I give my chickens table scraps to the horror of my mother and disappointment of my dogs. I don't give them chicken or pork - chicken because that's creepy and pork because I have a Muslim friend who gets eggs from me sometimes. (I don't know that it's a no-no, but just in case. Plus who ever has leftover pork?
) I don't know that I'd want livestock feed that had animal by-products in it though. I think the government has cracked down on it since it's a vector for some really nasty diseases if improperly rendered.