Commercial pig production typically weans piglets at 3-4 weeks of age — far earlier than the natural weaning age of 3-4 months — causing significant welfare harms to both piglets and sows.
The welfare costs of early pig weaning are well-documented on both sides of the sow-piglet relationship. Sows separated from piglets at 21-28 days show vocalization, restlessness, and mammary discomfort from abrupt milk cessation. Piglets separated this early lack immunological maturity, adequate behavioral development, and the nutritional transition that natural weaning provides. Post-weaning stress manifests as belly nosing (oral fixation behavior), tail biting, and increased disease susceptibility. The motivation to continue suckling is thwarted, causing frustration and distress. Welfare-focused pig production increasingly uses longer lactation periods with enrichment, and some premium systems maintain piglets with sows until 35-42 days, dramatically improving outcomes.