Is it OK to change what you feed your chicks? Mine have been eating (for almost six weeks now, since I got them), Purina Mills Start & Grow medicated feed, containing Amprolium. Blue Seal Feeds chick starter contains the same medication. Is it all right to change them? I can get the Blue Seal up in NH for much less than the Purina down here (haven't looked for the Purina up there yet). Also, what is the difference between crumbles and mash? I think I'm feeding them crumbles, it's clumped together a big larger than what I would consider a 'mash'.