The method used to render chickens unconscious before slaughter has a profound effect on welfare at the most critical moment — yet standards vary enormously across the industry.
The first moment of the slaughter process — the live bird being removed from transport crates, shackled upside down, and moved to the stun bath — is one of the most stressful episodes in a commercially farmed chicken's life. Pre-stun shocks from inadequate electrode placement cause pain before unconsciousness. Shackling induces wing fractures and extreme distress. Controlled atmosphere systems that put birds to sleep in their transport module entirely avoid live handling and represent a transformative welfare improvement. The cost differential is modest; the welfare benefit is profound.