Effective stunning before slaughter is fundamental to poultry welfare. Water bath electro-stunning, CAS (Controlled Atmosphere Stunning) and their welfare implications are central to slaughter welfare debates.
Slaughter welfare is the final welfare test for animals raised in any production system. A chicken that has lived its entire life in excellent welfare conditions can still experience significant suffering at slaughter if stunning is ineffective or shackling causes pain before consciousness is lost. The evidence shows that stunning failures are more common than regulators and industry have historically acknowledged. CAS systems eliminate pre-stun shackling welfare harms and can achieve equivalent unconsciousness outcomes, but CO2 is aversive. Multi-phase CO2 systems (low initial concentration rising slowly) or inert gas systems offer better welfare profiles. Mandatory CCTV monitoring provides the oversight mechanism that deters welfare violations.