Broiler growing methods in the US are now closely monitored by the public, strongly driven by animal welfare concerns. A seminar was held earlier this year with the aim of defining acceptable production standards for both consumers and producers. Specialists expressed their views, ranging from breeding to growing and slaughter.
By Dr. Simon M. Shane, Durham, NC, USA
The US broiler welfare symposium was organised by the American Association of Avian Pathologists and sponsored by the American Veterinary Medical Association (AVMA). In her keynote address Dr. Gail Golab, Director of the Animal Welfare Division of AVMA, highlighted the conflicting expectations for animal care brought forward by the various stakeholders in the animal well-being debate. These include consumers, who need a wholesome, inexpensive supply of poultry meat, but who also want to be comfortable that animals are well cared for; domestic producers who depend on the well-being of their animals for success, but who also face financial constraints; animal protection activists, who range from those with a special interest in animals to those who are philosophically opposed to use of livestock for food/fibre; and legislators, who face a multitude of complicated and contentious issues on a daily basis and must respond to the needs of their constituents.
Pressure from the public
Although concern for animal welfare was firmly entrenched in the EU following the 1964 publication of Animal Machines, which precipitated the Brambell Committee recommendations, structured programmes for welfare assurance only emerged in the US during the mid 1980s. Organizations such as People for the Ethical Treatment of Animals (PETA) and the Humane Society of the United States (HSUS) and its various affiliates have exerted pressure on multi-national chain restaurants and supermarkets, urging them to force their suppliers to implement and enforce welfare standards. This resulted in a joint initiative by the National Council of Chain Restaurants (NCCR) and the Food Marketing Institute (FMI), which collectively control over 90% of poultry meat consumed in the US, to develop a set of welfare standards and review assurance programmes and processes. The programme was refined in consultations, resulting in acceptance of standards based on input and recommendations from a panel of scientists interpreting research on behaviour, pain, management procedures and alternative housing and equipment.
The Professional Animal Auditors Certification Organization (PAACO) was established to train and monitor the activities of auditors involved in assessing welfare through third party audits.
The major challenges facing the US industry involve interpretation of research, application of scientific principles, and developing new housing and technology to enhance welfare. Scientists, however, are not the definitive arbiters of welfare since it is necessary to engage a range of stakeholders, including consumers, legislators, administrators, producer associations and organizations arrayed against intensive livestock production.
The scientific approach
Dr. Suzanne Millman of Iowa State University stresses that although scientific knowledge should form the basis of production practices and legislation, ethical and moral considerations are important determinants of attitudes towards welfare and public perception of the industry. An American Farm Bureau survey revealed that 54% of respondents considered that welfare decisions should be based on science and 56% agreed that farm animal welfare decisions should be made by experts. A majority (76%) of respondents did not consider the price of food to be more important than the welfare of animals which were recognized as experiencing pain and discomfort. Since scientists disagree over the importance of specific measurements of flock welfare, many consumers rely on their moral compasses to establish their acceptance of industry practices and ultimately this influences their purchase decisions. Dr. Millman stresses the need for a multidisciplinary approach to assessing welfare and developing new technology. Adaptation of epidemiologic methods to assess stocking density, ventilation requirements, litter management and identifying risk factors, which detract from welfare and optimal performance, will receive greater attention in the future. Scientific evaluation of the physiology, behaviour and the affective state of flocks should be combined to resolve emerging issues, including aggression in breeder males, lameness in broilers, and disease that may conflict with the UK “Five Freedoms”, which mandate freedom from thirst, hunger, discomfort, pain, injury, fear and distress and deprivation of normal behaviour.
Genetics related to welfare
Approx. 50 years of intensive selection have markedly changed the growth potential, livability and feed conversion efficiency of broilers at both the parent and commercial broiler levels, according to Dr. Michael Martin of the North Carolina College of Veterinary Medicine. Selective breeding for traits of commercial significance have undoubtedly given rise to developmental and metabolic conditions which have welfare significance. Musculo-skeletal integrity may be impaired by the presence of tibial dyschondroplasia or angular limb deformities. Metabolic conditions include right heart failure with the acute manifestation as sudden death syndrome and a more chronic form presented as ascites. Deep pectoral myopathy, long recognized in heavy turkeys, now occurs in broilers harvested in excess of 3.5 kg live weight. Although these conditions are associated with progressive selection for specific commercial performance traits, amelioration by modifying housing equipment and management is possible. The prevalence rate of sudden death syndrome and ascites can be reduced by modifying lighting and feeding programmes. Changes in dietary specifications contribute to optimal growth when placing high-yield broiler strains. Sexual dimorphism between parent roosters and hens may lead to injury unless males are “de-spurred” as a component of chick service at the hatchery.
