Slaughter is the final welfare event for billions of poultry annually, and the methods used at each stage — catching, transport, shackling, stunning, and killing — have significant implications for the suffering animals experience.
Poultry slaughter welfare involves multiple sequential welfare-critical points. Catching — the process of collecting birds from sheds at night — causes acute fear and physical injury when birds are grabbed roughly, stacked too deeply in catching machines, or transported in poorly designed modules. Shackling live birds inverted by the legs causes distress from the inversion posture and pain from struggling against the restraint. Electrical water bath stunning, when properly applied, renders birds insensible rapidly, but equipment calibration failures leave a proportion of birds entering the killing blade while still conscious. Controlled Atmosphere Killing, which stuns birds in their transport containers before shackling, eliminates live shackling and reduces the welfare insult of the final stages — but gas mixtures using high-concentration CO2 are themselves aversive before unconsciousness. The most welfare-positive approach — multi-phase inert gas stunning or very low CO2 concentrations — reduces aversion at the cost of process time. Consumer and regulatory pressure for adoption of higher-welfare slaughter methods represents one of the most accessible leverage points for improving the final welfare of the greatest number of animals.