Pigs are highly social animals whose welfare depends on appropriate group management. Understanding how to reduce aggression enables welfare-positive group housing.
Pig social welfare depends on managing the inevitable aggression that occurs when pigs are mixed into new groups. The pig farming cycle — weaning, grouping, regrouping at different stages — creates repeated mixing events that cause severe fighting and associated welfare harm. Best practice involves minimizing mixing events, maintaining stable groups, providing adequate space for subordinate animals to avoid dominant ones, and ensuring sufficient enrichment to redirect behavior away from pen-mates. Farms that achieve stable social groups show lower stress indicators, better growth, and fewer injuries — making social management both a welfare and production benefit.