Commercial pig weaning occurs at 3-4 weeks of age — far earlier than natural weaning at 3-4 months. Early weaning causes significant stress to piglets and sows through abrupt maternal separation.
Early weaning is one of the most welfare-significant routine practices in commercial pig production. The vocalisation of sows and piglets at separation is acute and prolonged — both show distress responses that persist for days. Piglets weaned at 21 days are nutritionally and immunologically immature, making them more vulnerable to disease during the critical post-weaning period. The abrupt social disruption is compounded by simultaneous mixing of piglets from different litters, causing aggression. Post-weaning diarrhoea — a major welfare and production problem — is partly a consequence of gut immaturity and stress at weaning. Each week of additional weaning age produces measurable welfare improvements. Systems that allow 8-week or extended weaning produce piglets with significantly better welfare outcomes and reduced medication requirements.