I live in SE PA and am looking for a feed I can give layers as well as roosters. I would like to find a nonGMO food, but it seems all I can find is nonGMO with the added calcium for layers. We have a small flock and a self-feeder. Everyone lives together. I don't want to harm the rooster by giving him the extra calcium, and want no GMOs in my layers' feed. Any suggestions?