The effect of food level and housing on the development of stereotypic behaviour in tethered sows (1990)

Terlouw, E. M. C., Lawrence, A. B., Lindstrom-Nielsen, B. et al.

Abstract

It is often assumed that physical restraint and lack of stimulation are the major stressors for intensively housed sows. ... At all times of the day, low-fed gilts were more active than high-fed gilts, spending more time nosing the trough and floor, drinking and manipulating the chain. Over pregnancy, the low-fed gilts spent an increasing proportion of time on these activities and showed a significant increase in feeding rate. No such increases were observed in high-fed gilts. Low-fed loose-housed gilts had significantly higher post-feeding levels of chain chewing than low-fed tethered gilts, possibly owing to social stress. These results show that the frustration in feeding behaviour causes by low food allowances increases with time and is not diminished simply by providing freedom of movement.