CO2 stunning for pigs is widely used but welfare-compromised by the aversive gas exposure phase, driving research into alternatives including inert gas mixtures and improved CO2 protocols.
CO2 pig stunning welfare is an area where the current gold standard method has documented welfare limitations. The science showing that pigs avoid and show aversion to CO2 before losing consciousness has been available for decades, and represents a genuine welfare compromise in the most widely used pig stunning system globally. Inert gas alternatives that achieve unconsciousness without the aversive CO2 exposure are technically feasible but require capital investment in new systems. The welfare case for transition to inert gas stunning is strong, and consumer and regulatory pressure is the mechanism through which this transition will accelerate.