Piglets in commercial systems are weaned at 21-28 days, far earlier than the natural weaning age of 12-17 weeks. The welfare implications of early weaning are significant and require mitigation.
Early weaning causes significant welfare compromise through immune system immaturity, gut development disruption, and social adjustment stress simultaneously. Twenty-one-day-old piglets have immature immune systems relying on continued maternal antibody provision. The stress of early weaning, combined with diet change and social mixing, creates the conditions driving post-weaning diarrhoea. Twenty-eight-day weaning substantially reduces these welfare problems by allowing greater immune and gut development before the transition. The welfare benefit of even one additional week of maternal nursing is measurable.