Weaning is one of the most stressful events in a pig's life. The timing, conditions and management of weaning profoundly affect piglet welfare and long-term health outcomes.
Weaning in commercial pig production imposes simultaneous stressors that collectively cause significant welfare harm. Piglets at 21-28 days are immunologically and physiologically immature for the abrupt transition from milk to solid food, social separation from the sow, and mixing with unfamiliar piglets. Post-weaning diarrhoea, which causes significant suffering and mortality, is substantially driven by the gut immaturity of early-weaned piglets. Research consistently shows that even a few additional days of nursing significantly improves welfare and health outcomes. The 28-day EU minimum was set partly on welfare grounds but represents a compromise with production economics rather than an optimal welfare standard. Extended suckling to 35 days or beyond would substantially improve piglet welfare at some production cost.