Sir, I am horrified to read your news article discussing the CO2 shortage crisis.

Horrified, because the use of carbon dioxide gas is highly aversive to pigs: this appalling stunning method causes severe suffering and distress for the animals.

The real crisis is the fact that we are still slaughtering over 50% of our pigs using carbon dioxide at all.

Individuals in this article claim that this shortage of CO2 is a risk to pig welfare. Here in the UK, many piglets are born to mothers incarcerated in farrowing crates, unable to turn around for weeks. Most of our pigs are reared on factory farms, and often tail-docked, which is illegal, painful and would be an unnecessary practice, should our pigs be given better conditions including more space while they are reared. Following this, half of our pigs are slaughtered with high levels of CO2, causing severe distress just before their deaths. There are more humane ways to rear and slaughter our pigs, if only more producers would do so.

It’s an absolute scandal that, over 25 years since Bristol University scientists condemned this method as causing ‘severe respiratory distress’, over half of UK pigs are killed using CO2. This archaic method of slaughter must be banned and anything that pushes the industry away from this inhumane slaughter method is welcome.

Philip Lymbery, CEO, Compassion in World Farming