Terrestrial Animal Health Code
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Terrestrial Animal Health Code |
Animal welfare and broiler chicken production systems
Definitions
For the purpose of this chapter:
Broiler: means a bird of the species Gallusgallus kept for commercial meat production. Poultry kept in village or backyard flocks are not included.
Harvesting: means the catching and loading of birds on farm for transportation to the slaughterhouse/abattoir.
Scope
This chapter covers the production period from arrival of day-old birds on the farm to harvesting the broilers in commercial production systems. Such systems involve confinement of the birds, the application of biosecurity measures, and trade in the products of those birds, regardless of scale of production. These recommendations cover broilers kept in cages, on slatted floors, litter or dirt and indoors or outdoors.
Broiler production systems include:
Completely housed system
Broilers are completely confined in a poultry house, with or without environmental control.
Partially housed system
Broilers are kept in a poultry house with access to a restricted outdoor area.
Completely outdoors system
Broilers are not confined inside a poultry house
at any time during the production period but are confined in a designated
outdoor area.
This chapter should be read in conjunction with Chapters 7.2., 7.3. and 7.4. on the welfare of broilers during transport to the slaughterhouse/abattoir.
Criteria or measurables for the welfare
of broilers
The welfare of broilers should be assessed using outcome-based measurables. Consideration should also be given to the resources provided and the design of the system. The following outcome-based measurables, specifically animal-based measurables, can be useful indicators of animal welfare. The use of these indicators and the appropriate thresholds should be adapted to the different situations where broilers are managed, also taking into account the strain of bird concerned.
Some criteria can be measured in the farm setting, such as gait, mortality and morbidity rates, while others are best measured at the slaughterhouse/abattoir. For example, at slaughterflocks can be assessed for presence of bruising, broken limbs and other injuries. The age of these lesions can help to determine the source. Back scratching and contact dermatitis and breast blisters are also easily observed at the slaughterhouse/abattoir. Other conditions such as ascites, leg deformities, dehydration and disease conditions can also be assessed at slaughter. It is recommended that values for welfare measurables be determined with reference to appropriate national, sectoral or perhaps regional norms for commercial broiler production.
The following outcome-based criteria and measurables are useful indicators of broiler welfare:
Mortality, culling and morbidity
Daily, weekly and cumulative mortality, culling and morbidity rates should be within expected ranges. Any unforeseen increase in these rates could reflect an animal welfare problem.
Gait
Broilers are susceptible to developing a variety of infectious and non-infectious musculoskeletal disorders. These disorders may lead to lameness and to gait abnormalities. Broilers that are lame or have gait abnormalities may have difficulty reaching the food and water, may be trampled by other broilers, and may experience pain. Musculoskeletal problems have many causes, including genetics, nutrition, sanitation, lighting, litter quality, and other environmental and management factors. There are several gait scoring systems available.
Contact dermatitis
Contact dermatitis affects skin surfaces that have prolonged contact with wet litter or other wet flooring surfaces. The condition is manifested as blackened skin progressing to erosions and fibrosis on the lower surface of the foot pad, at the back of the hocks, and sometimes in the breast area. If severe, the foot and hock lesions may contribute to lameness and lead to secondary infections. Validated scoring systems for contact dermatitis have been developed for use in slaughterhouse/abattoir.
Feather condition
Evaluation of the feather condition of broilers provides useful information about aspects of welfare. Plumage dirtiness is correlated with contact dermatitis and lameness for individual birds or may be associated with the environment and production system. Plumage dirtiness can be assessed as part of on-farm inspections, at the time of harvesting or prior to plucking. A scoring system has been developed for this purpose.
Incidence of diseases, metabolic disorders and parasitic infestations
Ill-health, regardless of the cause, is a welfare concern, and may be exacerbated by poor environmental or husbandry management.
Behaviour
Fear behaviour
Fearful broilers show avoidance of humans, and this behaviour is seen in flocks where animal handlers walk through the poultry house quickly when performing their tasks rather than moving more slowly while interacting with the broilers. Fearfulness (e.g. of sudden loud noises) can also lead to the broilers piling on top of, and even suffocating, one another. Fearful broilers may be less productive. Validated methods have been developed for evaluating fearfulness.
Spatial distribution
Changes in the spatial distribution (e.g. huddling) of the birds may indicate thermal discomfort or the existence of areas of wet litter or uneven provision of light, food or water.
Panting and wing spreading
Excessive panting and wing spreading indicates heat stress or poor air quality, such as high levels of ammonia.
Dust bathing
Dust bathing is an intricate body maintenance behaviour performed by many birds, including broilers. During dust bathing, broilers work loose material, such as litter, through their feathers. Dust bathing helps to keep the feathers in good condition, which in turns helps to maintain body temperature and protect against skin injury. Reduced dust bathing behaviour in the flock may indicate problems with litter or range quality, such as litter or ground being wet or not friable.
