How chickens and turkeys are rendered unconscious before slaughter is one of the most significant animal welfare issues in food production, affecting billions of animals annually.
Electrical water bath stunning requires birds to be shackled upside-down while conscious — causing pain from the shackling position and occasional pre-stun electric shocks as birds flap and touch the water. Controlled atmosphere stunning (usually CO2 or inert gas) renders birds unconscious before shackling, eliminating this suffering. The welfare case for CAS over water bath stunning is strong and industry transition has been slow due to capital costs. Pre-stun handling improvements and monitoring systems also reduce suffering at large scale.