What’s the story with shekhita and it being humane? Is it or isn’t it? Is there something in the Tora that says we shouldn’t torture animals (tzar ba’alei Hayyim)?
I do not believe that shechitah is any less humane that other methods of killing. When performed correctly, ritual slaughter is painless to the animal, because the immediate severance of both the blood and oxygen supply to the brain causes the animal to quickly lose consciousness and all sensation. Anemia of the brain occurs within seconds.
You are right in that the Torah forbids torturing animals. Yet, although there is certainly some pain (even instantaneous) caused in shechitah, this is permitted, for it not torture for the sake of cruelty or sport, but for the sake of human consumption.