Selecting a herd sire is one of the most important decisions a cowcalf producer makes. A herd bull contributes half the genetic makeup of his calves and plays an essential role in herd genetic improvement. The herd bull is the most important individual in a breeding herd. A cow or heifer typically produces one calf per year, while a mature herd bull may sire 25 or more calves per year. Thus, a herd sire may contribute more to the genetic makeup of the herd in one breeding season than a cow contributes in her lifetime. Selecting genetically superior bulls is the quickest path to herd genetic improvement. The value of a bull above slaughter value is his ability to sire live calves and transmit superior genetics to the herd.