Controlled atmosphere stunning (CAS) using inert gases avoids the handling stress and live shackling of water bath systems, with significant welfare advantages in poultry slaughter.
The shift from water bath to controlled atmosphere stunning represents one of the most significant available improvements in poultry slaughter welfare. Water bath systems require conscious birds to be shackled and inverted, causing pain, fear, and distress before the stunning event. CAS systems eliminate this pre-stun handling stress by rendering birds insensible in their transport containers. High CO2 systems have their own welfare concerns as birds may experience aversive respiratory distress before losing consciousness; inert gas systems using argon or nitrogen avoid this disadvantage. Supporting poultry processors that have invested in CAS creates direct economic incentive for industry transition.