The Simmenthal website probably has a somewhere tha they define what percentages are required to be purebredcolleen":21izyx2b said:We never planned on doing the registered cattle thing, we just wanted a good bull. We ended up getting some quality Simbrah cows too and now have all registered Simbrahs except for 2 old cows. So far we are very pleased! Hold up really well in our southeast Texas climate. Never had seen one that had purebred on the papers.