I want to switch my Cornish X chicks over to unmedicated feed for the last 30 days and I can't find it what do I do? A guy at one of the feed stores sold us a bag of Layena and said that would fatten them up but when we read on that when we got home it said no chicks under 18 weeks should be on that. So for now we are keeping them on the medicated chick crumbles.