Commercial pigs are weaned at 3-4 weeks of age — far earlier than the natural 12-17 weeks. Early weaning causes acute behavioral and physiological stress that increases disease susceptibility and causes lasting welfare harm.
Early weaning is a fundamental welfare compromise in commercial pig production. The developmental immaturity of 3-week-old piglets means their digestive and immune systems are not prepared for abrupt dietary transition and social disruption simultaneously. The resulting stress cascade increases susceptibility to disease, drives antibiotic use, and causes behavioral suffering that persists for days to weeks. Extending weaning age to 5-6 weeks improves welfare outcomes measurably. Providing complex solid feed in the days before weaning accelerates gut development. These interventions have modest costs relative to their welfare benefit and are required in several Scandinavian welfare systems.