Carbon dioxide gas stunning of pigs is widely used but causes significant aversion and distress before loss of consciousness, driving research into more humane alternatives.
CO2 stunning for pigs represents one of the clearest known welfare failures in industrialized slaughter. The science is unambiguous: pigs find high-concentration CO2 extremely aversive and struggle for up to a minute before losing consciousness. Inert gas alternatives that produce unconsciousness without the burning sensation of CO2 are technically and commercially available. The barrier to transition is primarily economic - CO2 systems are cheaper - rather than technical. Consumer and regulatory pressure are the drivers of change.