The method used to stun poultry before slaughter has significant welfare implications, with controlled atmosphere stunning offering advantages over conventional water bath electrical stunning.
Poultry stunning welfare is a case where a clearly better welfare option exists and is being adopted progressively through market pressure. Conventional water bath stunning requires birds to be hung upside down while conscious - a procedure that causes acute stress demonstrated by wing flapping, heart rate increases, and behavioral distress. The stunning itself provides unconsciousness when adequate current is applied, but the inverted livehanging phase before stunning is unavoidably welfare-compromising. Controlled atmosphere stunning in transport crates avoids this entirely by stunning birds before any livehanging occurs. The most welfare-positive systems use low-oxygen inert gas mixtures that provide unconsciousness without the aversive sensory experience of high CO2. Consumer and retailer pressure has driven significant industry transition.