Group pig housing offers significant welfare benefits over individual confinement but requires careful management of aggression during mixing events.
Pig social housing creates a welfare management challenge: the benefits of social interaction, exercise, and behavioral expression in group settings are substantial, but mixing events cause intense, sometimes severe aggression that represents acute welfare harm. The optimal welfare approach minimizes mixing events by forming stable groups early and maintaining them consistently, while investing in adequate space, enrichment, and management infrastructure that allows subordinate pigs to escape dominant conspecifics. The alternative — individual confinement — avoids mixing aggression but creates chronic welfare deprivation. The evidence clearly favors well-managed group housing over confinement when mixing events are appropriately managed.