Hello. My girls are about 17 weeks old (not yet laying) and I still have a bunch of medicated feed. What do you think about starting them on Layena (or some other layer feed) now and mixing it with the chick feed? Or, doing the mix maybe for the next week and then Layena exclusively? AND...if I feed Layena, do I need to give oyster shell as well? AND...if so, do I wait on the oyster shell until they begin laying? Thank you!