New cow calf producer here. We run a feedlot/ranch and traditionally raise stocker cattle on grass then feed to finish but four years ago we started going into the cow calf business. This year we added 45 head of cows that we bought in Oklahoma and aren't very happy with how they are performing. This being said we want to start retaining heifer calves from our original cows we bought four years ago. We currently have yearling heifers that we had implanted with the synovex grass implant back in the spring. I know that ralgro is labeled to be used in heifers meant for breeding purposes but higher powered implants are not. Looking for advice on whether I can keep some of those heifers back or will I need to wait until next years calf crop to pick from.