Pigs are highly social animals with complex dominance hierarchies. Housing design that accommodates their social needs reduces aggression and improves welfare for the whole group.
Pig social behaviour is complex and the management of social groups is a major welfare lever. Commercial practice often involves repeated mixing of unfamiliar pigs at weaning, moving between units, and at slaughter grouping — each mixing event triggers a period of intensive fighting with welfare costs for the whole group. Systems that maintain stable social groups from birth to slaughter, provide adequate space and resources to reduce competition, and avoid unnecessary regrouping significantly improve welfare outcomes. Space allowance per pig is directly related to aggression levels — overcrowding forces confrontation that stable-group pigs would naturally avoid.