The welfare of broiler chickens in the final minutes of their lives depends critically on stunning effectiveness, which varies significantly between methods and individual birds.
Broiler slaughter welfare involves a series of procedural steps each of which has distinct welfare implications: live hanging causes measurable pain and fear; stunning renders birds insensible if effective; neck cutting causes death if the stun was adequate. Failures at any step translate directly into suffering for individual birds. The welfare improvement trajectory in poultry slaughter is toward systems that eliminate live hanging entirely — controlled atmosphere stunning in transport modules — and that use gas combinations producing the most welfare-positive induction of unconsciousness. The scale of broiler production makes even small improvements in stun effectiveness significant: a 1% improvement in stun adequacy for 9 billion birds annually represents 90 million fewer birds experiencing consciousness during killing. Consumer-driven corporate commitments to controlled atmosphere killing are the fastest path to meaningful welfare improvement at this scale.