I have a flock of 11-week old chicks. Everything has gone great until this past week when I noticed a lot of feathers around the coop and run areas. I have been feeding Purina Sunfresh (available to them 24/7), all my produce scraps (excluding those that are toxic to them), and cooked egg yolks (my houseguests won't eat them so I feed them to the chicks). Could I be causing some type of deficiency in them by allowing them to have "treats" every day? Is it normal for chicks to lose feathers? Just to clarify, I am feeding Purina Start & Grow SunFresh!