Feeding, drinking and foraging
Reduced feeding or drinking behaviour can indicate management problems, including inadequate feeder or drinker space or placement, dietary imbalance, poor water quality, or feed contamination. Feeding and drinking behaviour are often depressed when broilers are ill, and intake may be also reduced during periods of heat stress and increased during cold stress. Foraging is the act of searching for food, typically by walking and pecking or scratching the litter substrate; reduced foraging activity could suggest problems with litter quality or presence of conditions that decrease bird movement.
Feather pecking and cannibalism
Feather pecking can result in significant feather loss and may lead to cannibalism. Cannibalism is the tearing of the flesh of another bird, and can result in severe injury. These abnormal behaviours have multi-factorial causes.
Water and feed consumption
Monitoring daily water consumption is a useful tool to indicate disease and other welfare conditions, taking into consideration ambient temperature, relative humidity, feed consumption and other related factors. Problems with the water supply can result in wet litter, diarrhoea, dermatitis or dehydration.
Changes in feed consumption can indicate unsuitability of feed, the presence of disease or other welfare problems.
Performance
Growth rate (gr) - an index that indicates the average daily gain of weight per average broiler of a flock.
Feed conversion - an index that measures the quantity of feed consumed by a flock relative to the total live weight harvested, expressed as the weight of feed required to produce one kg of broiler body weight.
Liveability - an index that indicates the
percentage of broilers present at the end of the production period.
More commonly this indicator is measured as its opposite, mortality.
Injury rate
The rate of these injuries can indicate welfare problems in the flock during production or harvesting. Injuries include those due to other broilers (scratches, feather loss or wounding due to feather pecking and cannibalism) and those due to environmental conditions, such as skin lesions (e.g. contact dermatitis) and those due to human intervention, such as catching. The most prevalent injuries seen during catching are bruises, broken limbs, dislocated hips, and damaged wings.
Eye conditions
Conjunctivitis can indicate the presence of irritants such as dust and ammonia. High ammonia levels can also cause corneal burns and eventual blindness. Abnormal eye development can be associated with low light intensity.
Vocalisation
Vocalisation can indicate emotional states, both positive and negative. Interpretation of flock vocalisations is possible by experienced animal handlers.
Recommendations
Biosecurity and animal health
Biosecurity and disease prevention
Biosecurity programmes should be designed and implemented, commensurate with the best possible flock health status and current disease risk (endemic and exotic or transboundary) that is specific to each epidemiological group of broilers and in accordance with relevant recommendations in the Terrestrial Code.
These programmes should address the control of the major routes for disease and pathogen transmission:
direct transmission from other poultry, domesticated and wild animals and humans,
fomites, such as equipment, facilities and vehicles,
vectors (e.g. arthropods and rodents),
aerosols,
water supply,
feed.
Outcome-based measurables: incidence of diseases, metabolic disorders and parasitic infestations, mortality, performance.
Animal health management, preventive medicine and veterinary treatment
Those responsible for the care of broilers should be aware of the signs of ill-health or distress, such as a change in feed and water intake, reduced growth, changes in behaviour, abnormal appearance of feathers, faeces, or other physical features.
If persons in charge are not able to identify the causes of diseases, ill-health or distress, or to correct these, or if they suspect the presence of a reportable disease, they should seek advice from veterinarians or other qualified advisers. Veterinary treatments should be prescribed by a veterinarian.
There should be an effective programme for the prevention and treatment of diseases consistent with the programmes established by Veterinary Services as appropriate.
Vaccinations and treatments should be administered, on the basis of veterinary or other expert advice, by personnel skilled in the procedures and with consideration for the welfare of the broilers.
Sick or injured broilers should be humanely killed as soon as possible. Similarly, killing broilers for diagnostic purposes should be done in a humane manner in accordance with Chapter 7.6.
Outcome-based measurables: incidence of diseases, metabolic disorders and parasitic infestations, mortality, performance, gait.
Environment and management
Thermal environment
Thermal conditions for broilers should be appropriate for their stage of development, and extremes of heat, humidity and cold should be avoided. For the growing stage, a heat index can assist in identifying the comfort zones for the broilers at varying temperature and relative humidity levels.
When environmental conditions move outside these zones, strategies should be used to mitigate the adverse effects on the broilers. These may include adjusting air speed, provision of heat, evaporative cooling and adjusting stocking density.
Management of the thermal environment should be checked frequently enough so that failure of the system would be noticed before it caused a welfare problem.
Outcome-based measurables: behaviour, mortality, contact dermatitis, water and feed consumption, performance, feather condition.
Lighting
There should be an adequate period of continuous light.
The light intensity during the light period should be sufficient and homogeneously distributed to allow the broilers to find feed and water after they are placed in the poultry house, to stimulate activity, and allow adequate inspection.
