The SID Sheep Production Handbook states that a key limiting factor in genetic improvement is "accuracy of selection". In other words, to make the most improvement in our flocks, we have to accurately assess the impacts our sires (and dams) are having on their offspring. We need to identify superior sires as lambs and then confirm their superiority by evaluating their offspring. If they're not passing it on, it doesn't matter how good they look now or how good they looked as lambs. If you want to make the best decisions in the spring when you evaluate their offspring, you…