The EU ban on individual sow stalls during gestation (with limited exceptions) has improved welfare for millions of sows, with group housing systems providing better welfare outcomes when well-managed.
Individual gestation stalls prevent sows from turning around or performing natural behaviors for periods of months during each reproductive cycle, causing chronic frustration, muscle atrophy, and psychological stress. Stereotypic behaviors are highly prevalent in stalled sows. Group housing, when well-managed, significantly improves welfare by allowing exercise, social interaction, and behavioral expression. However, poorly managed group housing can cause welfare problems from social aggression, competition for resources, and injury. Sow welfare in group housing depends critically on adequate space, appropriate group sizes, and management practices that minimize aggression.