The method used to stun poultry before slaughter has major welfare implications for billions of birds annually. Understanding the welfare science behind different stunning approaches drives better industry standards.
Poultry slaughter welfare affects an incomprehensible number of individual birds - tens of billions annually whose experiences in the final minutes of their lives depend on the adequacy of stunning systems. The welfare problems with conventional water bath stunning - including birds entering the stunner conscious due to incorrect shackling, and the stress of inversion and shackling itself - are well documented. Controlled atmosphere stunning systems eliminate these specific welfare problems but introduce others, particularly with CO2. Inert gas systems using nitrogen or argon appear most welfare-positive in research but require capital investment. Consumer and regulatory pressure for better slaughter welfare is driving gradual improvement in this critical welfare bottleneck.