okay, chicken experts!! I have three 20 week old bantam cochins, 1 13 week old EE, and six 9week old chickens. I believe we have removed all of the roos, time will tell. I am currently feeding them starter feed with grit and de mixed in. One of my banties has laid 2 eggs, and I would like to put them on layer feed. Is it safe to feed it to everyone? How do I feed oyster shell to just the layers?? I don't want the young ones to damage their kidneys. What to do??