I have about 35 mixed chickens. Just a back yard flock. I buy for the appearance rather than the breed. I love to collect the odd ball chickens. They free range in my backyard. They get leftover vegetable scraps out of my compost pile (more often than I would like them to). I feed them purina egg layer with oyster shells and sometimes we mix in a little corn/wheat scratch. A few months ago I had a chicken get attacked by the neighbors dog. I never thought she would make it. Her flesh and waddle were actually ripped away from her beak and her tongue was hanging out the bottom of her mouth. She also had lost a lot of feather. Tons were missing. After weeks of intensive care, she was able to eat on her own again and eventually walk. But what I've noticed about her is that all she f the feathers she has refrían are white. All of them. She was a full grown bird when I bought her. She was bought from a licensed and registered farm. She had not a single white feather on her before the incident. Also, I have another bird, a male, that was bought at a few weeks. They were off spring from a reputable breeder and bought for a pretty penny. It as he has aged, I've noticed white feathers where there shouldn't be. Am I feeding them something wrong? Is it a vitamin deficiency? It's only these two birds, the other ones seem fine and are the proper colors.