I have 12 chickens that are 19 weeks old. They haven't started laying yet but that's right around the corner I'm thinking. I bought layer feed about a week ago in anticipation and I noticed on the bag it tells me not to feed it to chickens under 20 weeks old and said it could be harmful. So I went back to my regular Start n Grow I think it's called, red bags. I have placed two shipments of chicks, 15 more are arriving and I'm also inheriting some from a friend getting out of the hobby. One order is September 6th and the next is on October 17th. Will I need to segregate my chickens? Is layer feed completely necessary in the winter months? Is there some kind of alternative that can be used to feed birds of all ages? I prefer to use medicated feed on young chickens. Thank you.