Pigs are highly social animals that form stable relationships and suffer when repeatedly mixed with unfamiliar individuals. Understanding pig social needs is essential for designing humane farming systems.
Commercial pig production routinely disrupts pig social bonds at multiple points: at weaning when piglets are separated from sows; at regrouping when pigs from different litters are combined for growing; and sometimes at finishing when animals are sorted for slaughter. Each mixing event triggers a period of serious aggression as pigs establish new hierarchies, causing injuries, stress, and welfare setbacks that persist for days. The solution is well-established: maintaining stable social groups throughout the production cycle dramatically reduces aggression and improves welfare. The barriers are primarily management and facility design rather than fundamental incompatibility with commercial production. Progressive producers are demonstrating that stable grouping is both achievable and associated with better health and growth outcomes.