Need some help on losing feathers

[Wingwalker]

I have ten RR hens and two rosters. All but one of the hens has lost the feathers around the tail area, both top and bottom. I can't say mostly on top or bottom about the same. The areas are very red. Even the dominate roster has a bald spot on his bottom.
Not knowing what to do I have sprayed all of them with Blue Kote.
Can anyone tell me what might be the cause and a solution?

 

[dawg53]

There could possibly be several things going on; the roosters are overmating your hens causing feather loss, lice/mites, or a feather picker.
It's normally recommended 1 rooster per 10 hens. Visually inspect your birds for lice/mites. If they have them, treat with sevin dust and re-treat them again in 7 days...same with coop and nests. If it's a feather picker, apply Vick's Vapor Rub or Rooster Booster Black Salve to the rear tail feathers of your birds

 

[nurse_turtle]

I suspect both over-mating behavior and lice. Search the bases of the feathers around the vent area and look for clusters of white eggs and tiny critters crawling about. If one chicken has it, they all have it.

 

[Wingwalker]

Thanks for the reply. I will go with the seven dust (can't hurt even if its wrong) and I think it is time to put a roaster in the pot.
Thanks again,