if AI is suspected. Flocks confirmed with AI should be depopulated.
Avian influenza causes a very high level of mortality. This is an image you can
expect to see within one day.
With AI you will find hemorrhages throughout the body. Here there is a severe
hemorrhage in the pancreas and duodenum.
An enlarged spleen.
186
Hemorrhages on the heart (pericardium).
Turke y S i gnal s
Newcastle Disease (NCD)
Newcastle disease is an acute and highly contagious
viral disease found in all bird species. Newcastle spreads
rapidly through the flock, and causes high mortality in
young flocks. Signs of the disease are gasping, coughing, hoarse chirping, increased water consumption, loss
of appetite, huddling, partial or complete paralysis of
the legs and wings, and holding the head between the
legs or on the back with the neck twisted. Postmortem
examination may show congestion and hemorrhages in
the gizzard, intestine, and proventriculus; cloudy air sacs
may also be seen. Large amounts of NCD virus are shed
by infected birds in their droppings and in droplets from
the respiratory tract, especially during the viremic (virus
in blood) stage (5-7 days). Air-born virus (droplets or
dust particles) can then be directly inhaled or ingested by
other birds and can contaminate litter or other surfaces.
Humans and their equipment most often transfer infectious material: very small amounts of manure carry large
amounts of virus. The virus remains alive in litter for up
to 2 months and in dead carcasses for up to 12 months.
The virus is destroyed by heat, direct sunlight, disinfectants, and fumigants.
There is no effective treatment, though antibiotics are
normally given to limit secondary infections.
Vaccines are available for use in turkeys. On a mass
basis, the vaccine can be given to the birds in drinking water or in the form of a mist or spray. Follow the
manufacturer’s recommendations when using these
products and conform to the vaccination program that is
recommended for your area.
Holding the head between the legs or on the back with neck twisted is a
symptom of NCD.
Cecal tonsils are always involved in case of an enteric
viral infection, like HPAI, vvNCD or HE.
In flocks with acute viral infection with NCD, these kind of droppings with
green bile content can be seen.
Hemorragic ‘belt’ between the gizzard and proventriculus
is a symptom of a vvNCD.
Partial or complete paralysis of the legs and wings is a symptom of NCD.
12. H e a l t h a n d d i s e a s e
187
CHAPTER 13
Vaccination
Vaccination is a way of stimulating the immune response of the bird to fight incoming infections. But if
your hygiene levels are poor, vaccination alone won’t be enough. If birds are overwhelmed with disease
organisms, even flawless vaccination will eventually fail!
The efficiency of any vaccination in the poultry
industry depends predominantly on the coverage
of the flock (% of vaccinated birds) and uniformity
of vaccine administration (doses per bird). When
there is a choice, live vaccines have the quickest impact. Killed vaccines deliver a slower, but
stronger and longer lasting immune response.
Remember, only a healthy flock should be vaccinated, unless it is an emergency vaccination to
stop a huge disease outbreak.
Often a spray vaccination is done at arrival, just before emptying the boxes.
188
Turke y S i gnal s
Timing
Hen
Breeder hens pass protection against a number of
diseases to their day-old poults via maternal antibodies in the egg yolk. These protect the poults
against disease for a few days/weeks.
For example, most maternal antibodies against
Hemorrhagic enteritis (HE) disappear by 4-5 weeks
of age, but if you vaccinate too soon, it will not
take effect because the maternal antibodies will
neutralize the vaccine. If you vaccinate too late,
the poult will be temporarily vulnerable to a field
virus (immunity gap). You can base the timing of
vaccination on a blood sample analysis taken from
day-old poults (18-25 samples). When poults originate from two breeder flocks it is difficult to determine the correct vaccination timing, some of the
group might have to be vaccinated early whereas
others should be vaccinated late. Therefore, limit
mixing eggs/poults.
Result = mother + own
Resistance
Lowered
resistance
Minimum desirable level
Immunity
via hen
Own immunity
Age (Weeks)
Maternal immunity decreases gradually, but before a vaccination has an effect there
might be a short period with reduced immunity. This is called the immunity gap.
