I also feed Tucker brand feed. I fed mine the gamebird starter which had higher protein. It seemed to help my feather in a bit faster but even with that, my Buff Brahma cockerel was just as lacking in feathers at that age as yours! Your protein percentage is not the problem, it's the slow development of the breed but you might be able to speed it up a bit with even higher protein!They are on Tucker starter/grower and get whole oats on occasion along with some vegetables. They LOVE banana