Early weaning of piglets at 21 days or less in commercial systems causes significant welfare problems for both sows and piglets, and later weaning produces measurable welfare improvements.
Commercial pig weaning creates a sharp welfare discontinuity. Piglets removed from their mothers at 21 days or earlier experience the loss of maternal contact, familiar social group, familiar environment, and milk nutrition simultaneously. The gut immune system at this age is immature, predisposing weaned piglets to post-weaning scours. Distress behaviors including increased aggression and prolonged vocalization indicate the welfare cost of early separation. Systems that allow weaning at older ages — 28-35 days — or use gradual weaning approaches produce piglets with better behavioral welfare, gut health, and reduced antibiotic requirements.