Stunning methods used in poultry slaughter vary widely in their welfare efficacy, with water bath electrical stunning and controlled atmosphere systems differing significantly in animal experience.
The welfare of billions of birds at slaughter depends critically on stunning efficacy — whether birds lose consciousness before experiencing pain. Water bath stunning systems that allow birds to be hung shackled while conscious before stunning are particularly problematic. Multi-phase controlled atmosphere systems that avoid shackling conscious birds represent a welfare improvement that is commercially proven. At the scale of 70+ billion birds annually, improvements to slaughter methods affect more animals than almost any other intervention available. Regulatory standards requiring effective stunning and independent monitoring of stunning efficacy are essential.