I have 26 layers and 21 broilers running around on a quarter of an acre.

I have a problem with one of the broilers that I kept over from the last batch to try breeding from her. She's a Ross bird - a large, heavy, white feathered pullet, weighing probably around ten pounds at eighteen weeks. I've noticed that she has pink to red skin around her back end where the feathers are sparse near the vent. Why should this be?

She's too heavy to roost, so she sleeps and sits in the litterin the house. Could it be inflamation from ammonia, or is there a type of mite that would cause this? Her comb and wattles are bright red and she layed her first egg yesterday.