Effects of food level and straw provision during pregnancy on sow performance and responses to an adrenocorticotrophic hormone challenge

In commercial practice, almost all pregnant sows are fed on restricted feeding regimes. Operant conditioning studies suggest that this results in the animals being food motivated for most of the day (Lawrence et at., 1988), a behavioural state which, in relatively barren environments, has been associated with the development of abnormal stereotypic behaviour (Spoolder et al., 1995). Straw provision reduces the development of stereotypies, possibly reflecting reduced (physiological) stress levels. In addition, it may result in lower nutritional requirements (Simmins et al., 1994).