I have 8 chickens who are a couple of weeks apart in age. First batch of 5 is around 9 or 10 weeks old, second batch of 3 is around7 - 8 weeks old. Right now, I'm feeding them all Purina medicated chick starter that I buy at TSC. What happens when the older ones start laying? Do I keep feeding the younger ones the starter until they start laying, or do I change everyone over to laying feed? And how do I make sure they eat what they're supposed to if I have to do separate feed? They're all in the same coop/run, so separating them could prove tricky. Thanks!