Animals show considerable individual variation in many behaviour patterns such as feeding and mating behaviour. Often, this individual variability is ignored in favour of a more general description of the population. However, this may mask important information regarding the causes and functions of this individual variability. Behavioural work on other species has suggested that individuals tend to respond actively or passively to environmental challenge. It is of interest to know if a similar dimension of responsiveness exists in pigs as it may serve, amongst other things, to explain the considerable individual variability in pigs responses to putitive stresses such as tethered housing. This paper describes a series of tests made of behavioural responsiveness in pigs to assess the extent of consistent variability in individuals responses to a wide variety of environmental challenges.

The subjects were two groups [Group A and B: n = 26 and 36 respectively) of modern hybrid non-pregnant gilts [Cotswold Pig Development Company Ltd, UK). Initially, the gilts were subjected to a number of tests of behavioural responsiveness at the Cotswold unit.