Is belly nosing redirected suckling behaviour?

Through two experiments, we examined whether individual piglets' behaviour on the sow during nursing is related to post-weaning oral and ingestive behaviour. Specifically, we wanted to determine whether piglets with high suckling motivation during the nursing period are predisposed to developing belly nosing after weaning. An additional aim was to determine how piglets' growth relates to pre- and post-weaning behaviour. In Experiment 1, 95 individual piglets from 16 litters were observed before weaning for the occurrence of suckling behaviour during and between nursing bouts on three separate days. These piglets were mixed with unfamiliar conspecifics at weaning (15 days of age) and housed with either a nipple or a push-lever bowl drinker. The occurrence of belly nosing and related oral-nasal behaviour patterns was quantified from video recordings. Piglets were weighed at birth, weaning and at days 7, 14 and 19 after weaning. There was a negative relationship between pre-weaning suckling behaviour and post-weaning belly nosing when pigs were housed with a bowl drinker (P < 0.10) and between suckling and penmate-directed behaviour when pigs were housed with a nipple drinker (P < 0.05). Belly nosing tended to be negatively correlated with post-weaning average daily gain (P < 0.10). In Experiment 2, other post-weaning ingestive behaviour patterns were included in a principal components analysis (PCA) for a more in-depth look at the relationships among pre-weaning suckling and post-weaning behaviour patterns. Sixty-six piglets from seven litters were observed before weaning on three separate days and weaned at 21 days. Belly nosing, penmate and object nosing, along with maintenance behaviour patterns were observed from video recordings. Piglets were weighed at birth, weaning and at days 7, 14 and 21 after weaning. Piglets that belly nosed also performed penmate nosing. These piglets tended to be smaller at birth (P < 0.10) and weaning (P < .10) and grew slower after weaning than their littermates (P < 0.01). They also performed less suckling behaviour during nursing bouts. Piglets that spent more time at the feeder after weaning also performed more object-directed nosing. These piglets grew faster before (P < 0.01) and after weaning (P < 0.10) and were heavier at weaning than their littermates (P < 0.01). Results from both experiments indicate that belly nosing is not predicted by pig pre-weaning suckling behaviour. However, belly nosing may be similar to the final massage of suckling behaviour in the sense that the behaviour represents the piglets' nutritional need.