National Organic Standards Board

Livestock Committee

Proposed Discussion Document

March 28, 2012

Guidance for Assessing Animal Welfare on Organic Poultry Operations

The following is provided to aid in assessment of whether or not the requirements of § 

205.238-241 are being met sufficiently to demonstrate adequate animal welfare conditions on 

organic poultry operations. In addition, this document provides further guidance to producers 

for improving poultry welfare. The internationally recognized “five freedoms” (freedom from 

hunger, thirst and malnutrition; freedom from fear and distress; freedom from physical and 

thermal discomfort; freedom from pain, injury and disease; and freedom to express normal 

patterns of behavior) promulgated by the Farm Animal Welfare Council are a useful 

framework for considering animal welfare.

Nutritional requirements 

Poultry must be fed a wholesome diet that meets their nutritional needs and promotes optimal 

health. Feed should be formulated to meet or exceed the National Research Council’s 

Nutrient Requirements of Poultry, and adjusted with bird age and stage of production. Feed 

and water should be palatable and free from contaminants. Unless using a commercially 

prepared complete feed, laying hens must have access to a course calcium source, such as 

ground limestone. Water should be fresh, potable, and clean. Feed and water delivery 

systems should be checked daily and kept clean and in good working order. Birds must be 

provided with feed on a daily basis and water should be available continuously, with the rare 

exception of withholding for medical treatment under the advice of a veterinarian.

There should be enough feed and water space to prevent competition between birds. In 

double sided liner feed track, there should be at least 2 inches of feed space per bird, and 4 

inches per bird for single sided feed track. Circular feeders should provide at least 1.5 inches 

of feeding space per bird.

Adjust the height of drinkers for easy access at each bird age and so that droppings do not 

fall into the water supply. There should be at least 1 bell-type drinker for every 100 hens and 

1 nipple drinker per 12 hens. In small flocks, there should be a minimum of two drinkers.

Physical alterations

Management methods should be implemented to reduce feather pecking and cannibalism

(see “preventing injurious pecking” below). If these management strategies fail, therapeutic 

beak trimming using the infrared laser method should be considered for subsequent flocks. 

This amputation must be performed on chicks no later than 10 days of age, and is commonly 

carried out at the hatchery. 

While not pain-free, infrared laser beak trimming is superior to the conventional hot blade 

trimming in that open wounds are eliminated and the method is more precise, minimizing

error and inconsistency. It also leaves a greater proportion of the beak intact.1

 

LC 1 Animal Welfare-Poultry
With the exception of toe trimming of turkey poults at the hatchery using infrared laser, other 

alterations including de-snooding, caponization, dubbing and toe clipping of birds are not 

permitted.

Force molting

Forced molting by feed withdrawal is not permitted under the National Organic Program, as it 

causes hunger and distress. If force molting is practiced, a molt ration should be supplied 

that is palatable and acceptable to the birds. A molt diet is acceptable to the birds if, on 

average, the total amount of feed consumed per day does not differ during the molting and 

non-molting period. Flocks should be carefully monitored during a molt, and individual hens 

that are not faring well should be separated into a designated sick pen and provided with a 

non-molt diet. Water should never be withheld for molting purposes.

Poultry health

Poultry should be monitored for signs of stress and disease. Birds should have a healthy

body condition, have good feather cover for their stage of life, and no more than 2% should 

have poor hygiene, lesions or other injuries. Sick or injured birds must be treated without 

delay or, if suffering and unlikely to recover, euthanized humanely. Producers must not 

withhold medical treatment from a sick animal in an effort to preserve its organic status.

Animal health plan

All poultry farms should draft and follow an animal health plan that covers the specific 

circumstances unique to each farm. The plan should include, at a minimum, the disease 

prevention strategy (such as vaccination schedules and biosecurity protocols), contingency 

plans for emergency situations (including failure of the power or water supply), predator 

exclusion steps, veterinary contacts and emergency euthanasia procedures.

Sick pens

A designated area for the treatment of injured or moribund birds should be prepared to aid 

recovery, by preventing competition between birds and allowing a greater level of individual 

care. Sick pens should be arranged for the comfort and safety of the birds during 

convalescence. Feed and water must be provided, with the rare exception of withholding for 

medical treatment under the advice of a veterinarian.

Lameness

Broiler chickens, turkeys and ducks are prone to leg problems, including angular deformities, 

tibial dyschondroplasia (TD), and in severe cases, ruptured tendons. These may manifest as 

lameness or more severe mobility impairment.

Gait scoring is a tool that can be used to assess the degree of lameness in a broiler chicken 

flock.

2,3,4

 Randomly score 100 birds individually by viewing their walking ability using the 

following scale:

Score 0. No detectable gait impairment

Score 1. Slight gait defect. Wobbling or uneven gait. 

Score 2. Gait abnormality. Bird has impairment, but will move away from handler when 

approached.

LC 2 Animal Welfare-Poultry
Score 3. Gait abnormality that impairs function. Bird has a limp, jerky or unsteady gait and 

moves away from the observer when approached, but squats again within 15 seconds. Bird 

prefers to squat when not coerced by handler.

Score 4. Severe gait defect. Bird remains sitting when approached or nudged, but can 

stand or walk when placed in a standing position by a handler. 

Score 5. The bird is completely lame and cannot walk. The bird may shuffle along on its 

hocks. 

Gait score tends to worsen as birds age.5

 Birds that are suffering or are too crippled to reach 

feed and water should be humanely euthanized. Birds at gait score 3 and above are 

probably experiencing pain,6,7

 so ideally no birds should reach this level. However, a

reasonable place to set the target for lameness is that 95% of the birds should be gait score 2 

or less at seven weeks of age or older. 

Broiler chickens, turkeys and ducks are also prone to contact dermatitis. When heavy birds 

spend excessive time lying down in wet or soiled litter, they are prone to skin lesions on the 

feet, legs and breast.8, 9,10 Focal ulcerative dermatitis is small skin lesions (commonly called 

“breast buttons”) that develop on the keel bone of turkeys.11 A reasonable place to set target 

levels is that no more than 5% of birds should show hock burn, breast blisters or foot pad 

dermatitis. 

Additional producer guidance on preventing leg problems

While dietary deficiencies are one factor that can lead to skeletal deformities,12 genetic 

selection for rapid early growth rate is the major contributing factor. Rapid growth is also 

implicated in metabolic disorders, including ascites and Sudden Death Syndrome.13 Some 

commercial broiler crosses are more susceptible to leg problems than others,

14 but slow 

growing broiler strains are generally less prone to these weaknesses. They are also less 

prone to heart and circulatory problems.

15 The use of slow growing breeds is therefore 

recommended. Broiler growth should be limited to no more than 45g per day and should be 

achieved without feed restriction.

Other factors that can improve gait score include: increasing the daily period of darkness, 

lowering the stocking density, and adding whole wheat to an otherwise balanced diet. 

Increasing the daily period of darkness allows chickens more time to rest and less time to 

feed. Feeding whole wheat is thought to be effective though slowing the rate of digestion. 

Both of these interventions work through reducing growth rate.16 The reason that higher 

stocking densities can lead to lameness is more complex, involving both lack of room 

available for exercise and movement, as well as factors such as additional ammonia and litter 

moisture.17,18,19

Additional producer guidance on preventing dermatitis

Dermatitis lesions are painful and create a gateway for bacterial infection. Avoid them by 

preventing wet, sticky, or compact litter. Use bedding with good moisture holding capacity, 

such as wood shavings, and keep litter dry (but not dusty), with good ventilation. Drinkers 

should be monitored to ensure they are not spilling over and causing wet areas in the litter. 

Water nipples with drip cups can reduce water spillage.

20 Moisture and temperature of the 

litter increase with stocking density, so if these variables become problematic, it may be 

LC 3 Animal Welfare-Poultry
necessary to raise fewer birds in the allotted space.

21 Manually turning the litter can help. 

Floor heating systems have also been found to improve litter quality.22

Conversely, well-managed litter is a soft substrate, while outdoor environments can cause 

abrasion and foot-pad dermatitis if not carefully managed.23 Birds should be kept on 

cushioned, dry, clean surfaces outdoors. Rotate or move birds onto fresh pasture often 

enough to prevent the build up of droppings and damage to the protective vegetative cover. 

Feed composition affects the consistency and composition of bird droppings, and is therefore 

a factor influencing irritant qualities of litter. Protein, fat and salt content can all affect the 

levels of contact dermatitis, as can the source and type of raw ingredients. Within the limits 

of meeting nutritional requirements, adjustments to the diet may help improve litter quality.24

For ducks, bell-type drinkers and open water troughs have been correlated with low levels of 

foot pad dermatitis. Conversely, foot pad dermatitis tends to worsen in houses with nipple 

drinkers. There is also evidence that increasing relative humidity and ammonia levels are 

associated with foot pad dermatitis of ducks.

25

The health status of the flock will also affect the prevalence of contact dermatitis. Intestinal 

parasites, infectious disease, and poor feed quality can cause diarrhea, which will negatively 

impact litter friability (looseness and dryness). Prevent coccidiosis and other enteric diseases 

and feed good quality feed. Also strive to reduce leg problems, as lame birds will sit for 

longer periods of time in contact with litter.26

Varying degrees of foot pad dermatitis on the feet of 

turkeys

LC 4 Animal Welfare-Poultry
Disease 

Disease incidence is a welfare indicator. Respiratory disease may indicate poor air quality. 

Incidence of internal parasites can indicate management issues such as lack of sanitation 

and failure to rotate outdoor areas often enough. 

Poultry houses must be cleaned out completely between flocks if there have been adverse 

health issues with the previous flock; in other cases, the addition of a clean layer of litter will 

help maintain a sanitary environment.

If there is a documented occurrence of a disease outbreak in the region or relevant migratory 

pathway, or state or federal advisory order to confine birds, then poultry must be kept indoors

to reduce the likelihood of pathogen transmission.

Any dead birds must be removed daily and disposed of in accordance with state and local 

laws.