The hatchery perspective
Dr. Donna Hill is an international expert on hatchery design and management and is affiliated to HatchTech. She considers Best Management Practices that promote both welfare and flock performance. The trend toward hatcheries with an output of 1-2 million chicks per week has mandated mechanization of the entire process from removal of chicks from hatching trays through transport to farms. Hatchery equipment, which achieves efficient separation of chicks from debris, gentle conveying, counting, boxing, vaccination and service, has improved both efficiency and welfare. Key items incorporated into the design and operation of hatcheries include alarm systems in the event of power failure or deviation from preset temperature, emergency power generators, and controlled environment in areas for staging, processing and holding chicks. The design of hatchery equipment, especially conveyors, to avoid injury and ensuring the compatibility of individual modules with respect to processing rate are important components of the continuum of welfare from hatch to delivery. Monitoring of temperature, chick quality and the activities of workers contributes to acceptable handling to reduce trauma and stress. Special provisions must be made to humanely euthanize defective chicks. Service procedures such as manual vaccination, beak treatment and handling of chicks in small nonmechanized hatcheries must be under direct supervision of hatchery managers. Auditing of hatchery operations is based on a review of detailed records and direct observation with scoring of facilities and activities against a predetermined objective set of standards.
Vertical integration in the US broiler industry incorporates contract growers who receive chicks and feed and provide housing, equipment and labour, following management routines as specified by the integrator. In the past 10 years, adoption of Best Management Practices has resulted in clearly defined procedures to be followed by contractors. The supervision of broiler growing is facilitated by standardisation of housing, ventilation systems and equipment in the newer complexes. With houses of approx. 20,000 capacity, the average US complex producing 1 million broilers per week, operating an 8-week cycle will require 400 broiler houses. With an average farm size of three houses, a complex will place and deplete flocks from as many as 130 farms spread over a 10-30 mile radius from the central complex, which comprises the processing plant and a suitably located feed mill and hatchery.
Dr. Timothy Cummings of Mississippi State University reviewed standard procedures which contribute to welfare in broiler growing in the US. Considerations are incorporated into Standard Procedures for preparing houses to receive chicks. These include decontamination, either replacement or treatment and “topping” of litter, operation of brooders to ensure optimal temperature at the time of delivery of chicks and the correct placement of drinking and feeding systems consistent with the “Five Freedoms”.
Good housing conditions
Aspects of broiler growing which have profound welfare implications include selection of appropriate stocking density both in the brooding area and subsequent to 10-15 days when flocks are extended to the entire house to permit unrestricted access to feeders and drinkers. Ventilation is an important component with standards clearly defined for the four seasons. In the Southern-tier states, daytime temperatures during summer can exceed 40ºC and drop to –5ºC during winter nights. The welfare of flocks is enhanced by erecting modern housing costing in excess of US$150,000 per unit. These houses have solid side walls, tunnel ventilation with evaporative cooling pads, and sufficient insulation to maintain comfort within the house. Ventilation systems are computerized and incorporate loggers so that service staff can download data relating to temperature and operation of fans and cooling systems, which can in turn be correlated with weight gain, feed conversion and livability. Other issues relating to welfare include removal of defective chicks, which may show congenital abnormalities within the first two weeks, and then subsequently to cull broilers showing skeletal and locomotory abnormalities, which appear from the third week onwards.
Visiting flocks at least twice daily to remove moribund or dead birds, adjusting the height of feeders and drinkers, verifying correct operation of ventilation systems and ensuring that the moisture content of litter is consistent with freedom from ammonia production are required tasks. Most companies now use restricted lighting programmes both in terms of duration and intensity to reduce the incidence of leg deformities and right heart failure resulting from pulmonary arterial hypertension. Contractors and service staff are required to inform company veterinarians of any deviation from normal liveability or any unusual circumstance so that appropriate diagnostic procedures and corrective measures can be implemented.