Yes. Any species likely to be available.My general question is if it’s okay to feed chickens meat and if so what kinds? ...What is okay and not okay in terms of meat?
Ever since the mad cow era, I avoid feeding a species to itself even though I don't think anything like that is in chickens and chickens would happily eat each other if they could.
That assumes you meant mammals, birds, and fish. If you meant more; I don't feed mine earth worms or snails because of the specific parasites common in them. If I ever get the opportunity to let mine free range, I'm not going to worry about them but until then, they don't need them. I don't feed mealworms because of the high fat and low quality of the protein combined with other treat options being a lot easier.
Not ok: much fat, salt, or sugar.