Go buy a bag of meatbird crumbles or gamebird crumbles and mix it in. That should bring you up to a decent protein percentage. In future, if you feed layer, don't give them corn. If you really want to mix corn, buy a higher percentage protein feed like meatbird.I just bought a brand new bag and mixed it all in together should I go buy another bag of layer crumbles? It’s just the one hen picking feathers from that one certain hen. The others aren’t doing it.
Some hens do better than others on low protein, the one picking may just be the most susceptible. The hen being picked on is just an easy target because she's low on the pecking order currently.