CO2 stunning of pigs is the most widely used commercial method but causes significant aversive experiences before loss of consciousness. Understanding alternatives drives welfare reform in the pork industry.
CO2 stunning of pigs represents one of the most significant known welfare harms in food production, affecting hundreds of millions of pigs annually in Europe alone. The evidence of aversion - vocalisation, escape attempts, and distress behaviours during the induction phase - is robust and accepted by welfare scientists. Alternatives exist but require capital investment and regulatory change. Consumer pressure on food companies to commit to higher-welfare stunning standards, combined with regulatory reform requiring transition away from high-concentration CO2, represents the pathway to eliminating this documented welfare harm at scale.