In concentrated carbon dioxide, pigs will panic, try desperately try to escape and gasp, before falling down and losing consciousness up to a minute later and possibly longer,
LUCY HOOKER: ‘The animal welfare campaigners, Compassion in World Farming, say using gas to make pigs unconscious is a “horrible death”. “In concentrated carbon dioxide, pigs will panic, try desperately try to escape and gasp, before falling down and losing consciousness up to a minute later [according to some sources] and possibly longer,” said Philip Brook of CIWF. The CO2 method does not meet the definition of humane slaughter, he argues, since the stunning does not take place instantly, and CIWF is calling for the government to ban this method within five years… Pigs are stunned using a 70% to 90% carbon dioxide concentrate. They are typically loaded in groups of about half a dozen onto something like a paternoster lift, which lowers them gradually into ever higher concentrations of the gas.
Once the animals have been stunned, they must be bled within 15 seconds to avoid the risk of them regaining consciousness. Using an electric stun-gun, a method still used in some abattoirs, is instantaneous. However, it requires pigs to be separated from the rest of the group. As highly social animals, this causes significant distress, according to the Humane Slaughter Association (HSA). There is also a risk that the animals will not be properly stunned due to human error. Abattoirs effectively face a choice between causing short-term physical distress, or social distress over a longer period of time… European and UK law stipulate that animals must be effectively stunned before slaughter, apart from exceptions for some religious circumstances’. SOURCE…