The age at which piglets are weaned from their mothers is one of the most significant welfare determinants in pig farming. Early weaning at 21 days causes documented welfare harms to both sows and piglets.
Early weaning creates an acute welfare event — maternal separation — that causes documented distress in both generations. Sows show restlessness, attempting to locate piglets for 24-48 hours. Piglets removed from their mother before their immune systems are fully developed show higher rates of stress-related illness. The drive to nurse is deeply embedded — prematurely weaned piglets exhibit redirected nursing behavior on pen mates for weeks after weaning. A minimum 28-day weaning age — as required by some higher welfare standards — meaningfully reduces these welfare harms while still meeting commercial production requirements. The transition from 21- to 28-day weaning represents a tractable welfare improvement that does not require major husbandry changes.