Factors influencing choice and application of
vaccine
•
•
•
•
•
•
•
•
Governmental regulations
Epidemiological situation
Cost benefit analysis
Availability of the vaccine
General level of immunity required
Infectious pressure at farm or region level
Immune status of birds
Vaccination programs for other diseases
Diseases turkeys can be protected against by vaccinations
Virus
Bacteria
Target tissue
Protozoa
Systemic
Turkey rhinotracheitis (TRT)
X
Newcastle disease (NCD)
X
X
APMV-3
X
X
Hemorrhagic enteritis (HE)
X
X
Avian Pox (AP)*
X
X
Avian Encephalomyelitis (AE)
X
Avian Influenza (AI)
X
Respiratory
Type of vaccine
Articular
X
Live
Killed
Ocular/
spray
X
X
Bordetella avium (BA)
X
X
Pasteurella multocida (PM)
X
X
Escherichia coli (E.coli)
X
X
Salmonella spp.
X
X
Erysipelothrix rhusiopathiae
X
X
Mycoplasma gallisepticum (MG)
X
Mycoplasma synoviae (MS)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Injection
X
X
X
X
Water
X
X
X
Application method
X
X
Ornithobacterium rhinotracheale (ORT)
Eimeria spp.
Enteric
X
X
X
X
* AP is vaccinated in the wing-web
Agent origin
Infection
The possibilities for vaccination varies between regions and countries due to differences in legislation, disease pressure and vaccine availability.
13. Va c c i n a t i o n
189
Injection in the hatchery
Injection of killed vaccines in the hatchery to dayold-poults should be performed by trained personnel with multiple dosing syringes or by automatic
injectors. Operators and equipment must be carefully trained and closely supervised.
Successful vaccination: all the load is under the skin.
It is very easy to identify a failed vaccination if you use a
blue dye for each vaccination.
Automatic systems save labor costs, but require capital
investment, accurate adjustment, control and maintenance. Replace the needles after every 10,000 poults.
Always check some poults to confirm the injection was
successful. If there is a noticeable number that have not
been performed then readjust the equipment, clean the
piping, and change the needles more regularly.
The equipment for semiautomatic vaccination is cheaper, but requires more operators. The result depends not on
automation, but people.
190
Turke y S i gnal s
Injection in the turkey house
Killed vaccines must be injected into each bird
using semi-automatic manual injectors.
There are two major injection methods for older
birds to allow suitable vaccination:
• Intramuscular (IM) – into the muscle
• Subcutaneous (SC) – under the skin
Avoid this area!
cloaca
The tail head is the most common place of intramuscular
injection in turkeys. But is has to done with care.
Vaccination in the turkey house is a very labor and timeconsuming process, which is also highly stressful for the
birds. For greater efficiency the injection can be combined with an eye/nose drop vaccination. Remember:
‘Quality is more important than speed!’
injection
in the wingweb
neck
Correct subcutaneous injection in the neck.
leg
tailbase
breast
(not applied
in commercial
turkeys)
inguinal fold
Incorrect subcutaneous injection. The injection
was placed in the jugular vein, causing a major
bleed.
13. Va c c i n a t i o n
Several sites are available for each type of injection. Take into consideration:
ease of application, reaction at the injection site, and human safety. Comparisons
should be made to decide which injection site gives the best result for an individual operation.
191
Eye/nose drop vaccination
The eye-drop/nose-drop method (intraocular/intranasal) is the most effective method.
A special bottle of 30 ml guarantees a standard
droplet size of 0.03 ml (enough for 1,000 poults).
To prevent the solution from getting warm in the
hands of the vaccinator, use multiple bottles and
alternate their use while keeping the others in an
iced cool box.
The vaccination will only be considered successful if the drop (0.03 ml) is placed
into the eye or nasal cavity and absorbed. For this to occur, it is important to wait
a bit after administering the drop, before releasing the bird.
If the eye/nose drop vaccination is done correctly you will
see the blue dye on the tongue.
Nose-drop vaccination
Do not touch the poult’s eye with the vaccine bottle, the droplet should hang freely, which guarantees the correct size of the droplet and vaccine dose per poult.
192
A transparent vaccine solution gives you less possibility of
quality control.
Turke y S i gnal s
losses by
DRIFT
Spray vaccination
The spray method is the preferred method for
mass vaccinations against respiratory diseases
because it induces a powerful systemic immunity
(antibodies in blood stream) and local immunity
on the mucous membranes of the eye, and upper
respiratory tract (Harderian gland). Local immunity in the upper respiratory tract is important
in early protection following TRT and NCD vaccination. Spray vaccination can be carried out by
either coarse or fine spraying. The particle size is
determined by the combination of nozzle type and
pressure. Crucial when applying spray vaccination
is the uptake of the vaccine droplets by the poults.
