JoeR - 5/25/2017 08:11 I have 2 groups of cows. One group gets implanted and the other does not. Using black/red angus bulls on one group, hereford bull on the other. The groups of calves were sold within 2 weeks of each other. Calved the same time, weaned same time, both were on creep (one group didn't go through as much as the other), and both had very similar rations after weaning. Through the ring, they were just about identical average weights. 'Here' the sale bill is usually loaded with NI calves. FWIW I think that your rate of gain difference would be more attributed to the weather, the cows, and what they were eating, not implants.