The effects of weaning at 7, 14 and 28 days on piglet behaviour

Abstract

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 ( P<0.005), feeding ( P<0.05), and nosing and chewing objects ( P<0.0005) compared with piglets weaned at 14 or 28 days. Piglets weaned at 14 days exhibited more belly-nosing behaviour ( P<0.05) and spent less time feeding directly following weaning than did those weaned at 28 days ( P<0.05). They also spent more time nosing and chewing pen-mates than did the piglets weaned at either 7 or 28 days ( P<0.05). Times spent engaged in aggression and aggression at the feeder and drinker and lying were similar in piglets across weaning age. At 6 weeks of age, the piglets weaned at 14 and 28 days were significantly heavier than piglets weaned at 7 days ( P<0.05). These results suggest that weaning piglets on or before 14 days of age may result in reduced performance and the development of behaviour patterns that either cause, or are indicators of, reduced welfare.