I don't understand the obsession with the 'pain-free' death. Surely the animal feels something in all slaughter methods, and either way it's getting killed and eaten. Frankly unless you have even been slaughtered by a Jewish butcher, how can you truly judge how much pain the animal feels?

Besides, most people have experienced a cut by a sharp edge where they don't feel pain or even realize they are bleeding for some time. This is actually a goal of Jewish and Halal butchering methods. And frankly, I'm not sure attempting to perform some 'pain-free' slaughter via impersonal machine is more humane than having another sentient being in close proximity to the animal perform the act. Modern factory slaughter is humane in the same sense a drone strike is humane.