The slaughter of broiler chickens involves stunning, neck cutting and bleeding out at rates of up to 15,000 birds per hour in large facilities, with welfare outcomes depending critically on stunning efficacy and line speed.
Broiler slaughter welfare depends on the combination of correct stunning, rapid killing and prevention of recovery between stunning and death. Water bath stunning at incorrect parameters causes pain without unconsciousness — the animal experiences the electric shock without losing consciousness. Multi-bird stunning creates additional risks from positional variation between birds. Controlled atmosphere killing, while requiring capital investment, eliminates shackling distress and provides more reliable unconsciousness across all birds regardless of body position. The volume of chickens slaughtered — billions annually — means that even small improvements in stunning efficacy translate to welfare benefits for enormous numbers of individual animals.