Objective measures of welfare in farming environments.

Welfare in farm animals is both difficult to define and measure. Definitions of welfare and the indicators of welfare which can be scientifically measured are discussed. These indicators are health, productivity, physiological and biochemical changes, and behavioural patterns; they can often be correlated from a husbandry system to give a good indication of the welfare status of the animals in the system. Most of the research work in this area has been done in the intensive pig and poultry industries, although the correlation of biochemical measures with husbandry procedures used in sheep and cattle has begun. It is difficult at this stage to develop a simple stress test that would take all the variables into account, but a change of any of the indicators will suggest further investigation is required. The most obvious to monitor is behaviour, as even a slight change can indicate a change in welfare status.