As a meat eater, I don't think there are too many serious challenges outside of religious beliefs to the ethical arguments for veganism. Mammals at least are clearly as sentient about survival and their kin as we are. But that doesn't mean we can't accept that their suffering is worth it for our gustatory pleasure. I could accept a world where I simply have to pay more for meat to spare the horrors of factory farming, but I have no personal problem with humane-intentioned husbandry and slaughter.