There should also be an adequate period of continuous darkness during each 24-hour period to allow the broilers to rest, to reduce stress and to promote normal behaviour, gait and good leg health.
There should be a period for gradual adjustment to lighting changes.
Outcome-based measurables: gait, metabolic disorders, performance, behaviour, eye condition, injury rate.
Air quality
Adequate ventilation is required at all times to provide fresh air, to remove waste gases such as carbon dioxide and ammonia, dust and excess moisture content from the environment.
Ammonia concentration should not routinely exceed 25 ppm at broiler level.
Dust levels should be kept to a minimum. Where the health and welfare of broilers depend on an artificial ventilation system, provision should be made for an appropriate back-up power and alarm system.
Outcome-based measurables: incidence of respiratory diseases, metabolic disorders, eye conditions, performance, contact dermatitis and behaviour.
Noise
Broilers are adaptable to different levels and types of noise. However, exposure of broilers to sudden or loud noises should be minimised where possible to prevent stress and fear reactions, such as piling. Ventilation fans, feeding machinery or other indoor or outdoor equipment should be constructed, placed, operated and maintained in such a way that they cause the least possible amount of noise.
Location of farms should, where possible, take into account existing local sources of noise.
Outcome-based measurables: daily mortality rate, morbidity, performance, injury rate, fear behaviour.
Nutrition
Broilers should always be fed a diet appropriate to their age and genetics, which contains adequate nutrients to meet their requirements for good health and welfare.
Feed and water should be acceptable to the broilers and free from contaminants at a concentration hazardous to broiler health.
The water system should be cleaned regularly to prevent growth of hazardous microorganisms.
Broilers should be provided with adequate access to feed on a daily basis. Water should be available continuously. Special provision should be made to enable young chicks access to appropriate feed and water.
Broilers that are physically unable to access feed or water should be humanely killed as soon as possible.
Outcome-based measurables: feed and water consumption, performance, behaviour, gait, incidence of diseases, metabolic disorders and parasitic infestations, mortality, injury rate.
Flooring, bedding, resting surfaces and litter quality
The floor of a poultry house should preferably be easy to clean and disinfect.
The provision of loose and dry bedding material is desirable in order to insulate the chicks from the ground and to encourage dust bathing and foraging.
Litter should be managed to minimise any detrimental effects on welfare and health. Poor litter quality can lead to contact dermatitis and breast blisters. Litter should be replaced or adequately treated when required to prevent diseases in the next flock.
Litter quality is partly related to the type of substrate used and partly to different management practices. The type of substrate should be chosen carefully. Litter should be maintained so that it is dry and friable and not dusty, caked or wet. Poor litter quality can result from a range of factors including water spillage, inappropriate feed composition, enteric infections, poor ventilation and overcrowding.
If broilers are kept on slatted floors, where a very humid climate precludes the use of other flooring substrates, the floors should be designed, constructed and maintained to adequately support the broilers, prevent injuries and ensure that manure can fall through or be adequately removed.
To prevent injury and keep them warm, day-old birds should be placed on an appropriate type of flooring suitable for their size.
If day-old birds are housed on litter, before they enter the poultry house, a layer of uncontaminated substrate, such as wood shavings, straw, rice husk, shredded paper, treated used litter should be added to a sufficient depth to allow normal behaviour and to separate them from the floor.
Outcome-based measurables: contact dermatitis, feather condition, gait, behaviour (dust bathing and foraging), eye conditions, incidence of diseases, metabolic disorders and parasitic infestations, performance.
Prevention of feather pecking and cannibalism
Feather pecking and cannibalism are rarely seen in broilers because of their young age. However, management methods, such as reducing light intensity, providing foraging materials, nutritional modifications, reducing stocking density, selecting the appropriate genetic stock should be implemented where feather pecking and cannibalism are a potential problem.
If these management strategies fail, therapeutic beak trimming is the last resort.
Outcome-based measurables: injury rate, behaviour, feather condition, mortality.
Stocking density
Broilers should be housed at a stocking density that allows them to access feed and water and to move and adjust their posture normally. The following factors should be taken into account: management capabilities, ambient conditions, housing system, production system, litter quality, ventilation, biosecurity strategy, genetic stock, and market age and weight.
Outcome-based measurables: injury rate, contact dermatitis, mortality, behaviour, gait, incidence of diseases, metabolic disorders and parasitic infestations, performance, feather condition.
Outdoor areas
Broilers can be given access to outdoor areas as soon as they have sufficient feather cover and are old enough to range safely. There should be sufficient exit areas to allow them to leave and re-enter the poultry house freely.
Management of outdoor areas is important in partially housed and completely outdoors production systems. Land and pasture management measures should be taken to reduce the risk of broilers being infected by pathogens or infested by parasites. This might include limiting the stocking density or using several pieces of land consecutively in rotation.
