I was just given two 9 week old Americauna hens that are in with my five year old hens. The older hens are on layer feed, and I've read that the younger ones shouldn't be eating that. Some say they will be fine, some say it causes liver damage. Should I buy grower and mix with the layer feed and offer oyster shells to the older girls? Another thing I read was to find an all purpose food (not grower, layer, etc) but I don't seem to find any of that in our area. Would appreciate any suggestions! Thanks! I have three Buff Orps, two black Australorps and now two Americauna little girls!