Additional producer guidance on management of disease risk

Disease risk should be managed by using multiple approaches, including attention to outdoor 

range area, good litter management indoors, adherence to an effective biosecurity plan and 

ensuring clean, hygienic facilities. 

Overcrowded and unsanitary outdoor environments are a disease hazard. Providing a rest

period in-between flocks reduces the buildup of infectious organisms and allows the 

regeneration of vegetation and soil. Where stocking density is high, the environmental 

pathogen load may be correspondingly heavy, and bird-to-bird contact will be more frequent. 

Providing as much space as possible is therefore important, and the stocking density

guidelines set out in the organic rule are minimum space allowances—where conditions 

permit, the aim should be to lower stocking densities and provide as much space as possible, 

while balancing freedom of movement with safety of the flock, including protection from 

predators.

Disease risk can be reduced in barn housing by removing droppings (e.g., via a belt in aviary 

systems, for example) or by preventing birds from accessing heavily soiled areas (e.g., by 

placing drinkers on a raised, slatted platform above a manure pit). Contact with droppings—

Foot pad dermatitis and hock burns on a broiler chicken

LC 5 Animal Welfare-Poultry
exacerbated by high stocking density and wet, cool conditions—is a risk factor for enteric 

disease.

27 Litter that “stops working”, leaking drinkers, and an inadequate ventilation system 

(to remove water vapor) may all increase disease risk.28,29 Maintain litter in friable

condition.30,31 Introduce only healthy young birds from genetic lines resistant to intestinal 

parasites.

32

The build up of parasites around the barn can be avoided with the use of mobile housing,33

pasture rotation, reduced stocking density, and by using land with good drainage.34,35 Other 

methods that are helpful include regularly mowing or grazing to keep vegetation short on 

pasture, and removing heavily contaminated soil around the barn before introducing a new 

flock.36 Gravel around the outside of permanent housing structures, by the exits where birds 

tend to congregate, can prevent muddy conditions in wet weather and provide additional 

drainage. 

Biosecurity is a strategic plan to prevent the introduction of harmful pathogens. A good 

biosecurity plan will minimize disease risks and protect flocks. To prevent the spread of 

disease, limit movement between flocks and outside visitors. Always start with the youngest 

birds on the farm when doing daily chores and inspections to avoid carrying pathogens from 

older flocks to younger flocks. Microorganisms, such as coccidiosis for example, can be 

spread on vehicles and equipment, so designate specific tools and equipment for each 

poultry house or farm area. Transport crates should be cleaned between uses. Visitors 

should not enter a poultry farm if they have recently visited other flocks, unless they wear 

protective, disposable outerwear at both locations and ideally change clothes and shoes and 

shower between farms. 

Mortality rates (deaths, culls)

Mortality rate is a key indicator of poultry welfare. Low mortality is also important for the 

economic viability of a poultry or egg production enterprise. A reasonable place to set the 

target for mortality is 3-5%. Birds must be protected from predators.

Additional producer guidance on lowering mortality rates

A low mortality rate is the hallmark of a well-managed poultry farm. Mortality spikes can be 

caused by a number of different problems, including disease outbreaks, cannibalism, and 

excessive losses due to predation. It is vital that producers take steps to prevent each of 

these outcomes, as they are all serious welfare and economic problems.

When poultry are given outdoor access, they become targets for many types of predators 

including coyotes, opossums, hawks, owls, and domestic dogs, to name a few. Predation is 

a welfare issue, as birds may suffer when attacked, are not necessarily killed quickly, and 

flocks can become fearful and reluctant to use outdoor areas if they are threatened by 

repeated attacks. To protect free-range flocks from nocturnal predators, birds must be 

secured in a fully enclosed coop, barn, mobile chicken house or other safe facility at night, 

without fail. Depending on the predator pressure at individual farm sites, further steps may 

be necessary; perimeter fences can be dug deep in the ground to prevent predators from 

digging underneath, and an overhang at the top of the fence will help prevent animals from 

climbing over. Electric fencing can further discourage ground predators, and overhead 

netting may be necessary to protect hens from aerial predators. Do not permit repeated 

heavy losses. 

LC 6 Animal Welfare-Poultry
Preventing injurious pecking 

Injurious pecking, including feather pecking and cannibalism should be managed so that 

severe outbreaks do not occur.

Additional producer guidance on management of injurious pecking

Feather pecking and cannibalism are common behavioral abnormalities of poultry, usually 

most problematic in large flocks of laying hens, but also sometimes seen in other poultry such 

as turkeys, ducks and pheasants. Severe feather pecking can lead to denuded plumage and 

eventually to cannibalism.37,38 Outbreaks of cannibalism are unpredictable, and once they 

begin, are very difficult to stop. Prevention is the best approach.

Beak trimming is commonly used as a prophylactic measure to prevent feather pecking and 

cannibalism. Beak trimming is usually effective in significantly reducing cannibalism and 

subsequent mortality,

39,40 although occasional outbreaks do occur in beak trimmed flocks. 

Beak trimming as a solution is not ideal though, as it is a painful procedure. Further, the beak 

tip is highly innervated and contains abundant sensory receptors;

41,42 cutting off the beak tip 

thus impairs sensory function. Welfare can be improved by controlling cannibalism using 

alternative means. 

Dietary deficiencies have been linked to increased incidence of pecking damage,43 especially 

protein deficiencies,44,45 so the first step in preventing injurious pecking is to ensure that the 

feed is nutritionally complete. However, outbreaks of feather pecking still often occur in 

flocks that are fed to their nutritional requirements. There are a variety of other factors 

involved. 

Successful control of feather pecking and cannibalism requires an integrated approach that 

includes consideration of three main factors: early-life experiences, the environment and 

genetics.46

Feather pecking and cannibalism are not aggressive acts—rather, science demonstrates that 

these are foraging pecks that have been re-directed toward feathers.

47,48,49 In natural 

conditions, domestic fowl spend over 50% of their active time in foraging related activity.50,51 

Studies have shown that hens will choose to forage for feed on the ground in loose substrate 

rather than eat identical food freely available from a feeder.52,53 Thus, the natural urge to 

forage remains strong, even when full feed is provided. The acquisition process itself—

including seeking, investigating, and manipulating feed items—is nearly as important as the 

act of consuming the feed itself.

54 

Pecking preferences are formed early in life, and these are learned through experience.55

Therefore, providing appropriate pecking and foraging substrate from day one56,57 is a critical

factor shaping adult pecking preferences. Scientific research has demonstrated that early 

access to loose litter—such as wood shavings, sand and straw—is an important first step in 

reducing feather pecking, cannibalism and subsequent mortality.

58,59,60, 61,62,63 Conversely, 

studies also show that the absence of loose-litter64 and poor litter quality are risk factors for 

plumage deterioration due to feather pecking.65 Scattering grain or feed into loose litter for 

young chicks can also be beneficial.66 

LC 7 Animal Welfare-Poultry
Lack of perches during early rearing is another important risk factor for feather pecking on 

organic farms.67 Early access to perches can decrease cloacal cannibalism by giving 

potential victims a safe place to avoid hens who would peck them from the floor.68,69,70 Young

birds must learn how to successfully navigate perches by gaining experience with them from 

a young age, which shapes their cognitive spatial abilities.

71 Pullets should have access to 

perches elevated above 35 centimeters at no later than four weeks of age.72,73 Higher 

perches are generally better, 74 although they must be constructed and arranged in a way that 

allows easy access, or else hens can miss a landing, fall and become injured (see section on 

providing perches for laying hens in indoor housing below). 

Feather pecking often begins to appear in affected flocks shortly after moving pullets from the 

rearing to the laying house. When transferring pullets, there are many potential stressors 

including changes in light intensity, diet, house layout and access to the outdoors. Stress can 

be partially alleviated by matching the rearing and laying environments as closely as 

possible.75 Do not change the feed or lighting program at the same time pullets are moved 

into the laying house.

Since cannibalism is thought to have a hormonal basis, the risk of cannibalism may be 

reduced by using lighting programs that delay the age at which hens first begin to lay eggs to

after 20 weeks of age.76 Flocks that begin laying eggs before 20 weeks of age have 

approximately four times the risk for vent pecking as compared with flocks that begin laying at 

a later age.77 

When feather pecking outbreaks occur in adult hens, lowering the light level is a commonly

used intervention. While somewhat effective, the problem with dimming the light is that, like 

beak trimming, the underlying cause of the problem is not addressed. To truly attend to the 

welfare issue, the natural early motivation of a hen to forage and peck should be channeled 

appropriately into desirable adult pecking behavior, as discussed above. 

Feed form is also important for attracting and sustaining foraging related pecks and 

regulating appetite. Studies show that a mash diet is better than pelleted feed for reducing 

feather pecking and cannibalism.78,79 The small particle form takes longer to consume, 

sustaining foraging related pecking behavior for a longer period of time as birds pick out 

individual feed particles.80 A diet high in insoluble fiber has also been shown to help to 

reduce and control cannibalism,

81 and millrun, oat hulls, rice hulls, and lucerne meal are 

effective sources.82 Additional foraging enrichments such as maize, barley-pea silage, 

carrots,83 straw84,85 seeds in suet, and cabbage leaves86 have been shown to attract interest 

and reduce the tendency to perform injurious pecking. 

Most importantly, it has been repeatedly demonstrated in scientific studies that flocks making 

good use of an outdoor range area (where more foraging and exploring opportunities are 

provided for them) are significantly less likely to feather peck and cannibalize flock 

mates.

87,88,89,90,91,92,93 One study found that when at least half the flock was observed 

outdoors during good weather, there was a five-fold decrease in the risk of feather pecking. 

On these farms, it is likely that hens are directing their pecking behavior at appropriate 

foraging substrate, rather than at each other.

94 Therefore it is essential to provide attractive 

outdoor areas and encourage hens to go outside (see section on outdoor access below).

