My chicks are only just over a week now so i hope that this stays true . . . we ran low on medicated started and called the local feed store and was told that the chicks can/should stay on starter til tehy are 8 weeks old and their thoughts are that the chicks shoudl not be on medicated feed unless they are sick, which actually makes sence to me. I have a friend who lives near by who has older ladies and say that she goes to that same feed store and follows their advice. So I have switched my babies to non medicated (about 4 -5 days ago) and they are doing fine.