Which is the kindest WAY to slaughter an animal for consumtion

Should this not be the NO 1 REASON FOR

cutting an animals throat or ending the animals life in another manner?

What do you think?

Carbon dioxide, does put them in a profound sleep to avoid too much of the stress hormones getting into the meat (unless we're talking about dogs, in that case, i.e. the Sumatran practices, beating them up before being slaughtered releases a lot of stress hormones which tender the meat) but not enough to kill them. Need to bleed them of, so still need the heart beating a bit when you cut the throat..

A gas chamber?