This is perfectly well true, but I'm not interested in addressing this because I have never known this to be anyone's sufficient objection to eating meat.
Would you eat a well-treated chicken? How about a deer instantly killed by a Predator drone equipped to vaporize its brain faster than neurons react?
I know this comment has already been objected to, but I'll pile on anyway. Torture is my objection to eating dairy and eggs. Stop the torture, and I will switch back to vegetarianism over veganism. I am currently willing to buy dairy, at least, from "humanely raised" farms (though I never see it in stores, it does exist).
http://www.smbc-comics.com/index.php?db=comics&id=2393#comic