I have 4 chickens (black sex links and ideals) and every single one of them has lost their fluff feathers (all feathers that cover their rear ends) and their saddle feathers (the feathers next to their tail). It has been this way for several months and they show no signs of feathers coming in. It looks terrible. I have them on a high protein egg layer feed which is supposed to help them regain their feathers. Is this molting or could there be something else causing this? Listing all possibilities would help me gain more knowledge as my resources are greatly lacking in information. Any feedback is greatly appreciated.