Droplet size and consistency of application are
important in establishing the highest success rate.
Besides manually pumped knapsack sprayers,
electric rechargeable knapsack sprayers are available. The advantage of electric sprayers is that you
can administer a lot of water in a short time without any effort.
losses by
EVAPORATION
Jet
emitted
losses by
SETTLEMENT
Useful
fraction
Between emission from the sprayer and contact with the bird, the vaccine
suspension is subject to losses: settlement, evaporation and drift. The part of
the spray droplet, which reaches the bird, is called the useful fraction.
Spraying plan
Draw up a spraying plan to ensure that no areas are left out. Divide
the house into 2.5-3-meter-wide strips using drinker and feeder lines
as reference points for the direction of walking and spraying. Overlaps
of spraying are no problem, but if certain areas are only half sprayed,
this influences the results.
Keep your spraying equipment in order. Any broken element can lead to vaccination failure.
Switch off the lights, put on the head-torch and spray all
the flock by slowly moving through the house and aiming
the nozzles and the birds’ heads. This practice keeps the
birds in place during vaccination.
13. Va c c i n a t i o n
193
Fine spraying
The impact of fine spraying is both direct and indirect. Numerous small droplets remain suspended
in the air and are breathed in by the birds. To limit
losses by evaporation, the spray must be aimed
approximately 50 cm above the birds’ heads in
order to surround them with a mist. Due to the
indirect impact, it is not as essential to group
the birds together as it is for coarse spraying.
Numerous small droplets will enter the trachea,
the bronchi, the lungs and even the air sacs. They
are responsible for stimulating a powerful immune
response but may cause post-vaccinal reactions
in birds with less than perfect health or carrying
potentially pathogenic organisms like E. coli, mycoplasma and ORT.
Coarse Spraying
Coarse spraying is recommended for day-old
vaccinations in the hatchery or on the farms and
for the first priming vaccination. The Impact of
coarse spraying is direct. A coarse spray doesn’t
allow the virus to be inhaled too deep (which
can cause problems). Bigger droplets which have
fallen on the shoulders are taken up into the eyes
(Harderian gland) when the head is wiped on the
shoulders.
Aerosol vaccination
Very fine spraying ensures that the vaccine virus
penetrates more deeply into the birds’ respiratory system. Aerosol vaccination is applied with
an atomizer. This method can be used for TRT
vaccinations and for the second and subsequent
ND vaccinations. It is not suitable for the first ND
vaccination.
A knapsack sprayer is the most common way to apply a
course spraying.
By using a blue dye in your vaccine solution it is very easy to evaluate the
size of the droplets and the flock coverage achieved by the vaccine.
194
Adjust the vaccination procedure (spraying regime, walking speed) with the lights on.
Turke y S i gnal s
Spray vaccination in the hatchery
In many areas, poults are vaccinated with live
vaccines using a spray cabinet that administers
a defined amount of water-borne vaccine to each
box of poults. The droplet size is carefully con-
trolled and vaccination can be seen on the poults
as either moisture or dye. This method is typically
used for respiratory vaccines (TRT, NDV) and live
coccidiosis vaccines.
A spray cabinet.
Applying a spray vaccination in the hatchery with a knapsack sprayer is an alternative to the spray-cabinet.
Test your droplet size by spraying an empty poult crate
with a paper.
The fine droplets on the heads of the poults are an indication of correct application.
Correct
Incorrect
Make sure the equipment (filters, o-rings) is clean, both inside and out. Use a filter to prevent any sediment and other impurities from
getting into the spray and blocking the nozzle.
13. Va c c i n a t i o n
195
Drinking water vaccination
How much vaccine solution is needed for
drinking water vaccination?
•
•
•
Check the amount of water consumed by the flock in the
previous day
Divide that by the hours of light in the turkey house
Multiply the result by 2 hours of required vaccination time
Example:
• The flock consumed 2,000 liters of water
• 2,000/17 (hours of light) = 118 liters (water consumed per hour)
• 118 * 2 = 236 liters
• 236/100 = 2.4 liters of vaccine stock solution is required to put
through the house medicator, set at 1%
All turkeys need to drink, so drinking water vaccination is a good method to reach all turkeys. All
medication, disinfectants and chlorine must be
removed from the drinking water 48 hours before
vaccination. Wash the drinkers the day before vaccination.
