I know this is a huge rabbit trail from the original question, but anyone who says that chickens won't mate with close relatives....I would never take anything else they say about chicken seriously. They apparently have no idea what they're talking about. Or, I've bred multiple lines of...what do you call smelling impaired? Not deaf, not dumb, what would that be? Anyway, my birds must all have it. I have cockerels enthusiastically mounting their mothers and sisters all the time. And the hens are fine with it.
Quote: Might be a good idea to read the study... perhaps there is more info in the study that would make sense. No reason to dismiss the entire article just because of the one comment, right?