Beef breed associations have developed programs that use performance information on a calf's relatives in addition to its own record to estimate its breeding value for different traits. This fact sheet discusses methods of using this data and considerations involved in selecting bulls to be used in natural service. Selecting Bulls When selecting a bull for natural service, first the buyer must know the kind of bull that will meet the breeding program's needs. The kind of bull needed will depend upon available resources, such as feed, labor, facilities, cow herd, environment, market demand, and the breeding plan followed. The goal is to find a complete, functional bull capable of siring calves that will contribute to herd profitability.
Producers can no longer afford to try to maximize any single trait.
The effect of the breeding plan can be illustrated by comparing rotational and terminal crossbreeding systems. In rotational systems, general-purpose breeds of comparable size are usually used and maternal traits must be considered since heifer calves will be kept for replacements. On the other hand, a bull from a large, growth breed is used on smaller-sized cows in terminal crossbreeding systems. Maternal traits of the terminal sire would not be important in this case since heifers are not retained as replacements. Once the type of bull needed has been determined, the second step in sire selection is to decide where to buy.