36. In this section we discuss some of the main welfare issues which relate to birds in all systems. Our recommendations for specific systems follow in Part V.
37. A detailed review of welfare issues, with references to scientific publications, was provided by the European Commission's Scientific Veterinary Committee in its Report on the Welfare of Laying Hens in October 1996. This followed an earlier report published in 1992. We have carefully studied both reports.
38. In evaluating the welfare of laying hens, FAWC has taken into account the views of organisations and individuals with knowledge and experience of commercial production as well as the results of scientific research. It has not always been easy to reconcile information derived from different sources. Scientific research is good at isolating specific effects stemming from particular causes but may be less effective in helping us understand the complex interrelationship between the various parameters affecting commercial production. Behavioural science is good at answering some types of question (e.g. are hens motivated to perform particular types of behaviour?) but less effective at others (e.g. how much does a hen suffer when deprived of a resource?). During our review we found ourselves repeatedly faced with conflicting answers to questions such as: is it better for the welfare of hens for them to have a dust bath if they also have to endure high atmospheric dust levels with possible health effects?
39. Most of the systems commonly used to keep hens in this country can provide substantial parts of the Five Freedoms set out in Part I but no one system meets all of the criteria. Remembering that the Five Freedoms are ideals rather than minimum standards, failure to fulfil them in total does not mean that support for any system should be withdrawn. However, we believe that every effort should be made to keep hens in accordance with these broad principles and our approach required us to maintain a balance between the various welfare advantages and disadvantages of each system.