LC 8 Animal Welfare-Poultry
If possible, time the introduction of pullets into the laying house so that they will have good 

weather when the doors are first opened to permit outdoor access. If inclement weather 

prevents them from using the range area when they are young, it may be difficult to 

encourage them out when they grow older.95

Other risk factors that have been associated with injurious pecking include:

• Restricting access to portions of the indoor litter area;

96

• Restricting access to the outside range area;

97

• Changing the diet three or more times during the laying period;98,99

• Using lights inside the nest boxes;100

• Use of bell drinkers;

101,102

• Inadequate number of drinking places;

103

• Reduced indoor temperature (below 68o F);

104

• Not keeping cockerels with the hen flock;

105 and

• Dietary deficiencies.

106

Feather pecking, cannibalism, and the associated mortality have genetic components, which 

means that these traits can be selected against in breeding programs.107,108,109,110 Different 

hen strains vary in their propensity to exhibit injurious pecking behavior.111 It is therefore 

critical to source hens that exhibit low levels of feather pecking behavior. Because breeding 

efforts to control cannibalism are ongoing, it is difficult to pinpoint lasting recommendations 

on specific genetic lines. If a severe outbreak occurs, consider using a different supplier, 

switch to a different hen strain, or use a different breed or hybrid altogether. 

For more information on managing feather pecking without beak trimming see: 

“A guide to the practical management of feather pecking & cannibalism in free range laying 

hens” at:

www.defra.gov.uk/publications/files/pb10596-feather-pecking-050309.pdf

Newberry RC. 2003. Cannibalism. In: Perry GC (ed.), Welfare of the Laying Hen, Poultry 

Science Symposium Series, 27 (Wallingford, U.K.: CABI Publishing, pp. 239-58).

Indoor living conditions

Housing must protect birds from the elements, maintain a comfortable temperature, provide 

ventilation and allow birds to exercise and conduct natural behavior. Cages are not 

permitted. Bedding indoors provides comfort, insulation, and pecking and scratching 

opportunity. However, it must be maintained in clean, dry condition. Slatted-floor systems 

are useful under watering areas to prevent wet litter. 

The indoor climate must be modulated for light, temperature, and air quality to provide a 

comfortable environment for the birds. Lighting should provide for an 8 hour rest period daily. 

Indoor temperatures must not be so warm that birds pant or so cold that they huddle 

together. Ventilation must be adequate to prevent the buildup of ammonia. Ammonia levels 

should generally be less than 10 ppm. Ammonia level testing must be documented and 

ammonia levels must be at or below 25ppm. General levels can be tested using ammonia 

test strips and if excessive ammonia is noted a second test using passive dosimeter or gas 

detection tubes should be conducted. Dust should also be kept to a minimum.

LC 9 Animal Welfare-Poultry
Layers should be provided with nest boxes—at least one box per 5 birds is recommended. If 

community nest boxes are provided, there should be at least 9 square feet of nesting space 

for every 100 hens.

Laying hens must also be provided with perches—at least 6 inches of elevated perch space 

per hen is suggested. There must be enough perch and/or flat roost space for all hens to 

simultaneously rest off of the floor at night. Turkeys can be provided with elevated platforms 

and ramps in addition to or instead of perches.112

Poultry must be provided with dustbathing areas. Preferred substrates include sand, wood 

shavings and peat. On outdoor range areas, chickens usually create their own preferred 

dustbathing locations in loose, dry dirt. Dustbathing balances oil levels in the 

feathers,113,114,115 and helps keep the plumage in good condition.

Ducks should have access to water for bathing and head dunking in addition to water for 

drinking. Water related activity is part of the natural behavior of waterfowl. At a minimum, 

ducks should be able to dip their heads and splash their feathers with water. This behavior 

will help keep their nostrils, eyes and feathers clean.116,117 Troughs are often used to provide 

an open water source and these can be situated on grids or slats over a drainage channel to 

prevent adjacent litter from becoming wet. Nipple drinkers do not permit ducks to wet their 

eyes or feathers, and can lead to poor eye and plumage cleanliness.118 Open water sources 

should be cleaned daily.

Additional producer guidance on providing perches for laying hens in indoor housing

Perches are an important enrichment in indoor housing for laying hens. The foot of a hen is 

anatomically adapted to close around a perch,

119,120 and this is the natural resting position for 

chickens. Perch use maintains bone volume and bone strength,

121,122,123 and can serve as a 

refuge for subordinate hens to avoid aggressive interactions with more dominant hens.

124 

Research demonstrates that hens are highly motivated to perch at night.125,126,127 When 

given a choice, hens often prefer to roost on higher perches as opposed to those that are 

closer to the floor.

128,129 

Bumblefoot is a bulbous swelling of the footpad caused by a localized infection.130 Some hen 

breeds are more susceptible than others, and the condition is associated with poor hygiene 

and poor perch design.131,132 The use of plastic perches or the commonly used soft wooden 

perches measuring 25 mm (0.98 in) in width are thought to contribute to poor foot health, as 

manure and moisture are able to accumulate on the structure’s top where the birds’ feet 

rest.133 Incidence of bumblefoot can be reduced by providing hens with hardwood perches 

that are approximately 1.5 inches in diameter with a flattened top134,135 and by limiting 

walking exposure to mud and manure.136

Hens selected for egg production are prone to osteoporosis and subsequent bone 

fractures.

137,138,139 These often go undetected unless hens are palpated by an experienced 

veterinarian. The way perches are arranged inside the poultry house can have an effect on 

the incidence of bone fractures. Research suggests that the upper limit on a hen’s ability to 

jump from one perch to another is about three feet,140 and angles greater than approximately 

45o can be difficult to navigate.

141 At a minimum, hens need approximately 6 inches of perch 

LC 10 Animal Welfare-Poultry
space to take-off, and 6-9 inches to land.

142 Perches should be large enough for hens to 

maintain stable footing, about 1.5 inches in diameter.

143,144 These general requirements may 

differ depending on the size and previous experience of the hen, so adjustments may be 

necessary for individual flocks. Injuries are more likely to occur if perch design and layout 

require hens to jump beyond their natural capabilities.145

Providing perches at a young age can also help reduce the risk of floor eggs,146 as pullets 

must be skilled at flying up and down in order to access elevated nest boxes.147

Outdoor access and living conditions

Outdoor access must be provided to all poultry, with the following exceptions:

• Pullets younger than 12 weeks of age.

• Broiler chickens younger than 4 weeks of age.

• Outdoor temperatures below 50oF.

• Other inclement weather such as heavy snow, sleet, rain, wind or extreme heat that would 

endanger the health or welfare of the animals.

Pullets must be provided outdoor access by 12 

weeks of age, when weather permits. As a guide, 

doors for outdoor access should be at least 14 

inches high, spaced uniformly and provide direct 

access to the outdoors. Total door opening should 

be at least 6 feet/1000 birds.

148 Once layers are 

accustomed to going outdoors, a brief confinement 

period of no more than 5 weeks to allow for nest box 

training is permitted. Broiler chickens must be 

provided outdoor access by 4 weeks of age, 

provided that they are fully feathered and weather 

permits. 

Enclosed spaces that have a solid roof overhead (sometimes called “porches” or “winter 

gardens”) do not meet the definition of outdoor access and cannot be included in the space 

calculation of outdoor access. 

Additional producer guidance on outdoor access

Outdoor areas for poultry should be fully vegetated, where possible. Grasses, legumes, and 

other forage provide interest and enrichment to poultry, who consume not only greens, but 

also insects, grubs, and seeds. However, high traffic areas tend to become denuded of 

vegetation, so steps must be taken to keep outdoor areas in good condition. Rotate the use 

of range areas by taking flocks off of pasture to prevent the buildup of infectious organisms 

and allow the re-growth of vegetation. Fields can also be rotated between species with 

different parasite spectrums, such as cattle and poultry. Harvested crop fields also make 

good poultry runs.

Layout is important for attracting hens to use outdoor space. There should be plenty of exits 

from the hen house, and they should be easily accessible and large enough for several hens 

to pass through simultaneously. Since hens are prey animals, they are naturally wary of 

LC 11 Animal Welfare-Poultry
overhead predators, and will sometimes avoid open range if some sort of cover is not 

provided. Cover, either artificial or natural structures, should therefore be provided.149

Natural cover can take many forms, including tall plantings of vegetation, bushes, and 

trees,150 however, large swaths of thick undergrowth can actually attract ground predators if 

fences don’t exclude them. Maize plantings and low pollard willows (Salix), for example, 

have worked on organic farms to attract hens outdoors.151 In “tree-range” production, the 

outdoor area is planted with short trees, such as orchard varieties. Flocks with canopy cover 

from trees are more likely to have better plumage condition at the end of lay than those 

without canopy cover.152 

Artificial structures that provide shelter, shade, and 

security can also be constructed.153,154 Cover made 

from a wide variety of wood, plastic or recycled

materials, in designs both low to the ground and high 

enough to include perches, have been innovated by 

producers with success. Camouflage nets are 

another option.155 If artificial cover is portable, it can 

be moved to different range areas to encourage more 

even distribution of the flock, preventing buildup of 

contamination over highly frequented areas.

For more information see: Fanatico, A. 2006. Alternative poultry production systems and 

outdoor access. Available through the National Sustainable Agriculture Information Service 

at: www.attra.ncat.org

Space allowances

Poultry housing must be sufficiently spacious to allow all birds to move freely, stretch their 

wings and engage in natural behavior. Perching areas and nest boxes may not be used in 

the calculation of floor space. Slatted/grated floors may be considered floor space. Mobile 

poultry units require the same amount of indoor space per bird but allow the house to be 

moved so birds always have access to fresh vegetation. 

