Letter to Mr Elliot Morley MP, of 16 April 2002, setting out FAWC's response to the publication of a statistical analysis of a major industry study on broiler chicken leg health

In its 1992 report on the Welfare of Broilers, FAWC declared that the problem of lameness was unacceptable and looked to the industry "to take steps to ensure a significant reduction in the numbers and severity of leg problems". As a result the industry set up a major study to collect data across a range of broiler production companies. The aim was to demonstrate over a 5-year period how the prevalence of lameness in the national flock was declining.

The Council welcomed the completion of this study in July 2000 but recognised that reliable conclusions could not be drawn from a simple comparison of a few average figures, which is all that was presented at that time. We recommended that the full dataset should be subjected to a comprehensive and rigorous statistical analysis in order to reveal the nature and reliability of the survey's findings. This recommendation was conveyed to the industry's representatives and included in my letter to you of 25 October 2000.

That statistical analysis has finally been undertaken by Professor Dirk Pfeiffer of the Royal Veterinary College and his report was submitted to the British Poultry Council in January of this year. We notice that the BPC placed the full draft of his report on their website last month. Now that its findings have been placed in the public domain, therefore, I am able to advise you of the Council's position in regard to the industry study and our current views on the welfare problem of lameness in broilers - which, in line with our normal practice, we will make public.

FAWC appreciates the substantial effort that the industry committed to its survey, undertaking it in good faith and, despite the practical difficulties, adhering as closely as possible to the methodology set out following its initial discussions with the Council in 1993. We understand that delays in data collection, restructuring within the industry and the loss of companies at various times over the intervening years, together with other operational problems, made it difficult to achieve the rigid adherence to the study protocol and the kind of consistency in the dataset, both within years and over time, that normal research methodology would seek. Nevertheless, a unique and comprehensive dataset was assembled and the analysis in the report is greatly welcomed. We look forward to the publication of the findings in a reputable peer-reviewed journal, the necessary final step in subjecting the results to critical appraisal and gaining objective acceptance amongst the scientific community.

A number of criticisms will inevitably be levelled at the study - for example that the 'gait scoring' methodology is imprecise, that data collection was not by independent observers, and that assessments were not all made as close to slaughter date as intended; however, we consider it unlikely that, within the large sample context in which the survey was undertaken, such deficiencies could have resulted in any substantial bias in the results. One major criticism is that the measures of lameness could have been biased downwards because the sampling units (companies, farms and sheds) were selected by the industry itself and not by the standard objective methods used in statistical trials. The report recognises this weakness of what it calls "convenience sampling", but draws no conclusions as to whether or not the study was representative of the national British broiler population. This is unfortunate, and FAWC is understandably uncomfortable making judgements in a situation where the prevalence levels of 2-3% measured in this industry study stand so much at variance with the 25-30% quoted from other (more restricted) studies.

Nevertheless, FAWC accepts a major statistical conclusion from the report that there has been a decline in the incidence of leg weakness over the period of the study, which is the primary outcome we looked to the industry to deliver following our 1992 Report. Anecdotal evidence and claims by the industry concerning changes in genetic selection criteria, housing, environment, production management techniques, etc. help to reinforce the view that this is a plausible conclusion.

However, the prevalence expressed as an average across the whole industry is an inadequate indicator of the existence of leg problems, and so the simple 'headline' findings from the report do not relieve FAWC of its longstanding concern over the welfare problem of lameness in broiler chickens. We believe there is a continuing need for explicit attention and action to be directed at this issue. It is those cases where the incidence of lameness is higher than it need be that define the existence of a significant welfare problem, and in this respect the more detailed findings of the survey still reveal major areas for concern.

When looking at the figures in more detail it is clear that on some broiler production units lameness prevalence was clearly unacceptable. The report notes instances where as many as 28% of birds in one shed were lame, and others where, within a production unit (i.e. across multiple flocks), the incidence was over 11%. It notes, too, that some companies tested were consistently worse than others in the levels of leg weakness recorded. By contrast other examples were found where lameness was measured to be extremely low - probably as low as it is practically possible to achieve in this production process.

FAWC's view is that these latter cases represent achievable best practice, which must be considered as the only acceptable standard. Any flocks, farms or companies where the prevalence of lameness exceeds this best practice level must become the focus for attention and immediate remedial action - by the SVS, the flock managers, the companies and the industry body - to ensure that emphasis on minimising this welfare problem is consistently maintained.

In this respect it is the definition of achievable best practice together with appropriate management action that underpin the necessary approach to resolving the longstanding problem of poor leg health in broilers. An important contributor to the information needed to achieve this resolution will be the Defra funded major research study into the prevalence, risk factors and management practices associated with lameness in broilers that we pressed for in our letter to you in October 2000. We appreciate the substantial resource that Defra has committed to this project, welcome the industry's declared willingness to co-operate fully with the researchers in pursuing the enquiry in a practical context, and are pleased that it is now under-way. FAWC is also encouraged that the breeders are focussing more attention on selection for leg strength in addition to the conventional criteria of commercial productivity.

In the meantime, we recommend that the SVS directs substantial effort to completing its modified poultry registration scheme and instituting a widespread programme of visits to broiler units. Wherever flocks are considered to demonstrate noticeable problems of lameness a full examination of records and management practices should be initiated. Evidence of a remedial action plan by the company should be sought, and the production unit made subject to frequent random inspections until the SVS is satisfied that no sustained leg problems are occurring in the unit.

The Council believes that it is only by collective recognition of the problem, joint effort by all the interested parties to better understand the problem and take appropriate action, and the industry's continued acceptance of its responsibility to ensure that its production methods genuinely protect the welfare of birds, that our concerns in this area will be relieved and that consumers and society as a whole will be reassured. We will continue to attach a high priority to this issue, and look forward to seeing substantial welfare benefits as the results of the Defra-funded research study emerge and become established in management practice.

FAWC Chairwoman
April 2002