I have 2 NH hens that are nearly 2 yrs. old. I have 1 BO rooster that is nearly 1 yr old. I finished a 5 day Corid treatment 2 days ago. I have used deep litter all winter. Yesterday I noticed that both hens have lost all feathers at top of wings. The rooster has not lost any feathers. The rooster is twice as large as the hens. I am wondering is this is d/t aggressive mating; mites/lice; or nutritional deficiency d/t Corid. Yesterday I dusted the hens and coop with DE as I will be emptying the coop soon and am worried about their condition. I began Nutridrench also. Does anyone know what is causing this? I have attached photos. Thanks.