So, I'm not asking you to see humans and animals on the same level but why should that mean they deserve to die or be tortured in other ways?
Again, what about deliberately torturing a sentient being is humane?
Ok, so, they can't speak our language but that doesn't mean they don't have a voice and aren't aware, does it? They can very clearly show that they don't want to die. In the slaughterhouse, they avoid the blades and guns but are trapped by the slaughterers so that they can kill them. They scream in pain. Believe me, I've heard it in person. They show fear and that they don't want to die in other ways like dodging things and shaking, just like we do.
Again, how would you feel if this was you being treated as nothing more than an object and going through the slaughterhouse?