I have 12 grown chickens (some buff orps, some light brahmas) in our chicken coop. Noticed that their chicken feathers were being plucked from some (not all) of their breasts and on some of their tushies. I realized that they were deficient in there food and have started taking measures on correcting that, but a couple of the hen have sores and a green patch that seems to be getting bigger on their breast. I am wondering if anyone has any idea what it could be and if there is anything I can do? I am new to the site.