Waterbath electrical stunning is the dominant method used to render poultry unconscious before slaughter, but its reliability, welfare implications, and the conditions under which it fails are important considerations for poultry welfare policy.
Waterbath stunning is a welfare-compromised system that has persisted due to its low cost and compatibility with high-throughput processing rather than its welfare performance. The shackling of live birds causes measurable pain through joint stress and fear responses; the conveyor approach to the waterbath creates additional stress through noise, inverted positioning, and the novel environment. Birds that miss the stun — an occurrence that audits suggest is not uncommon — are fully conscious at neck cutting. Controlled atmosphere systems avoid shackling stress and the risk of stun failure, but require capital investment. The welfare case for transition to gas stunning is strong; the barriers are economic and the pace of regulatory change is inadequate relative to the scale of suffering in the current system.