Outdoor areas should be placed on well drained ground and managed to minimise swampy conditions and mud.
Outdoor areas should provide shelter for broilers and be free from poisonous plants and contaminants.
Protection from adverse climatic conditions should be provided in completely outdoors systems.
Outcome-based measurables: behaviour, incidence of disease, metabolic disorders and parasitic infestations, performance, contact dermatitis, feather condition, injury rate, mortality, morbidity.
Protection from predators
Broilers should be protected from predators.
Outcome-based measurables: fear behaviour, mortality, injury rate.
Choice of broiler strain
Welfare and health considerations should balance any decisions on productivity and growth rate when choosing a broiler strain for a particular location or production system.
Outcome-based measurables: gait, metabolic disorders, contact dermatitis, mortality, behaviour, performance.
Painful interventions
Painful interventions, such as beak trimming,
toe trimming and dubbing, should not be routinely practised on broilers.
If therapeutic beak trimming is required, it
should be carried out by trained and skilled personnel at as early an
age as possible and care should be taken to remove the minimum amount
of beak necessary using a method which minimises pain and controls
bleeding.
Surgical caponisation should not be performed without adequate pain and infection control methods and should only be performed by veterinarians or trained and skilled personnel under veterinary supervision.
Outcome-based measurables: mortality, culling and morbidity, behaviour.
Handling and inspection
Broilers should be inspected at least daily. Inspection should have three main objectives: to identify sick or injured broilers to treat or cull them, to detect and correct any welfare or health problem in the flock, and to pick up dead broilers.
Inspection should be done in such a way that broilers are not unnecessarily disturbed, for example animal handlers should move quietly and slowly through the flock.
When broilers are handled, they should not be injured or unnecessarily frightened or stressed.
Broilers which have an incurable illness, significant deformity or injury should be removed from the flock and killed humanely as soon as possible as described in Chapter 7.6.
Cervical dislocation is an accepted method for killing individual broilers if carried out competently as described in Article 7.6.17.
Outcome-based measurables: behaviour, performance, injury rate, mortality, vocalisation, morbidity.
Personnel training
All people responsible for the broilers should have received appropriate training or be able to demonstrate that they are competent to carry out their responsibilities and should have sufficient knowledge of broiler behaviour, handling techniques, emergency killing procedures, biosecurity, general signs of diseases, and indicators of poor animal welfare and procedures for their alleviation.
Outcome-based measurables: all measurables could apply.
Emergency plans
Broiler producers should have emergency plans to minimise and mitigate the consequences of natural disasters, disease outbreaks and the failure of mechanical equipment. Planning may include the provision of fail-safe alarm devices to detect malfunctions, backup generators, access to maintenance providers, alternative heating or cooling arrangements, ability to store water on farm, access to water cartage services, adequate on farm storage of feed and alternative feed supply and a plan for managing ventilation emergencies.
The emergency plans should be consistent with national programmes established or recommended by Veterinary Services. Humane killing procedures should be part of the emergency plan.
Location, construction and equipment of farms
The location of broiler farms should be chosen to be safe from the effects of fires and floods and other natural disasters to the extent practical. In addition farms should be sited to avoid or minimise biosecurity risks, exposure of broilers to chemical and physical contaminants, noise and adverse climatic conditions.
Broiler houses, outdoor areas and equipment to which broilers have access should be designed and maintained to avoid injury or pain to the broilers.
Broiler houses should be constructed and electrical and fuel installations should be fitted to minimise the risk of fire and other hazards.
Broiler producers should have a maintenance programme in place for all equipment the failure of which can jeopardise broiler welfare.
On farm harvesting
Broilers should not be subject to an excessive period of feed withdrawal prior to the expected slaughter time.
Water should be available up to the time of harvesting.
Broilers that are not fit for loading or transport because they are sick or injured should be killed humanely.
Catching should be carried out by skilled animal handlers and every attempt should be made to minimise stress and fear reactions, and injury. If a broiler is injured during catching, it should be killed humanely.
Broilers should not be picked up by their neck or wings.
Broilers should be carefully placed in the transportcontainer.
Mechanical catchers, where used, should be designed, operated and maintained to minimise injury, stress and fear to the broilers. A contingency plan is advisable in case of mechanical failure.
Catching should preferably be carried out under dim or blue light to calm the broilers.
Catching should be scheduled to minimise the time to slaughter as well as climatic stress during catching, transport and holding.
Stocking density in transportcontainers should suit climatic conditions and maintain comfort.
Containers should be designed and maintained to avoid injury, and they should be cleaned and, if necessary, disinfected regularly.
Outcome-based measurables: behaviour, vocalisation, injury rate, mortality rate at harvesting and on arrival at the slaughterhouse/abattoir.
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2016 ©OIE - Terrestrial Animal Health Code |
