LOL! We humans have more of an issued with chickens eating chickens than chickens do. They're a very cannibalistic species, and pretty indiscriminate when it comes to finding a good protein source. Trust me, whatever form of meat you opt to give them they will DEVOUR it, and be better for it. A molting chicken needs lots of protein and some healthy oils to get through the challenge of growing all of those feathers. My "secret formula" for them isn't Feather Fixer, which I've had only mediocre improvements with, but a combination of animal protein including animal fat(raw unless it's chicken), either black oil sunflower seeds or a wild bird seed mix with black oil sunflower seeds in it, and some fresh greens like kale or young sprouts. I've seen the most stubbornly bald birds suddenly sprout new feathers all over their bodies by feeding them this combo.
To keep the cost of the protein down, I sometimes visit the meat department at the local grocery store and seek out the markdown meat that's reached its expiration date. I've literally gotten flats of meats for a couple of bucks because it was expiration day, including grass-fed bison and beef that I would normally pay a premium for for my family. Just a thought...