Indicators of poor welfare.

The welfare of an individual is its state as regards its attempts to cope with its environment. Coping can sometimes be achieved with little effort and expenditure of resources, in which case the individual's welfare is satisfactory . Or it may fail to cope at all, in which case its welfare is obviously poor . Or, if the individual does cope with the conditions it encounters, this may be easy, with little expenditure of resources, or may be difficult taking much time and energy, in which case welfare is deemed to be poor . one approach to the improvement of welfare lies in the design of `housing systems' on the basis of either what animals choose to do in semi-natural environments (Stolba & Wood-Gush, 1984), or their choice as to their preferred conditions in experimental situations (Baldwin & Ingram, 1967 ; Hughes, 1976 ; dawkins, 1983) . The approach summarised here involves both the assessment of indicators of poor welfare, and the comparison of housing systems, or treatments, so as to recognise and excise the causes of poor welfare . The indicators of poor welfare are of two general types, the one demonstrating that an individual has failed to cope with an environment, the other indicating the effort involved and the extent of an individual's attempts at coping . Failure to cope with the effects of an environment may involve increased mortality, a reduction in the numbers of offspring surviving or a delay in the production of offspring . Sometimes these can be measured directly, but they may also be indicated by increases in the incidence of disease, reduced offspring size, reduced milk production or reduced growth rate . When using such welfare indicators it is the welfare of each individual rather than that of the group as a whole, which must be assessed . For example, if either growth rate, or reproductive success, are being measured, a shortage of food might lead to effects on all the individuals present which would indicate a decrease in welfare . However, it is more common, when animals are in groups, for the welfare of some animals to be good but for social factors to result in others failing to obtain sufficient food or in their being adversely affected in other ways . Whilst average growth rate, or reproductive output may be normal, the welfare of some individuals may be poor ; consequently, either the system should be changed, or alternative provision made for these individuals . Although certain parasite and pathogen infections have little effect on the host, the welfare of most diseased animals is poor and disease reduction is a most important part of welfare improvement . In addition to providing direct information about welfare, disease