There has been a trend in North America towards very early weaning of piglets combined with a segregation of the piglets from the sow in a system known as Segregated Early Weaning (SEW). This paper investigates the effects of very early weaning on piglet behaviour. In order to determine the effects of weaning age on piglet behaviour, litters of piglets were randomly assigned to be weaned at 7, 14, and 28 days of age. In each of three trials, piglets from three litters were mixed into two pens of 10 piglets per weaning age (six replicates per treatment, N=180). Pens were video-taped for 2 days immediately post-weaning and periodically until piglets were 6 weeks of age. There were marked differences in the behaviour of the piglets weaned at the different ages. Piglets weaned at 7 days spent more time belly-nosing (P<0.05), showed more escape behaviour (P<0.005), and spent less time interacting with neighbours …