Always administer the vaccine in the water early
in the morning. To make sure that all the turkeys
drink simultaneously and obtain the vaccine,
water is withdrawn a short period before vaccine
administration: 30-60 minutes in hot climates or
60-90 minutes in cool climates.
Once the drinkers are in place again, walk through
the house every 20-30 minutes to check if the
birds are all drinking water. If using hand drinkers,
redistribute drinkers if necessary. The birds must
drink all the vaccine solution in no more than two
hours, and never in less than one hour.
Proper vaccine preparation
196
1. Only use vaccine that has been
properly stored in a cool, dark place.
2. C
heck the dose on the pack. Similar
looking bottles may contain different
doses. Vaccinate at the right age:
incorrect use of vaccine can cause
severe reactions such as rhinitis,
delayed growth or diarrhea.
3. U
se a measuring jug (used solely for
this purpose), and rinse it again before
next use. Residues of substances such
as disinfectants can destroy the vaccine.
4. F
ill the measuring jug with clean, cold
water.
5. U
se skimmed milk or commercially available vaccine protector. This binds harmful molecules such as chlorine or iron in
mains water, keeping the vaccine more
effective. Mix well with the water in the
measuring jug using a whisk.
6. O
pen the bottles of vaccine under
water: the vacuum in the bottles will
draw the water into the bottles at high
speed, mixing the contents to form a
solution. Mix well with a whisk to create
a homogeneous stock solution.
Turke y S i gnal s
Water vaccination and behavior
Consider that even after 2-3 hours of thirst not all
the turkeys will rush to the drinkers. Many birds
are disinterested in drinking and still walking
around or eating. Therefore vaccine take-up will
be very poor with just a one stage vaccination. It
would be more efficient to administer the drinking
water with vaccine by hand in the drinkers to be
sure every bird gets its vaccine dose! The manual
action stimulates their curiosity. This means you
have to cut off the water and clean the drinkers.
Then you raise the drinkers above the birds and
fill them all with stabilized vaccine solution. Lower
the drinkers and all the birds can then drink at the
same time. Afterwards you keep on distributing
the water with vaccine by hand over the drinkers
until the total amount of solution is finished.
If this is not achievable/practical you have to be
very sure that all birds have had the opportunity
to drink water with vaccine by administering the
vaccine long enough. But not too long; 2 hours
maximum for 50% of the dose. Repeat it with the
second half of the dose immediately after the first.
For hygiene reasons, but also for your own safety, always
wear gloves. Open the vaccine ampoule under water.
Dirt in the drinkers will decrease the effect of the vaccination. If you are using bell drinkers, wash them thoroughly
WITHOUT any disinfectant. This vaccination can be considered a failure.
Fill the line up and put the drinkers down to the level of
the birds’ backs. The colorant clearly shows there is a
vaccine in the drinkers. Let the poults have full access to
water to dip their beaks and nostrils in the vaccine.
13. Va c c i n a t i o n
If you can raise the drinkers automatically, fill them up with vaccination
solution, wait a bit and lower them all at the same time, you are sure
every bird will have drunk from it.
