Stunning method at slaughter is one of the most significant welfare determinants for farmed chickens. Controlled atmosphere stunning systems are transforming welfare outcomes compared to traditional water bath electrical stunning.
The chicken slaughter welfare case illustrates how technology can deliver substantial improvements to welfare outcomes at scale. The difference between water bath electrical stunning - with its conscious shackling, inversion stress, and missed-stun risks - and gas-based controlled atmosphere systems represents a genuine step change in the experience of hundreds of millions of animals annually. The barriers to CAS adoption are primarily economic rather than technical; the technology works, the welfare evidence is clear, and several major retailers and food companies have established procurement policies requiring CAS. Regulatory requirements, rather than voluntary adoption, would be the most effective mechanism for achieving universal implementation.