Pituitary-adrenal activation in pre-parturient pigs (Sus scrofa) is associated with behavioural restriction due to lack of space rather than nesting substrate (2002)

Jarvis, S., Calvert, S. K., Stevenson, J. et al.

Abstract

Space also had an effect on ACTH and cortisol levels ... with C [crate] gilts having higher levels than P [pen] gilts, irrespective of straw availability. ... There was no effect of straw on ACTH or cortisol levels. .. It appears that increased space, perhaps through allowing locomotion, increases substrate-directed behaviour of pre-parturient gilts. When space is available but straw is absent, pre-parturient gilts redirect their nest-building behaviour to the floor. The ability to express substrate-directed behaviour as a result of increased space is reflected in lower levels of indicators of physiological stress.