Livestock Species Indoor Space Outdoor Runs and 

Pens 

Chickens

Laying hens and 

breeders

1.5 sq ft / bird

 

2.0 sq ft / bird

 

Pullets 5 lbs / sq ft 5 lbs / sq ft

Broilers 5 lbs / sq ft 5 lbs / sq ft

Other poultry

Turkeys and 

Geese—breeding, 

7.5 lbs / sq ft

 

2 lbs / sq ft

 

LC 12 Animal Welfare-Poultry
laying, or meat birds 

(pounds)

Ducks-meat 5 lbs / sq ft 2 lbs / sq ft

Ducks-laying hen 2 lbs / sq ft 1 lbs / sq ft

Ducks—breeder 3.3 lbs / sq ft 1 lbs / sq ft

Humane handling of poultry

Poultry should be handled quietly and firmly, with care taken to avoid unnecessary distress 

and dislocated or broken bones during catching and loading for transport. Poultry catching 

should be scheduled to minimize the time to slaughter as well as climatic stress during 

catching, transport and holding. Birds should not be picked up by the neck or wings. 

Transport is a stressful experience,

156,157 as birds are subjected to noise, vibration, motion, 

overcrowding, feed and water deprivation, social disruption, and potential temperature 

extremes.158,159,160 Aim to reduce these stressors and comfort the birds wherever possible. 

Transportation units should provide space enough that all birds can lie down at the same time 

and none are on top of each other. Birds must be protected from heat and cold. Delivery of 

poultry for slaughter should be scheduled such that they are not deprived of water for longer 

than 12 hours. 

Birds must be fit for transport before being loaded for slaughter. Due to the stress involved, 

animals must be healthy enough to withstand the rigors of the journey. Birds exhibiting 

obvious signs of poor health, weakness or injury are not fit for transport. These birds should 

be euthanized using the most humane method available.

Inspectors should discuss procedures for poultry catching and loading with the producer and 

must observe poultry being caught and loaded for slaughter at the annual inspection and note 

percentage of birds with broken/dislocated legs/wings. 

Additional producer guidance on humane handling of poultry

Low-stress handling is as important for poultry as it is for livestock. Although commonly 

carried this way, research shows that birds react with a significant stress response when 

picked up and held upside-down by the legs, as this is a physiologically abnormal posture for 

chickens.161 Handling, crating and loading for transportation, have been identified by 

researchers as major sources of stress and trauma.162 Bruising and injuries are welldocumented, and these are not only welfare problems, but can also result in carcass 

downgrading and economic loss to producers.

163, 164,165,166,167 Ideally, all poultry should be 

handled individually, upright, and carried gently using two hands.

Catching and carrying turkeys can also cause bruises and injuries. Turkeys can be driven or 

herded into transport crates instead, which reduces stress levels.

168

LC 13 Animal Welfare-Poultry
Euthanasia and depopulation

Individual birds who are ill or injured, are suffering, and are unlikely to recover, should be 

euthanized without delay. All euthanized and depopulated birds must be confirmed dead 

before disposal. No live birds should be found on dead piles.

Permitted methods include:

• Hand held electrical or percussive stunning using an instrument designed for the specific 

size/age of the species, followed by neck cutting;

• Cervical dislocation by stretching the neck to sever the spinal cord and cause extensive 

damage to the major blood vessels.

• Barbiturate overdose administered by a licensed veterinarian (with special considerations 

noted below)

• Decapitation

• Carbon dioxide or a mixture of nitrogen and argon gases, delivered in an appropriate 

container at acceptable concentrations.

Acceptable gas mixtures include:

• a minimum of 2 minutes exposure to any mixture of argon, nitrogen or other inert gases with 

atmospheric air and carbon dioxide, provided that the carbon dioxide concentration does 

not exceed 30 percent by volume and the residual oxygen concentration does not exceed 2 

percent by volume; or

• a minimum of 2 minutes exposure to argon, nitrogen, other inert gases or any mixture of 

these gases in atmospheric air with a maximum of 2 percent residual oxygen by volume.

Methods that are not permitted include, but are not limited to: 

• Suffocation

• Blow to the head by blunt instrument

• Equipment that crushes the neck including killing pliers or burdizzo clamps

• Carbon monoxide

• Neck wringing (holding the head while swinging the body in a circular motion)

• Maceration in a wood chipper

Additional producer guidance on euthanasia and depopulation

The term euthanasia is derived from Greek words meaning “good death” and is applied to the 

killing of an animal with minimal pain and distress.169 Animals that are suffering must be 

euthanized in a timely manner, and should not be left for extensive periods, over a weekend, 

for example.

Barbiturate injection or inhalant anesthetics administered by a veterinarian are the ideal 

methods for a limited numbers of hens, as they most closely meet the goals of killing with 

minimal pain and distress. However, these methods have not been widely used on farm 

settings due to cost and convince issues associated with culling large numbers of birds. 

Producers should also be aware that drug residues associated with the use of barbiturate 

injections will prevent the use of carcasses for human consumption, and dead birds must be 

disposed of carefully, because residues could also be unwittingly consumed by other animals 

eating the carcass or could become an environmental pollutant. Dead poultry should be 

disposed of in a way that does not attract wildlife. 

LC 14 Animal Welfare-Poultry
Research demonstrates that inhalation of an inert gas (including argon and nitrogen) is 

probably painless, as they are colorless, odorless gases and birds do not demonstrate 

aversive reactions with initial exposure. In carefully controlled behavior experiments, turkeys 

and chickens are willing to enter a chamber filled with inert gas in order to access food.170,171 

Argon and nitrogen can be used to kill chickens on the farm. Containerized gas killing 

systems have been developed for culling large numbers of birds,172 and these can be built on 

either a large or small scale, depending on the needs of individual producers. Such a system 

is the most humane method for killing large numbers of chickens on the farm that researchers 

have identified to date.

The use of CO2 is problematic as there are both physiological and behavioral lines of 

scientific evidence suggesting that CO2 may be unpleasant and possibly very distressing to 

inhale, as it is an acidic gas, pungent at high concentrations.173,174 

Exhaust fumes from an idling car engine are an unacceptable source of carbon monoxide, 

due to problems with production of other gases, inadequate gas concentration, and gas

temperature. 

While purpose-build macerators are sometimes used to kill unwanted chicks at hatcheries, 

using a wood chipper to dispose of a spent laying-hen flock is never acceptable. 

It is extremely important to confirm that all animals are dead before disposal. When 

depopulation is performed on large flocks, depending on the methods used, it can be difficult 

to ensure that birds are actually dead and not simply lying still or unconscious. There is a 

very high potential for birds that are not dead, but are severely injured, to suffer greatly. Each 

bird must be methodically checked, and dead piles must be examined carefully for any sign 

of movement. A backup method of euthanasia must be in place to kill any birds that recover. 

Careful attention to this step in the euthanasia process is essential to ensuring a humane end 

for farmed poultry.

Slaughter of poultry

All slaughter facilities must be audited yearly. Organic certifiers can use documentation from 

other third-party animal welfare audits that have been performed and should do additional 

auditing as necessary. 

Slaughter establishments must also perform self-audits on a weekly basis. Self-audits 

ensure that animal welfare standards are being upheld, identify problems that may arise 

within the facility or with individual staff members, and identify specific farms that may be 

shipping problematic animals to the slaughter plant. These problems may be due to animals’ 

genetics or handling; slaughter facilities are encouraged to contact the producers of 

problematic animals so that these problems can be addressed in the future. 

In electrical water-bath stunning systems, birds must be shackled by both legs. Birds with 

broken or dislocated wings should be humanely killed before being shackled. 

Stunning

Poultry must be rendered unconscious by stunning, or killed before being bled by 

simultaneous severance of both carotid arteries or by decapitation. Bleeding without 

LC 15 Animal Welfare-Poultry
stunning requires a high level of operator competency to avoid causing pain and missing 

cutting of both carotid arteries. A very sharp blade or knife of sufficient length is needed so 

that the point of the knife remains outside the incision during the cut; the point of the knife 

should not be used to make the incision. The incision should not close over the knife during 

the throat cut. Decapitation may be achieved by manual or automatic means.

Decapitation must be performed using a sharp instrument which achieves the complete 

severance of the head from the body by cutting all the major vessels of the neck and the 

spinal cord with a sharp instrument. All mechanical and automatic instruments used in this 

method shall be sharp and inspected frequently for sharpness. The poultry slaughter 

establishment shall ensure that all instruments and equipment are maintained so that they 

function effectively. All birds (100%) should be dead before they enter the scald tank. 

For inspector assessment, 99% of the birds must be rendered insensible by the stunning 

method chosen. Arched neck and wings tucked in are visible signs of effective stunning. 

Additional producer/processor guidance on stunning for slaughter

Electric stunning: The disadvantage of electric stunning for poultry is that birds must be

shackled and hung upside-down before they enter the stunner. Care must be taken to avoid 

pre-stun electrical shocks. Amperage must be high enough that birds lose consciousness 

and are not merely paralyzed. The electric current shall be administered so as to produce 

effective surgical anesthesia or death with a minimum of excitement and discomfort. The 

current necessary to produce an effective stun changes depending the species and electrical 

frequency. These are outlined in the World Organization for Animal Health, Terrestrial 

Animal Health Guide, Chapter 7.5, Slaughter of animals (available at: 

www.oie.int/index.php?id=169&L=0&htmfile=chapitre_1.7.5.htm), and the minimum currents 

are as follows:

• Broiler chickens and spent laying hens, 100 milliamperes per bird

• Turkeys, 150 milliamperes per bird

• Ducks and geese, 130 milliamperes per bird

For high frequency settings of 200-400 Hz, the minimum current needed to stun chickens is 

150 milliamperes. For frequency settings of 400-1500 Hz, the minimum current is 200

milliamperes. For turkeys, frequency settings of 200-1500 Hz require a 400 milliampere 

currency setting. 

These are minimal settings, and higher current levels better ensure that more birds will be 

effectively rendered unconscious.

