Pre-slaughter stunning practices determine whether billions of chickens lose consciousness before death or experience painful slaughter while conscious.
Pre-slaughter stunning is the welfare intervention with the largest direct impact on how chickens experience death. The difference between effective stunning that renders a bird insensible before death and ineffective or absent stunning means the difference between a welfare-neutral death and a painful one. The US is notable among developed countries in not requiring poultry stunning under its federal humane slaughter law. Water bath electrical stunning used in most US plants has documented failure rates. Controlled atmosphere killing using inert gases provides more reliable insensibility. Regulatory reform to require effective stunning for all poultry would be among the most impactful single welfare policy changes available.