“Because pigs are highly intelligent and easily distressed, group gassing is touted as the most ‘humane’ method of rendering them unconscious before slaughter. Most pigs are now killed this way. But the Australian meat industry standard requires a CO2 concentration at least four times higher than what is scientifically known to avoid distress.
CO2 is a cheap but aversive gas. When exposed to high concentrations of CO2, most pigs panic and have a violent reaction — potentially accompanied by pain. If the CO2 concentration is less than 20%, pigs will generally not detect the gas. Yet the Australian meat industry standard is set between 80 – 100%. At this level the kill line moves more quickly — but most pigs are going to their deaths highly distressed or in a state of terror.
Every abattoir is under pressure to kill as many animals as possible in the shortest time. This financial imperative is reflected in the industry standard that puts efficiency ahead of animal welfare. Perhaps the most alarming consequence of this cruel standard is that even if an Australian abattoir wanted to gas pigs in accordance with what is scientifically proven to minimize suffering – currently they risk failing audits and losing their license.”