175 

Gas stunning: Acceptable gas mixtures include argon, nitrogen, and low initial levels of CO2

in one of the following combinations, as described by the World Organization for Animal 

Health:

• a minimum of 2 minutes exposure to 40 percent carbon dioxide, 30 percent oxygen and 30 

percent nitrogen, followed by a minimum of one minute exposure to 80 percent carbon 

dioxide in air; or

LC 16 Animal Welfare-Poultry
• a minimum of 2 minutes exposure to any mixture of argon, nitrogen or other inert gases with 

atmospheric air and carbon dioxide, provided that the carbon dioxide concentration does 

not exceed 30 percent by volume and the residual oxygen concentration does not exceed 2 

percent by volume; or

• a minimum of 2 minutes exposure to argon, nitrogen, other inert gases or any mixture of 

these gases in atmospheric air with a maximum of 2 percent residual oxygen by volume.

To avoid unnecessary stress and trauma due to handling, chickens should remain in their 

transport crates while being conveyed through the gas tunnels. Gas concentrations must be 

monitored for precision at all times. An alarm system is necessary to indicate malfunctions.

Bleeding

Once stunned, birds should be bled without delay to ensure that consciousness is not 

regained. Bleeding shall be accomplished by severing both carotid arteries or by 

decapitation. Sufficient bleeding time (at lest 30 seconds, 60 seconds for gas stunning, and 

approximately 2 to 3 minutes for electric stunning resulting in cardiac arrest) shall be allowed 

to prevent the unacceptable condition known as “red skins” or “cadavers” which may occur 

with insufficient bleeding. For inspector assessment, 99% must be effectively cut by hand or 

by the bleed machine. Remaining birds must be cut by a backup person.

The inspector will monitor condition of carcasses exiting the scald tank. Birds exiting the 

scald tank should not show signs that they entered it alive. “Red skins” with uncut throats 

indicate that they entered the scalding water alive, and those with cut throats could possibly 

have entered before becoming unconscious.

For poultry, the percentage of chickens with broken or dislocated wings should not exceed 

2%, with zero being the goal. No broken legs should be noted.

1 Dennis RL, Fahey AG, and Cheng HW. 2009. Infrared beak treatment method compared with 

conventional hot-blade trimming in laying hens. Poultry Science 88:38-43.

2 Garner JP, Falcone C, Wakenell P, Martin M and Mench JA. 2002. Reliability and validity of a 

modified gait scoring system and its use in assessing tibial dyschondroplasia in broilers. British 

Poultry Science 43:355-63.

3 Kestin SC, Knowles TG, Tinch AE, and Gregory. 1992. Prevalence of leg weakness in broiler 

chickens and its relationship with genotype. The Veterinary Record 131:190-4.

4 Mench J. 2004. Lameness. In: Weeks C and Butterworth A (ed.s), Measuring and Auditing Broiler 

Welfare (Walingford, U.K.: CABI Publishing, pp.3-17).

5 Knowles TG, Kestin SC, Haslam SM, Brown SN, Green LE, Butterworth A, Pope SJ, Pfeiffer D, and 

Nicol CJ. 2008. Leg Disorders in Broiler Chickens: Prevalence, Risk

Factors and Prevention. PLoS ONE 3(2):e1545. doi:10.1371/journal.pone.0001545.

6 Danbury TC, Weeks CA, Chambers JP, Waterman-Pearson AR, and Kestin SC. 2000. Self selection 

of the analgesic drug carprofen by lame broiler chickens. The Veterinary Record 146:307-11.

LC 17 Animal Welfare-Poultry
7 McGeown D, Danbury TC, Waterman-Pearson AE, and Kestin SC. 1999. Effect of carprofen on 

lameness in broiler chickens. Veterinary Record 144: 668-71.

8 Bessei W. 2006. Welfare of broilers: a review. World’s Poultry Science Journal 62:455-66.

9 Berg C. 2004. Pododermatitis and hock burn in broiler chickens. In: Weeks C and Butterworth A 

(ed.s), Measuring and Auditing Broiler Welfare (Walingford, U.K.: CABI Publishing, pp.37-49).

10 Jones TA and Dawkins MS. 2010. Environment and management factors affecting Pekin duck 

production and welfare on commercial farms in the UK. British Poultry Science 51(1):12-21.

11 Kamyab A. 1997. Studies on the etiology of enlarged sternal bursa and focal ulcerative dermatitis 

on market tom turkeys. Ph.D. Dissertation, University of Minnesota, pp. 1, 33-43, 50. 12 Cook ME. 2000. Skeletal deformities and their causes: introduction. Poultry Science 79:982-4.

13 Bessei W. 2006. Welfare of broilers: a review. World’s Poultry Science Journal 62:455-66.

14 Kestin SC, Su G, and Sorensen P. 1999. Different commercial broiler crosses have different 

susceptibilities to leg weakness. Poultry Science 78:1085-90.

15 Van Middelkoop K, van Harn J, Wiers WJ, and van Horne P. 2002. Slower growing broilers pose 

lower welfare risks. World Poultry 18(8):20-1.

16 Knowles TG, Kestin SC, Haslam SM, Brown SN, Green LE, Butterworth A, Pope SJ, Pfeiffer D, and 

Nicol CJ. 2008. Leg Disorders in Broiler Chickens: Prevalence, Risk

Factors and Prevention. PLoS ONE 3(2):e1545. doi:10.1371/journal.pone.0001545.

17 Knowles TG, Kestin SC, Haslam SM, Brown SN, Green LE, Butterworth A, Pope SJ, Pfeiffer D, and 

Nicol CJ. 2008. Leg Disorders in Broiler Chickens: Prevalence, Risk

Factors and Prevention. PLoS ONE 3(2):e1545. doi:10.1371/journal.pone.0001545.

18 Dawkins MS, Donnelly CA and Jones TA. 2004. Chicken welfare is influenced more by housing 

conditions than by stocking density. Nature 427:342-4.

19 Bessei W. 2006. Welfare of broilers: a review. World’s Poultry Science Journal 62:455-66.

20 Berg C. 2004. Pododermatitis and hock burn in broiler chickens. In: Weeks C and Butterworth A 

(ed.s), Measuring and Auditing Broiler Welfare (Walingford, U.K.: CABI Publishing, pp.37-49).

21 Bessei W. 2006. Welfare of broilers: a review. World’s Poultry Science Journal 62:455-66.

22 Berg C. 2004. Pododermatitis and hock burn in broiler chickens. In: Weeks C and Butterworth A 

(ed.s), Measuring and Auditing Broiler Welfare (Walingford, U.K.: CABI Publishing, pp.37-49).

23 Pagazaurtundua A and Warriss PD. 2006. Levels of foot pad dermatitis in broiler chickens reared in 

5 different systems. British Poultry Science 47(5):529-32.

24 Berg C. 2004. Pododermatitis and hock burn in broiler chickens. In: Weeks C and Butterworth A 

(ed.s), Measuring and Auditing Broiler Welfare (Walingford, U.K.: CABI Publishing, pp.37-49).

25 Jones TA and Dawkins MS. 2010. Environment and management factors affecting Pekin duck 

production and welfare on commercial farms in the UK. British Poultry Science 51(1):12-21.

26 Berg C. 2004. Pododermatitis and hock burn in broiler chickens. In: Weeks C and Butterworth A 

(ed.s), Measuring and Auditing Broiler Welfare (Walingford, U.K.: CABI Publishing, pp.37-49).

27 European Food Safety Authority, Animal Health and Animal Welfare. 2005. Scientific report on the 

welfare aspects of various systems for keeping laying hens. EFSA-Q-2003-92, p. 27. Annex to The 

EFSA Journal 197, 1-23. www.efsa.europa.eu/EFSA/Scientific_Opinion/lh_scirep_final1.pdf. 28 Scientific Panel on Animal Health and Welfare. 2005. Opinion of the Scientific Panel on Animal 

Health and Welfare on a request from the Commission related to the welfare aspects of various 

systems of keeping laying hens. The EFSA Journal 197:1-23. 

www.efsa.europa.eu/EFSA/Scientific_Opinion/lh_opinion1.pdf. 29 Hane M, Huber-Eicher B, and Frohlich E. 2000. Survey of laying hen husbandry in Switzerland. 

World’s Poultry Science Journal 56:21-31.

30 Fanatico A. 2006. Parasite Management for Natural and Organic Poultry: Coccidiosis. National 

Sustainable Agriculture Information Service. http://attra.ncat.org/attra-pub/PDF/coccidiosis.pdf. 31 Hy-Line®. 2007-2008. W-36 commercial management guide. www.hy-line.com/userdocs/library/W36_Eng_indd.pdf. 32 McDougald LR. 2003. Internal parasites. In: Saif YM, Barnes HJ, Gilsson JR, Fadly AM, McDougald 

LR, and Swayne DE (eds.), Diseases of Poultry, 11th Edition (Ames, IA: Iowa State Press, p. 943).

LC 18 Animal Welfare-Poultry
33 Bassler A, Ciszuk P, Sjelin K: Management of laying hens in mobile houses – a review of 

experiences. 1999. In: Hermansen JE, Lund V, and Thuen E (eds.), Proceedings NJF-seminar No 

303, Ecological Animal Husbandry in the Nordic Countries (Horsens, Denmark: Danish Research 

Center for Organic Farming, pp. 45-50). www.foejo.dk/publikation/rapport/dar_2.pdf. 34 Fanatico A. 2006. Alternative poultry production systems and outdoor access. National Sustainable 

Agriculture Information Service. http://attra.ncat.org/attra-pub/PDF/poultryoverview.pdf. 35 Thear K. 2002. Free-Range Poultry Production (Suffolk, U.K.: Whittet Books Ltd., pp. 70-2).

36 Fanatico A. 2006. Alternative poultry production systems and outdoor access. National Sustainable 

Agriculture Information Service. www.attra.ncat.org/attra-pub/PDF/poultryoverview.pdf. 37 Newberry RC. 2003. Cannibalism. In: Perry GC (ed.), Welfare of the Laying Hen, Poultry Science 

Symposium Series, 27 (Wallingford, U.K.: CABI Publishing, pp. 239-58).

38 Rodenburg TB, Komen H, Ellen ED, Uitdehaag KA, van Arendonk JAM. 2008. Selection method 

and early-life history affect behavioural development, feather pecking and cannibalism in laying hens: 

A review. Applied Animal Behaviour Science 110:217-28.

