Stunning of pigs before slaughter is legally required in the UK and EU, but the effectiveness and welfare impacts of electrical and CO2 stunning methods vary significantly.
Pig stunning welfare at slaughter is critical because it represents the final experience of an animal's life. Poorly applied electrical stunning or CO2 immersion at suboptimal concentrations means animals experience pain, panic or distress in their final conscious moments. The welfare standards for stunning specify electrode placement, minimum current and duration for electrical systems, and CO2 concentration thresholds - but variation in equipment condition, operator training and monitoring consistency means these standards are not uniformly achieved. Post-stunning monitoring to ensure unconsciousness before sticking is a welfare requirement that needs rigorous enforcement and genuine commitment from processing facilities.