The slaughter of over 9 billion chickens annually in the US involves methods that raise significant welfare concerns at massive scale.
Poultry slaughter welfare affects more individual animals than any other farming practice worldwide. In the US, the standard method involves live-hanging chickens upside down on shackle lines, causing pain and wing injuries, before water bath electrical stunning and mechanical throat cutting. Research has documented numerous welfare failures including live birds entering scalding tanks. Controlled atmosphere killing, which exposes birds to a gradually increasing concentration of inert gas or CO2, allows birds to remain in their transport containers and become unconscious more humanely. Many European countries and some US operations have adopted gas killing. Regulatory reform in the US to require gas killing would dramatically reduce poultry slaughter suffering.