39 Hartini S, Choct M, Hinch G, Kocher A, and Nolan JV. 2002. Effects of light intensity during

rearing and beak trimming and dietary fiber sources on mortality, egg production, and performance of 

ISA brown laying hens. Journal of Applied Poultry Research 11:104-10.

40 Lambton SL, Knowles TG, Yorke C, and Nicol CJ. 2010. The risk factors affecting the development 

of gentle and severe feather pecking in loose housed laying hens. Applied Animal Behaviour Science 

123(1):32-42.

41 Cheng H. 2006. Morphopathological changes and pain in beak trimmed laying hens. World’s 

Poultry Science Journal 62(1):41-52.

42 Lunam CA. 2005. The anatomy and innervation of the chicken beak: effects of trimming and retrimming. In: Glatz PC (ed.), Poultry Welfare Issues: Beak Trimming (Nottingham, U.K.: Nottingham 

University Press, pp.51-68).

43 Hughes BO and Duncan IJH. 1972. The influence of strain and environmental factors upon feather 

pecking and cannibalism in fowls. British Poultry Science 13:525-47.

44 Ambrosen T and Petersen VE. 1997. The influence of protein level in the diet on cannibalism and 

quality of plumage of layers. Poultry Science 76:559-63.

45 Van Krimpen MM, Kwakkel RP, Reuvekamp BFJ, Van der Peet-Schwering CMC, Den Hartog LA, 

and Verstegen MWA. 2005. Impact of feeding management on feather pecking in laying hens. World’s 

Poultry Science Journal 61:663-86.

46 Rodenburg TB, Komen H, Ellen ED, Uitdehaag KA, van Arendonk JAM. 2008. Selection method 

and early-life history affect behavioural development, feather pecking and cannibalism in laying hens: 

A review. Applied Animal Behaviour Science 110:217-28.

47 Dixon LM, Mason GJ, and Duncan IJH. 2007. What’s in a peck? A comparison of the motor 

patterns involved in feather pecking, dustbathing and foraging. In: Galindo F and Alvarez L (eds.), 

Proceedings of the 41st International Congress of the ISAE (Merida, Mexico: International Society for 

Applied Ethology, p.47).

48 Huber-Eicher B and Wechsler B. 1997. Feather pecking in domestic chicks: its relation to 

dustbathing and foraging. Animal Behaviour 54:757-68.

49 Blokhuis HJ. 1986. Feather-pecking in poultry: its relation with ground-pecking. Applied Animal 

Behaviour Science:16:63-7.

50 Savory CJ, Wood-Gush DGM, and Duncan IJH. 1978. Feeding behaviour in a population of 

domestic fowls in the wild. Applied Animal Ethology 4:13-27.

51 Dawkins MS. 1989. Time budgets in Red Junglefowl as a baseline for the assessment of welfare in 

domestic fowl. Applied Animal Behaviour Science 24:77-80.

52 Dawkins MS. 1989. Time budgets in Red Junglefowl as a baseline for the assessment of welfare in 

domestic fowl. Applied Animal Behaviour Science 24:77-80.

53 Duncan IJH and Hughes BO. 1972. Free and operant feeding in domestic fowls. Animal Behaviour 

20:775-7.

LC 19 Animal Welfare-Poultry
54 Newberry RC. 2003. Cannibalism. In: Perry GC (ed.), Welfare of the Laying Hen, Poultry Science 

Symposium Series, 27 (Wallingford, U.K.: CABI Publishing, pp. 239-58).

55 Rogers L. 1995. The Development of Brain and Behaviour in the Chicken (Wallingford, U.K.: CAB 

International, pp. 95-110).

56 Rogers L. 1995. The Development of Brain and Behaviour in the Chicken (Wallingford, U.K.: CAB 

International, pp. 95-110).

57 Huber-Eicher B and Sebö F. 2001. Reducing feather pecking when raising laying hen chicks in

aviary systems. Applied Animal Behaviour Science 73:59-68.

58 Johnsen PF, Vestergaard KS, Nørgaard-Nielsen G.1998. Influence of early rearing conditions of the 

development of feather pecking and cannibalism in domestic fowl. Applied Animal Behaviour Science 

60:25-41.

59 Huber-Eicher B and Sebö F. 2001. Reducing feather pecking when raising laying hen chicks in 

aviary systems. Applied Animal Behaviour Science 73:59-68.

60 Aerni V, Brinkhof MWG, Wechsler B, Oester H, and Fröhlich E. 2005. Productivity and mortality of 

laying hens in aviaries: a systematic review. World’s Poultry Science Journal 61(1):130-42.

61 Johnsen PF, Vestergaard KS, and Nørgaard-Nielsen G. 1998. Influence of early rearing conditions 

on the development of feather pecking and cannibalism in domestic fowl. Applied Animal Behaviour 

Science 60:25-41.

62 Nicol CJ, Lindberg AC, Phillips AJ, Pope SJ, Wilkins LJ, and Green LE. 2001. Influence of prior 

exposure to wood shavings on feather pecking, dustbathing and foraging in adult laying hens. Applied 

Animal Behaviour Science 73:141-55.

63 Huber-Eicher B and Sebö F. 2001. Reducing feather pecking when raising laying hen chicks in 

aviary systems. Applied Animal Behaviour Science 73:59-68.

64 Green LE, Lewis K, Kimpton A, and Nicol CJ. 2000. Cross-sectional study of the prevalence of 

feather pecking in laying hens in alternative systems and its associations with management and 

disease. Veterinary Record 147:233-8.

65 Knierim U, Staack M, Gruber B, Keppler C, Zaludik K, and Niebuhr K. 2008. Risk factors for feather 

pecking in organic laying hens –starting points for prevention in the housing environment. 16th IFOAM 

Organic World Congress, Modena, Italy, June 16-20.

66 Knierim U, Staack M, Gruber B, Keppler C, Zaludik K, and Niebuhr K. 2008. Risk factors for feather 

pecking in organic laying hens –starting points for prevention in the housing environment. 16th IFOAM 

Organic World Congress, Modena, Italy, June 16-20.

67 Knierim U, Staack M, Gruber B, Keppler C, Zaludik K, and Niebuhr K. 2008. Risk factors for feather 

pecking in organic laying hens –starting points for prevention in the housing environment. 16th IFOAM 

Organic World Congress, Modena, Italy, June 16-20.

68 Gunnarsson S, Keeling LJ, Svedberg J. 1999. Effect of rearing factors on the prevalence of floor 

eggs, cloacal cannibalism and feather pecking in commercial flocks of loose housed laying hens. 

British Poultry Science 40:12-8.

69 Newberry RC. 2003. Cannibalism. In: Perry GC (ed.), Welfare of the Laying Hen, Poultry Science 

Symposium Series, 27 (Wallingford, U.K.: CABI Publishing, pp. 239-58).

70 Huber-Eicher and Audigé. 1999. Analysis of risk factors for the occurrence of feather pecking in 

laying hen growers. British Poultry Science 40:599-604.

71 Gunnarsson S, Yngvesson J, Keeling LJ, and Forkman B. 2000. Rearing without early access to 

perches impairs the spatial skills of laying hens. Applied Animal Behaviour Science 67:217-28.

72 Gunnarsson S, Keeling LJ, Svedberg J. 1999. Effect of rearing factors on the prevalence of floor 

eggs, cloacal cannibalism and feather pecking in commercial flocks of loose housed laying hens. 

British Poultry Science 40:12-8.

73 Huber-Eicher and Audigé. 1999. Analysis of risk factors for the occurrence of feather pecking in 

laying hen growers. British Poultry Science 40:599-604.

74 Wechsler B and Huber-Eicher B. 1998. The effect of foraging material and perch height on

feather pecking and feather damage in laying hens. Applied Animal Behaviour Science 58:131-41.

LC 20 Animal Welfare-Poultry
75 Bright A. 2009. Time course of plumage damage in commercial layers. Veterinary Record 164:334-

5.

76 Newberry RC. 2003. Cannibalism. In: Perry GC (ed.), Welfare of the Laying Hen, Poultry Science 

Symposium Series, 27 (Wallingford, U.K.: CABI Publishing, pp. 239-58). 77 Pötzsch CJ, Lewis K, Nicol CJ, and Green LE. 2001. A cross-sectional study of the prevalence of 

vent pecking in laying hens in alternative systems and its associations with feather pecking, 

management and disease. Applied Animal Behaviour Science 74:259-72.

78 Aerni V, El-Lethey H And Wechsler B. 2000. Effect of foraging material and food form on feather 

pecking in laying hens. British Poultry Science 41:16-21.

79 Lambton SL, Knowles TG, Yorke C, and Nicol CJ. 2010. The risk factors affecting the development 

of gentle and severe feather pecking in loose housed laying hens. Applied Animal Behaviour Science 

123(1):32-42.

80 Newberry RC. 2003. Cannibalism. In: Perry GC (ed.), Welfare of the Laying Hen, Poultry Science 

Symposium Series, 27 (Wallingford, U.K.: CABI Publishing, pp. 239-58).

81 Hartini S, Choct M, Hinch G, Kocher A, and Nolan JV. 2002. Effects of light intensity during rearing 

and beak trimming and dietary fiber sources on mortality, egg production, and performance of ISA 

brown laying hens. Journal of Applied Poultry Research 11:104-10.

82 Choct M and Hartini S. 2005. Interaction between nutrition and cannibalism in laying hens. In: Glatz 

PC (ed.), Poultry Welfare Issues: Beak Trimming (Nottingham, U.K.: Nottingham University Press, 

pp.111-5).

83 Steenfeldt S, Kjaer JB, and Engberg RM. 2007. Effect of feeding silages or carrots as supplements 

to laying hens on production performance, nutrient digestibility, gut structure, gut microflora and 

feather pecking behaviour. British Poultry Science 48(4):454-68.

