Since there has been not response from our halal/kosher endorsing friend, I shall make this statement.
I find the argument that halal/kosher methods of slaughter are more humane than rendering the animal unconscious prior to slaughter to be utterly puerile. It is an obvious nonsense perpetrated by people who have a vested interest in maintaining their religious customs at the expense of animal welfare.
It is an absurdity to suggest that an unconscious animal 'feels' more pain than its fully conscious, religiously slaughtered, counterpart.
Kosher/halal slaughter is an unnecessary cruelty inflicted upon animals because of religious dogma. It has no place in a supposedly civilised society where it is recognised that, while we consume animal meat, we also owe that sentient creature a duty of care. And that duty of care includes – right up to the point of its death – not causing the animal unnecessary suffering.
I believe that the kosher/halal method of slaughter does not conform to that ideal and does indeed cause unnecessary suffering.