197
Index
air distribution
70, 71
65, 68
air pressure
air quality
62
60, 61, 71
air temperature
air velocity/trajectory
69, 71
alternative systems
31
15, 16, 181
anatomy
antimicrobal growth
promotors (AGP)
168
185
aortic rupture
aspergillosis
80, 183
astrovirus
173
avian influenza (AI)
186
BCO
178
42
beak treatment
beard
18
22, 62, 147
behavior
biofilm
56, 102
biosecurity
46
54
bird control
blackhead
170
bleeding
159
bordetella (turkey coryza) 183
breast
blisters/buttons
144, 157
breeding
10
brooder ring
107
brooding period
106
47
buffer zone
158
cachexia
candling and break-out
35
20
caruncles
catching
153
cecal droppings
161
143
cellulitis
claw treatment
43
47
clean zone
55
cleaning
climate
58
Clostridium
165
CO/CO2
63
coanda effect
69
166
coccidiosis
coccidiosis vaccination
169
colibacillosis
173, 185
communication
21
cooling systems
76
crooked, curled toes
180
crop mycosis (candidiasis) 173
crop
16, 90, 158, 173
crumb
89, 90
culling
114, 133, 140
curiosity
23
darkling beetle
50, 53
day-old poults
32, 114
dead bird storage
47
development 10, 11, 17, 137
diagnosis
176
digestive tract
16
dirty zone
47
174
disease
disinfection
55, 57
198
6
domestication
drinker
110, 127
drinking water
vaccination
196, 197
161, 162, 163
droppings
dry cleaning
55
drying
57
dust
64
dust bathing
25
dysbacteriosis
165
E.coli
144
34
egg shell temperature
egg storage and transport 33
Eimeria
166, 167
electrolytes
98
35
embryonic mortality
equipment
49, 129
erysipelas
185
euthanasia
141
192
eye drop vaccination
farm blindness
13
48
farm entrance
farm location
47
fat deposition
151
fats
98
151
fatty liver
feathering
9, 19
fecal droppings
161
feed
88
95
feed safety
feed structure
91
feed withdrawal
133, 152
110, 124, 125
feeder
feeding program
89, 146
femoral head necrosis
178
fines
91, 92
89
finisher feed
flip-overs
116
123, 139
flock inspection
60, 108
floor temperature
flushing
104
foot pad dermatitis 143, 179
fractures
157
gastrointestinal
tract/GI tract
16, 17
grit
99
89
grower feed
grow-out
136
gut development
17
gut health
160
gut infection
164, 165
handling
26, 27
hatchery
32
hatching
36
health
174
heat stress
61, 142
heater
77, 107
heating systems
73, 74, 75
156
hemorrhages
hemorrhagig enteritis (HE)171
heritage turkeys
9
histomonosis/hisotomoniasis 170
142
house temperature
huddling
118
169, 189
immunity
incubation
32
infectious arthritis
179
infectious sinusitis
184
infertile
35
injection
190, 191
inlets
71, 72
50, 53
insect control
insulation
66, 67
intoxication
92
98, 177
leg problems
Liebig’s law
88
77
lighting
litter eating
99
litter management 78, 85, 86,
87, 109
litter materials
81
litter quality 84, 121, 143, 144
79
litter storage
liver degeneration
151
134, 135, 153
loading
market trends
8
7
meat
microbiota
17
microclimate
59
66
minimum ventilation
89
mini-pellet
moisture content
17, 83
97, 125
molds
mollier diagram
61
137
mortality
mycoplasma
184
mycotoxins
95, 96, 97
22, 24
natural behavior
172
necrotic enteritis (NE)
negative pressure
68
Newcastle disease (NCD) 187
NH3
64
nose drop vaccination
192
NSP
98
nutritional disorders
98
observation
13
ORP
105
ORT
182
pecking
131, 148, 149, 150
pellet
90, 91
pendulous crop
90
pendulum drinker
112
perirenal hemorrhage
185
perosis
179
phase feeding
88, 89
physiology
20
piling up
28
plumage
18
45, 115
poult delivery
poult distribution
118
poult enteritis complex
173
poult harvesting
37
poult quality 37, 38, 40, 120
poult temperature
113
poult transport
113
37
poult yield
preening
25
29
production systems
proteins
98
protozoan infections
173
pseudomonas
101
rearing period
122
recovery/sanitary pen
117
61
relative humidity
respiratory problems
181
rice huls
81
rickets
98, 178
50, 51, 52
rodent control
rotavirus
173
roundheart
185
173
salmonella
sanitary lock
49
82
saw dust
segregation
92
senses
13, 21
130
sensors
setting
34
sexing
41, 138
signals
11
skin damage
159
slaughterhouse
155, 156
snood
14, 20, 44
splayed/spraddled legs 38, 117
spray vaccination 193, 194, 195
89
starter feed
stocking density
30
163
stomach content
straw
81, 83
stress
174
strutting
24
sunning
25
supplementary feeder
119
179,184
synovitis
target weight
93
tibia
dyschondroplasia (TD) 178
transfer and transport 132, 154
TRT
182
vaccination
169, 188
ventilation
58, 65
vermin
50
water
88, 100, 128, 145
water line disinfection
56
water quality
101, 105
water sanitation
103
water spillage
127
20
wattles
weighing
132
wet droppings
17, 165
84
wet litter
whole house brooding
107
whole wheat
94
wood pellets
81
wood shaving
81, 82
Turke y S i gnal s