84 Nørgaard-Nielsen G, Vestergaard K, and Simonsen HB. 1993. Effects of rearing experience and 

stimulus enrichment on feather damage in laying hens. Applied Animal Behaviour Science 38:345-52.

85 Martrenchar A, Huonnic D, and Cotte JP. 2003. Influence of environmental enrichment on injurious 

pecking and perching behaviour in young turkeys. British Poultry Science 42:161-70.

86 Dixon LM, Duncan IJH, and Mason GJ. 2010. The effects of four types of enrichment on featherpecking behaviour in laying hens housed in barren environments. Animal Welfare 19:429-35.

87 Nicol CJ, Pötzsch C, Lewis K, and Green LE. 2003. Matched concurrent case-control study of risk 

factors for feather pecking in hens on free-range commercial farms in the UK. British Poultry Science 

44:515-23.

88 Bestman MWP. 2001. The role of management and housing in the prevention of feather pecking in 

laying hens. In: Hovi M and Bouilhol M (eds.), Human-Animal Relationship: Stockmanship and 

Housing in Organic Livestock Systems. Proceedings of the Third NAHWOA Workshop (ClermontFerrand, France: Network for Animal Health and Welfare in Organic Agriculture, University of 

Reading, pp.77-86). www.veeru.rdg.ac.uk/organic/ProceedingsFINAL.pdf. 89 Green LE, Lewis K, Kimpton A, and Nicol CJ. 2000. Cross-sectional study of the prevalence of 

feather pecking in laying hens in alternative systems and its associations with management and 

disease. Veterinary Record 147:233-8.

90 Lambton SL, Knowles TG, Yorke C, and Nicol CJ. 2010. The risk factors affecting the development 

of gentle and severe feather pecking in loose housed laying hens. Applied Animal Behaviour Science 

123(1):32-42.

91 Nicol CJ, Pötzsch C, Lewis K and Green LE. 2003. Matched concurrent case-control study of risk 

factors for feather pecking in hens on free-range commercial farms in the UK. British Poultry Science 

44(4):515-23.

92 Bestman MWP and Wagenaar JP. 2003. Farm level factors associated with feather pecking in 

organic laying hens. Livestock Production Science 80:133-40.

93 Mahboub HDH, Müller J, and von Borell E. 2004. Outdoor use, tonic immobility, 

heterophil/lymphocyte ratio and feather condition in free-range laying hens of different genotype. 

British Poultry Science 45(6):738-44.

LC 21 Animal Welfare-Poultry
94 Green LE, Lewis K, Kimpton A, and Nicol CJ. 2000. Cross-sectional study of the prevalence of 

feather pecking in laying hens in alternative systems and its associations with management and 

disease. Veterinary Record 147:233-8. 

95 Elwinger K., Tufvesson M., Lagerkvist G, and Tauson R. 2008. Feeding layers of different 

genotypes in organic feed environments. British Poultry Science 49(6):654-65.

96 Nicol CJ, Pötzsch C, Lewis K, and Green LE. 2003. Matched concurrent case-control study of risk 

factors for feather pecking in hens on free-range commercial farms in the UK. British Poultry Science 

44:515-23.

97 Nicol CJ, Pötzsch C, Lewis K, and Green LE. 2003. Matched concurrent case-control study of risk 

factors for feather pecking in hens on free-range commercial farms in the UK. British Poultry Science 

44:515-23.

98 Green LE, Lewis K, Kimpton A, and Nicol CJ. 2000. Cross-sectional study of the prevalence of 

feather pecking in laying hens in alternative systems and its associations with management and 

disease. Veterinary Record 147:233-8.

99 Pötzsch CJ, Lewis K, Nicol CJ, and Green LE. 2001. A cross-sectional study of the prevalence of 

vent pecking in laying hens in alternative systems and its associations with feather pecking, 

management and disease. Applied Animal Behaviour Science 74:259-72.

100 Pötzsch CJ, Lewis K, Nicol CJ, and Green LE. 2001. A cross-sectional study of the prevalence of 

vent pecking in laying hens in alternative systems and its associations with feather pecking, 

management and disease. Applied Animal Behaviour Science 74:259-72.

101 Green LE, Lewis K, Kimpton A, and Nicol CJ. 2000. Cross-sectional study of the prevalence of 

feather pecking in laying hens in alternative systems and its associations with management and 

disease. Veterinary Record 147:233-8.

102 Pötzsch CJ, Lewis K, Nicol CJ, and Green LE. 2001. A cross-sectional study of the prevalence of 

vent pecking in laying hens in alternative systems and its associations with feather pecking, 

management and disease. Applied Animal Behaviour Science 74:259-72.

103 Knierim U, Staack M, Gruber B, Keppler C, Zaludik K, and Niebuhr K. 2008. Risk factors for feather 

pecking in organic laying hens –starting points for prevention in the housing environment. 16th IFOAM 

Organic World Congress, Modena, Italy, June 16-20.

104 Green LE, Lewis K, Kimpton A, and Nicol CJ. 2000. Cross-sectional study of the prevalence of 

feather pecking in laying hens in alternative systems and its associations with management and 

disease. Veterinary Record 147:233-8.

105 Bestman MWP and Wagenaar JP. 2003. Farm level factors associated with feather pecking in 

organic laying hens. Livestock Production Science 80:133-40.

106 Newberry RC. 2003. Cannibalism. In: Perry GC (ed.), Welfare of the Laying Hen, Poultry Science 

Symposium Series, 27 (Wallingford, U.K.: CABI Publishing, pp. 239-58).

107 Brunberg E, Jensen P, Isaksson A, and Keeling L. 2011. Feather pecking behavior in laying hens: 

Hypothalamic gene expression in birds performing and receiving pecks. Poultry Science 90:1145-52.

108 Ellen ED, Visscher J, van Arendonk JAM, and Bijma P. 2008. Survival of laying hens: genetic 

parameters for direct and associative effects in three purebred layer lines. Poultry Science 87:233-9.

109 Rodenburg TB, Uitdehaag KA, Ellen ED, and Komen J. 2009. The effects of selection on low 

mortality and brooding by a mother hen on open-field response, feather pecking and cannibalism in 

laying hens. Animal Welfare 18: 427-32.

110 Hocking PM, Channing CE, Robertson GW, Edmond A, and Jones RB. 2004. Between breed 

genetic variation for welfare-related behavioural traits in domestic fowl. Applied Animal Behaviour 

Science 89:85-105.

111 Rodenburg TB, Komen H, Ellen ED, Uitdehaag KA, van Arendonk JAM. 2008. Selection method 

and early-life history affect behavioural development, feather pecking and cannibalism in laying hens: 

A review. Applied Animal Behaviour Science 110:217-28.

112 Berk J and Cottin E. 2007. Effect of stocking densities and elevated platforms on behaviour, 

walking ability and leg posture of tom turkeys. In: Galindo F and Alvarez L (ed.s), Proceeding of the 

41st International Congress of the ISAE, Merida, Mexico, July 30th-August 3rd. 

LC 22 Animal Welfare-Poultry
113 Van Liere DW and Bokma S. 1987. Short-term feather maintenance as a function of dust-bathing 

in laying hens. Applied Animal Behaviour Science 18(2):197-204.

114 Olsson IAS and Keeling LJ. 2005. Why in earth? Dustbathing behaviour in jungle and domestic 

fowl reviewed from a Tinbergian and animal welfare perspective. Applied Animal Behaviour Science 

93(3-4):259-82.

115 Shields SJ. 2004. Dustbathing by broiler chickens: characteristics, substrate preference, and 

implications for welfare. Ph.D. Dissertation, University of California, Davis, pp.10-2.

116 Jones T, Waitt CD, and Stamp Dawkins M. 2009. Water off a duck’s back: Showers and troughs 

match ponds for improving duck welfare. Applied Animal Behaviour Science 116(1):52-7.

117 O’Driscoll KKM and Broom DM. 2011. Does access to open water affect the health of Pekin ducks 

(Anas platyrhynchos)? Poultry Science 90:299-307.

118 Jones TA and Dawkins MS. 2010. Environment and management factors affecting Pekin duck 

production and welfare on commercial farms in the UK. British Poultry Science 51(1):12-21.

119 Baxter M. 1994. The welfare problems of laying hens in battery cages. The Veterinary Record 

134(24):614-9.

120 Blokhuis HJ. 1984. Rest in poultry. Applied Animal Behaviour Science 12(3):289-303, citing: 

Ellenberger W and Baum H. 1943. Handbuch der vergleichenden Anatomie der Haustiere (Berlin, 

Germany: Springer Verlag, p. 1155).

121 Wilson S, Hughes BO, Appleby MC, and Smith SF. 1993. Effects of perches on trabecular bone 

volume in laying hens. Research in Veterinary Science 54(2):207-11.

122 Hughes BO, Wilson S, Appleby MC, and Smith SF. 1993. Comparison of bone volume and 

strength as measures of skeletal integrity in caged laying hens with access to perches. Research in 

Veterinary Science 54(2):202-6.

123 Duncan ET, Appleby MC, and Hughes BO. 1992. Effect of perches in laying cages on welfare and 

production of hens. British Poultry Science 33(1):25-35.

124 Appleby MC and Hughes BO. 1991. Welfare of laying hens in cages and alternative systems: 

environmental, physical and behavioural aspects. World’s Poultry Science Journal 47(2):109-28.

125 Baxter M. 1994. The welfare problems of laying hens in battery cages. The Veterinary Record 

134(24):614-9.

126 Olsson IAS and Keeling LJ. 2000. Night-time roosting in laying hens and the effect of thwarting 

access to perches. Applied Animal Behaviour Science 68(3):243-56.

127 Olsson IAS and Keeling LJ. 2002. The push-door for measuring motivation in hens: laying hens are 

motivated to perch at night. Animal Welfare 11(1):11-9.

128 Newberry RC, Estevez I, and Keeling L. 2001. Group size and perching behaviour in young 

domestic fowl. Applied Animal Behaviour Science 73:117-29.

