I think Curtis nailed it this time around.
I don’t see that as a barrier. Plenty of “protected groups” (blacks, Asians) are plenty racist or homophobic. The enforcement arm of political correctness is almost always wielded by one group of whites against another another group of whites - what protected groups believe is not an issue, and not up for debate.
You are right, of course, if we are talking about laws and the way they are enforced, but I was really, in a rather flippant way, attempting to say something about the ethics of the situation, not the legal possibilities. Animals are not the moral equals of human beings, because they cannot understand morality or in any way treat humans (or other animals, come to that) according to any sort of ethical norms. That is not the same with any sort of human group (except, perhaps, the very seriously mentally handicapped). Although some humans may be racists, and even proud of being racists, they have the capacity to learn better. Animals do not.
Speciesism is already unacceptable to fruitcakes and nuts.
However until animals start being kinder to one another, or become significantly less delicious (to either each other or to us), I don’t see much more beyond kinder husbandry for the masses.
And if the last pregnant cow on earth is between a human family and starvation, I’m betting on the humans…