Well we can go on and on about this can't we?
Anyway whatever you say will not alter my Respect for animals and my disgust for how they are treated.
My point about the slaves was that there were people who thought about slaves just like you are thinking about animals. But we all know that they were proven wrong.
Also simply without much elaboration on anything about animals having "rights" or not or if they are "conscious" or not or even if they have "free will" or not, how about if we all just start by SIMPLY RESPECTING ALL LIVING BEINGS. Adjusting our thoughts slightly towards respect will change a huge lot and go a long way.
I can respect my animals very much, but do not confuse it with animal having rights, because it's nonsense. I can respect my chickens, treat them well and then eat them, nothing wrong with that.