I think the concept of race goes back to 19th century anthropology that tried to establish clear categories of human : negro, causasian etc. This is long discredited as such clear categories are proved to not exist in any scientific sense.
Back to the meat. Halal and Kosher both stem from the book of leviticus don't they? Making sure that animals are not diseased when they are slaughtered. So in simple terms of several thousand years ago - if it looks half dead, groggy or semi conscious then it may not be fit for human consumption.
This has been perpetuated by religions as part of the general "thou shalt or shalt not" religious laws. Power, control, us and them etc.
There is little agreement amongst muslim groups about the exact requirements I understand. Which makes food labelling a bit tricky. What is halal to one is not proper halal to another.
I was reading an article in NZ about the effects of stress on the quality of meat. A group of farmers, aided by a scientist, were researching how to manage lambs in the weeks running up to slaughter, so as to produce a tender "low stress" humane product. So the science exists to determine what is and is not stressful to animals.