Aggression in commercial pig production causes significant welfare harm through injury, stress, and resource competition, requiring proactive management strategies rather than reactive treatment of consequences.
Aggression in pigs is not an inherent problem of the species but a predictable consequence of management practices that violate their social and environmental needs. Frequent regrouping of unfamiliar animals, barren environments that redirect exploratory behavior toward pen-mates, and inadequate space that prevents subordinate animals from avoiding dominant individuals all create conditions where aggression escalates. Welfare-progressive pig production minimizes regrouping, maintains stable social groups, provides complex environments, and ensures space allowances that allow normal social behavior including conflict avoidance — addressing the cause of aggression rather than managing its consequences.