Looks like your birds probably have mites - Hope you washed them with Adams Flea & Tick Shampoo.I'm brand new to chickens and have three hatchery 5-month old frizzled bantam Cochins.
Two seem to be double copy for the frizzle gene because their feathers are fragile, thin and scarce. The third has wonderful plumage. I've noticed a skin problem on all, some worse than others. Their feet and the underside of the tail of one of the sparsely feathered birds have what looks like a rash. I bathed the birds today and took pictures of the most affected bird. He was wet at the time so you can see the problem better. My thoughts lean towards some sort of folliculitis or sensitivity to the pine chip bedding. They are housed in a 10 x 6 dog exercise pen during the day that is moved around for fresh grass and a small dog ex-pen in my garage at night. I'm still waiting (and waiting and waiting) for my husband to build something that can house them outside. They don't have perches at night (waiting for the coop!) but I'll put some in today and see if that helps. The bedding is kept quite clean and is dry (no food or water in their night pen). I'm in south-central Texas, so it is hot and dry. The two most affected are housed with five other Silkie cockerels who will be going to freezer camp when I grow a backbone. The least affected, the pullet, is housed with other pullets from the same order. She is the least affected. None of the Silkies have ever shown this problem. Originally, I was intending to send all the cockerels to freezer camp, but I am really quite fond of one of the frizzle cockerels and the other is just the silliest bird and have decide that I'll keep him around as well. Since they aren't going to freezer camp, I really do need to do something about this. Thank you for any advice.
(Note: The feathers are wet from a bath.)
This bottom picture is of the underside of his tail. Again, the feathers are wet from a bath. The bird is lying on his belly with the tail pulled up so you can see the redness.
