Weaning is one of the most stressful events in a pig's life, combining maternal separation, dietary change, and social mixing. Managing this transition well is a key welfare priority.
The welfare impact of early weaning in commercial pig production is substantial and multi-dimensional. The simultaneous occurrence of maternal separation, gut flora disruption from dietary change, and social stress from mixing with unfamiliar piglets creates a perfect storm of stressors with measurable physiological and behavioral consequences. Post-weaning diarrhea — driven partly by gut barrier disruption from weaning stress — is a leading cause of morbidity in young pigs and requires extensive antibiotic intervention in many systems. Extended weaning age, where economically feasible, dramatically reduces all dimensions of weaning stress. Where early weaning is unavoidable, mitigation strategies including familiar bedding provision, phased dietary transition, and minimizing social mixing reduce the welfare burden.