Domestic animals' fear of humans and its effect on their welfare

Many studies on pigs, poultry, and dairy cattle have shown that rough or av ersive handling of farm animals by people can substantially reduce the anim als' productivity and welfare. Some of this effect occurs because the anima ls become afraid, either of people in general, or of specific individuals a s a result of aversive handling. In this paper, we review a number of studi es showing that farm animals handled roughly or aversively learn to associa te the handling with people, and that this learned fear of people can have marked effects on production. The ability to recognize individual people ha s now been shown indisputably for many species of farm animals, although un der some circumstances, animals do not behave differently to different peop le. Animals' learned fear of individual people can markedly affect their pr oductivity. For example, in dairy cattle, the presence of an aversive handl er during milking can reduce milk yield and substantially increase residual milk. Pigs appear to use multiple cues to distinguish people, although vis ual cues are clearly important. Cows can readily learn to distinguish betwe en people wearing different colour clothes, but it is more difficult for th em to distinguish between people wearing the same colour. Furthermore, cows ' responses to people change markedly when clothing colour is changed, alth ough this does not seem to be true for poultry. However, animals' responses to people can be affected by the context. For example, cattle's learned re sponses to individuals can be strongly affected by the place they are in. W e finish with some suggestions as to how these results can be used to reduc e fear in farm animals. Crown copyright (C) 1999 Published by Elsevier Scie nce B.V. All rights reserved.