The effect of space restriction and provision of toys during rearing on the behaviour, productivity and physiology of male pigs (1993)

Pearce, G. P., Paterson, A. M.

Abstract

These results show that reducing the space allowance to below the pigs' spatial preference caused chronic stress which impaired efficiency of feed utilisation and resulted in significantly reduced growth rates. This level of crowding also resulted in behavioural changes which may be indicative or reduced welfare. Although enriching the pigs' rearing environment with toys [chains, bars, cloth straps, tyres, etc.] did not alleviate the effects of crowding on the animals' growth rate, it did significantly increase the amount of exploratory behaviour as well as reducing the animals' responsiveness to novel stimuli (both objects and humans) at the end of the rearing period.