Our feed store kept telling us to get layer pellets for our chickens since they were 16 weeks old, which I learned is not a good idea. They are 19 weeks and I suspect they will not be laying for the next 4-5 weeks. Should I switch over to grower? And what is the specific name for Grower, cause the feed store always gets confused and we end up walking out with something we don't need. Last question, since I have a rooster can I just keep them on Grower, and have a bowl of oyster shell for the hens to eat? Thanks.