THE EFFECT OF AGE AT WEANING AND POST-WEANING ENVIRONMENT ON THE BEHAVIOR OF PIGS

In order to investigate the effect of age at weaning and the post-weaning environment on the behaviour and health of piglets, litters were weaned at 4 or 6 weeks of age and either kept in their farrowing pen or housed in flat decks (2 x 2 factorial design with a total of 24 litters). At 9 weeks of age all litters were moved to standard pens for fattening pigs. Behavioural observations and recording of lesions were undertaken at 8 and 12 weeks of age. At 8 weeks piglets weaned in flat decks spent more time lying than those weaned in the farrowing pen (1080 vs. 1026 min per day, p < 0.0 1), and piglets weaned at 6 weeks spent more time lying than those weaned at 4 weeks (I 083 vs. 1026 min per day, p < 0.0 1). Direct observations showed that piglets weaned in flat decks were sniffing/rooting pen mates, pen fittings and the floor, and chewing/nibbling pen mates and tail-biting significantly more than piglets weaned in the farrowing pen. The age at weaning was of minor importance for the frequency of these behaviours. At 12 weeks, when moved to standard fattening pens, very few of these differences persisted. However, the frequency of massaging and sucking pen mates was higher amongst piglets weaned at 4 weeks compared to 6 weeks, and also somewhat higher among piglets weaned in farrowing pens compared to flat decks. The piglets weaned in flat decks had a higher frequency of belly and tail lesions than piglets that remained in the farrowing pen. These findings suggest that the post-weaning environment has a major influence on the frequency of abnormal behaviours in weaned piglets, but that the observed differences disappear when the piglets are moved to standard fattening pens with bedding.