Animal welfare research is regularly promoted as providing information on practical welfare issues which assist policy-makers, but what is the reality? One of the key issues in the development of legislation, policy, and assurance programmes is how welfare can be assessed in an objective, practical and cost-effective way. Science is but one part of animal welfare policy but is the key in welfare assessment. The challenge is to develop policy standards that achieve welfare outcomes consistent with current scientific thinking, are consistent with good practice, meet societal expectations for the welfare of animals, are readily understood and accepted by those who must abide by them, and are effective tools for those who have to enforce them. Policy must strike a balance among these often conflicting scientific, social, ethical and production management considerations and must remain relevant in an environment of constant change. We have concluded that these objectives are best met by writing standards as welfare outcomes to be achieved, with each outcome accompanied by indicators by which achievement of the outcome can be measured or objectively assessed. We will illustrate how such science-based policy is being developed in New Zealand. Some of the challenges for policy makers are:
1. keeping up with the latest science;
2. being able to understand and interpret the science. How could science information be packaged to assist 'evidence-based' policy?
3. what to do when the science is not available (e.g. pain of banding dog tails) or
4. when science does not support popular views or wishes (e.g.layer hen cages vs free range)?
5. what to do when there are conflicting interpretations of scientific research?
In order to improve animal welfare, people in policy and science must better understand these differing issues and work together.