Different stunning methods achieve very different welfare outcomes at slaughter; understanding the evidence helps advocacy for improvements.
The welfare of animals at slaughter depends critically on stunning efficacy — how quickly and reliably animals lose consciousness before being killed. Captive bolt works well for cattle when properly maintained and applied. High CO2 gas stunning causes significant distress in pigs due to the aversive properties of the gas. Inert gas mixtures and two-phase CO2 systems offer improved welfare for pigs. Electrical stunning is advancing rapidly for fish.