129 Schrader L and Müller B. 2009. Night-time roosting in the domestic fowl: The height matters. 

Applied Animal Behaviour Science 121:179-83.

130 European Food Safety Authority, Animal Health and Animal Welfare. 2005. Scientific report on the 

welfare aspects of various systems for keeping laying hens. EFSA-Q-2003-92, p. 34. Annex to The 

EFSA Journal 197, 1-23. www.efsa.europa.eu/EFSA/Scientific_Opinion/lh_scirep_final1.pdf. 131 Scientific Panel on Animal Health and Welfare. 2005. Opinion of the Scientific Panel on Animal 

Health and Welfare on a request from the Commission related to the welfare aspects of various 

systems of keeping laying hens. The EFSA Journal 197:1-23. 

www.efsa.europa.eu/EFSA/Scientific_Opinion/lh_opinion1.pdf. 132 Tauson R and Abrahamsson P. 1996. Foot and keel bone disorders in laying hens: effects of 

artificial perch material and hybrid. Acta Agriculturae Scandinavica Section A, Animal Science 46:239-

46.

133 European Food Safety Authority, Animal Health and Animal Welfare. 2005. Scientific report on the 

welfare aspects of various systems for keeping laying hens. EFSA-Q-2003-92, p. 35. Annex to The 

EFSA Journal 197, 1-23. www.efsa.europa.eu/EFSA/Scientific_Opinion/lh_scirep_final1.pdf. 

LC 23 Animal Welfare-Poultry
134 Tauson R and Abrahamsson P. 1996. Foot and keel bone disorders in laying hens: effects of 

artificial perch material and hybrid. Acta Agriculturae Scandinavica Section A, Animal Science 46:239-

46.

135 European Food Safety Authority, Animal Health and Animal Welfare. 2005. Scientific report on the 

welfare aspects of various systems for keeping laying hens. EFSA-Q-2003-92, p. 35. Annex to The 

EFSA Journal 197, 1-23. www.efsa.europa.eu/EFSA/Scientific_Opinion/lh_scirep_final1.pdf. 136 LayWel. 2006. Welfare implications of changes in production systems for laying hens. 

www.laywel.eu/web/pdf/deliverable%2071%20welfare%20assessment.pdf. 137 Gregory NG and Wilkins LJ. 1991. Broken bones in hens. The Veterinary Record 129(25-26):559.

138 Nicol CJ, Brown SN, Glen E, et al. 2006. Effects of stocking density, flock size and management 

on the welfare of laying hens in single-tier aviaries. British Poultry Science 47(2):135-46.

139 Wilkins LJ, Brown SN, Zimmerman PH, Leeb C, and Nicol CJ. 2004. Investigation of palpation as a 

method for determining the prevalence of keel and furculum damage in laying hens. The Veterinary 

Record 155(18):547-9.

140 Scott GB and Parker CAL. 1994. The ability of laying hens to negotiate between horizontal 

perches. Applied Animal Behaviour Science 42:121-7.

141 Scott GB, Lambe,NR, and Hitchcock D. 1997. Ability of laying hens to negotiate horizontal perches 

at different heights, separated by different angles. British Poultry Science 38:48-54.

142 Moinard C, Rutherford KMD, Haskell MJ, McCorquodale C, Jones RB, and Green PR. 2005. 

Effects of obstructed take-off and landing perches on the flight accuracy of laying hens. Applied 

Animal Behaviour Science 93:81-95.

143 Struelens E, Tuyttens FAM, Ampe B., O ̈Dberg F, Sonck B, and Duchateau L. 2009. Perch width 

preferences of laying hens. British Poultry Science 50(4):418-23.

144 Pickel T, Scholz B, and Schrader L. 2010. Perch material and diameter affects particular perching 

behaviours in laying hens. Applied Animal Behaviour Science 127:37-42.

145 Scott GB and Parker CAL. 1994. The ability of laying hens to negotiate between horizontal 

perches. Applied Animal Behaviour Science 42:121-7.

146 Gunnarsson S, Keeling LJ, Svedberg J. 1999. Effect of rearing factors on the prevalence of floor 

eggs, cloacal cannibalism and feather pecking in commercial flocks of loose housed laying hens. 

British Poultry Science 40:12-8.

147 Colson S, Arnould C, and Michel V. 2008. Influence of rearing conditions of pullets on space use 

and performance of hens placed in aviaries at the beginning of the laying period. Applied Animal 

Behaviour Science 111:286-300.

148 Council Directive 1999/74/EC of 19 July 1999 laying down minimum standards for the protection of 

laying hens, chapter 1, article 4.3.b.1. Official Journal of the European Communities. 

http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:1999:203:0053:0057:EN:PDF

149 Hegelund L, Sørensen JT, Kjær JB, and Kristensen IS. 2005. Use of the range area in organic egg 

production systems: effect of climatic factors, flock size, age and artificial cover. British Poultry 

Science 46(1):1-8.

150 Bestman MWP. 2001. The role of management and housing in the prevention of feather pecking in 

laying hens. In: Hovi M and Bouilhol M (eds.), Human-Animal Relationship: Stockmanship and 

Housing in Organic Livestock Systems. Proceedings of the Third NAHWOA Workshop (ClermontFerrand, France: Network for Animal Health and Welfare in Organic Agriculture, University of 

Reading, pp.77-86). www.veeru.rdg.ac.uk/organic/ProceedingsFINAL.pdf. 151 Bestman MWP and Wagenaar JP. 2003. Farm level factors associated with feather pecking in 

organic laying hens. Livestock Production Science 80:133-40.

152 Bright A, Brass D, Clachan J, Drake KA and Joret AD. 2011. Canopy cover is correlated with 

reduced injurious feather pecking in commercial flocks of free-range laying hens. Animal Welfare 

20:329-38.

153 Zeltner E and Hirt H. 2008. Factors involved in the improvement of the use of hen runs. Applied 

Animal Behaviour Science 114:395-408.

154 Thear K. 2002. Free-Range Poultry (Suffolk, U.K.: Whittet Books Ltd., pp. 72-3).

LC 24 Animal Welfare-Poultry
155 Bestman MWP and Wagenaar JP. 2003. Farm level factors associated with feather pecking in 

organic laying hens. Livestock Production Science 80:133-40.

156 Mitchell M. 1992. Indicators of physiological stress in broiler chickens during road transportation. 

Animal Welfare 1:91-103.

157 Freeman BM, Kettlewell PJ, Manning ACC, and Berry PS. 1984. The stress of transportation for 

broilers. The Veterinary Record 114:286-7.

158 Mench J. 1992. The welfare of poultry in modern production systems. Poultry Science Reviews 

4:107-28.

159 Weeks C. 2007. Poultry handling and transport. In: Grandin T (ed.), Livestock Handling and 

Transport, 3rd Edition (Wallingford, U.K.: CAB International, pp. 295-311).

160 Duncan IJH. 1989. The assessment of welfare during the handling and transport of broilers. In: 

Faure JM and Mills AD (eds.), Proceedings of the Third European Symposium on Poultry Welfare

(Tours, France: French Branch of the World Poultry Science Association, pp. 79-91).

161 Kannan G, Heath JL, Wabeck CJ, and Mench JA. 1997. Shackling of broilers: effects on stress 

responses and breast meat quality. British Poultry Science 38(4):323-32.

162 Kettlewell PJ and Mitchell MA. 1994. Catching, handling and loading of poultry for road 

transportation. World’s Poultry Science Journal 50:54-6.

163 Kettlewell PJ and Turner MJB. 1985. A review of broiler chicken catching and transport systems. 

Journal of Agricultural Engineering Research 31:93-114.

164 McGuire AR. 2003. Improving carcass quality. Poultry 10(1):25-6.

165 Farsaie A, Carr LE, and Wabeck CJ. 1983. Mechanical harvest of broilers. Transactions of the 

American Society of Agricultural Engineers 26:1650-3.

166 Nijdam E, Zailan ARM, van Eck JHH, Decuypere E, and Stegeman JA. 2006. Pathological 

features in dead on arrival broilers with special reference to heart disorders. Poultry Science 85:1303-

8.

167 Gregory NG and Austin SD. 1992. Causes of trauma in broilers arriving dead at poultry 

processing plants. Veterinary Record 131:501-3.

168 Prescott NB, Berry PS, Haslam S, and Tinker DB. 2000. Catching and crating turkeys: effects on 

carcass damage, heart rate, and other welfare parameters. Journal of Applied Poultry Research 

9:424-32.

169 American Veterinary Medical Association. 2007. AVMA Guidelines on Euthanasia. 

www.avma.org/issues/animal_welfare/euthanasia.pdf

170 Webster AB and Fletcher DL. 2004. Assessment of the aversion of hens to different gas 

atmospheres using an approach-avoidance test. Applied Animal Behaviour Science 88(3-4):275-87.

171 Raj ABM. 1996. Aversive reactions of turkeys to argon, carbon dioxide and a mixture of carbon 

dioxide and argon. The Veterinary Record 138(24):592-3.

172 Raj M, O'callaghan M, Thompson K, et al. 2008. Large scale killing of poultry species on

farm during outbreaks of diseases: evaluation and development of a humane containerised gas killing 

system. World’s Poultry Science Journal 64:227-44.

173 Raj ABM. 2004. Stunning and slaughter of poultry. In: Mead GC (ed.), Poultry Meat Processing 

and Quality (Cambridge, U.K.: Woodhead Publishing Ltd.).

174 Raj M. 1998. Welfare during stunning and slaughter of poultry. Poultry Science 77(12):1815-9.

175 Hindle VA, Lambooij E, Reimert HGM, Workel LD, and Gerritzen MA. 2010. Animal welfare 

concerns during the use of the water bath for stunning broilers, hens, and ducks. Poultry Science 

89:401-12.

Committee vote:

Motion: Wendy Second: Colehour

Yes: 8 No: 0 Absent: 0 Abstain: 0 Recuse: 0 

 

LC 25 Animal Welfare-Poultry
LC 26 Animal Welfare-Poultry