Group housing for pigs is increasingly standard but welfare outcomes depend critically on group composition, space allowance, and resource provision.
Group housing enables natural social behavior in pigs but creates welfare challenges from competition and aggression without appropriate management. Stable groups, adequate space, sufficient feeding space, and structural complexity are the management foundations for welfare-positive group housing. Poorly managed group housing can cause more welfare harm through aggression than well-managed individual housing, making management quality the key variable.