Sometimes it's not the percentage of protein that is the issue, it's the type of protein. Chickens need animal protein. When they don't get the right type in their feed, they'll take it where they can, and that can mean plucking each other's feathers.
What I do (and others as well) if I can't find feed that has animal protein in it, is add some dry cat food to my birds ration. It's not an ideal solution, but better than having them picking each other.
Try it.
What I do (and others as well) if I can't find feed that has animal protein in it, is add some dry cat food to my birds ration. It's not an ideal solution, but better than having them picking each other.
Try it.