Despite being only 2% digestible in their raw form.. feathers are made from 90% protein and it's amino acids. Diet has a definite effect on feather quality and protein content is not the only factor.. but will not make angry skin. The average 16% protein in most layer feeds is considered the...
More like a red/gold sex link type (possibly an Orpington).. Angry red skin looks like possible parasites.. Consider treating with a permethrin based product (no egg withdrawal required) found on the equine isle (horse fly spray) follow up according to directions, or other effective treatment...