Pigs are highly social animals that thrive in stable group structures. Managing group composition and space allowances to minimize aggression while supporting social welfare is central to modern pig production welfare.
The welfare implications of pig group management are bidirectional: stable groups allow positive social interactions including play and mutual grooming, while disrupted groups experience intense aggression that causes injury and chronic stress. Minimizing the frequency of group mixing and providing adequate space and pen complexity reduces the welfare harm of aggression. Feeding system design in group sow housing is critical — competition at feeding stations is a major source of chronic stress in group systems. Electronic sow feeding systems that allow individual feeding access significantly reduce feeding competition and improve welfare outcomes compared to floor or trough feeding in groups.