I've read several posts about chickens who have lost their feathers -- 3 of my 4 have completely bald backs now and the 4th one looks like she's on her way. The rooster is fine. They've been that way most of the winter -- burrrrr! I treated them several weeks in a row with DE back in January, I keep their coup clean and dry, I can't see any bugs, and the skin doesn't really look irritated.... Then I read a post that it would be a protein deficiency keeping the feathers from growing back. Could that possibly be all it is and will black sunflower seeds or a handful of cat food a day take care of it? That would be too easy! Wild pigeons and other birds mix with my chickens in their yard. Could that be a problem? They are great layers still and the eggs are yummy, but I'd hate for anyone to see the pathetic looking chickens they come from! Suggestions, anyone? Thanks.