Effects of environmental enrichment on behaviour and reproductivity of growing pigs (1995)

Beattie, V. W., Walker, N., Sneddon, I. A.

Abstract

Enriching the environment [extra area with peat and a straw hopper; pigs in enriched environments had more than four times the floor space of pigs in barren environments] reduced both the amount of time pigs spent inactive and the time involved in harmful social and aggressive behaviour. Tail biting was absent from the enriched environment but four pigs were removed from barren pens with severe tail damage. Pigs housed in enriched environments spent longer durations in exploratory behaviour than those in barren housing. .... Enriched piglets demonstrated approximately a ten fold increase in playful behaviour compared to barren piglets.... The shorter periods of time spent in exploratory behaviour by pigs in the barren environment were complimented by higher durations of harmful social behaviour, supporting the argument that pigs in the absence of substrates use penmates as substitutes. ... These results indicate that welfare is improved by enrichment with substrates and suggests that barren pens should be modified to provide these facilities. ... It is pen design rather than merely the addition of toys that stimulates more natural behaviour.