Bull Selection Is Foundation For A Profitable Herd
Bull selection is the foundation for building a profitable beef herd. In
most commercial herds, bulls are purchased and replacement heifers are selected from within the herd. The sire and
dam each contribute 50 percent to the genetic make-up of each calf. Half of a dam's contribution to her calf comes
from her sire and a fourth comes from her dam's sire. Thus, 87.5 percent of a calf's genetic material comes from
three bulls that were brought into the herd. Sire selection is the major tool available to producers for changing
the genetic potential of a herd.
Sire selection can and should be more accurate today than ever before. Beef breed
associations have developed programs that use performance information on a bull's relatives in addition to his own
records to produce Expected Progeny Differences (EPDs). This article discusses methods of using these data and
considerations involved in selecting bulls to be used in natural service.
There are two basic ways to bring about genetic improvement in a commercial herd
-- crossbreeding and selection. The purpose of crossbreeding is to produce heterosis (hybrid vigor). A good
crossbreeding program is important in improving reproductive traits and production traits like rate of gain.
Selection of superior breeding stock is most effective in changing production traits and carcass traits. A good
breeding program for a commercial herd will include both a designed crossbreeding system and selection of superior
bulls within the chosen breed or breeds.
The crossbreeding system used will affect the type of bull that is needed. In a
rotational system, heifer calves are kept for replacements. General-purpose breeds of comparable size are normally
used. Disposition, calving ease, moderate size, fertility, maternal ability and gain are all important criteria for
bull selection. In a terminal crossbreeding system, bulls from larger, growth breeds are typically used on smaller
cows, and all calves are sold as market animals. Growth and carcass traits are very important, while maternal
traits are not important since no heifers are kept for replacements. The crossbreeding system should be planned
before individual bulls are selected.
With a planned crossbreeding system established, the next step is to critically
evaluate the cow herd. Look at the cows in terms of how they fit available resources such as feed, labor,
facilities and environment. Look at how calves fit market demand. Determine the weak points and strong points of
the herd. This will help in describing the type of bull that is needed. It is almost impossible to find a bull that
is superior in every trait. The goal is to find a bull with an acceptable combination of traits that complements
the strengths and weaknesses of the cow herd.
After a crossbreeding system has been established and the type of bull has been
determined, it is time to decide where to buy. Only consider reputable sources that can provide complete
performance records. Performance records and pedigrees are only as good as the integrity of the breeder. Sellers
should make results of breeding soundness examinations available and guarantee the quality and fertility of bulls.
Herds that are actively involved in their breed association performance program are excellent sources for
Bulls from these herds can be bought privately, at production sales, at central test
station sales or at consignment sales.
Whether bulls are purchased at auction or privately, be sure the information needed to
make a wise decision is provided. If it is not presented, ask for it. If performance information is not available,
look elsewhere for bulls.
Growth and Calving-Ease
Birth, weaning and yearling weights are normally used to evaluate breeding
animals. Actual or adjusted weights may help in making comparisons between bulls in the same contemporary group (a
group of animals from the same herd, year and season raised together under the same conditions). Since
environmental factors like feed and weather affect weights, actual or adjusted weight, can be misleading if bulls
come from different contemporary groups. Within a herd, weight ratios help account for some of the environmental
differences between contemporary groups. A ratio of 100 means a bull's weight was average in his contemporary
group. A ratio of 110 means a bull's weight was 10 percent heavier than average. Ratios can also be misleading if
bulls come from different herds. EPDs, on the other hand, are calculated across herds. A bull's EPD for a trait
many times is a more accurate estimate of his genetic worth than his weight, adjusted weight or ratio. EPDs not
only account for contemporary group and herd differences, they also include information on a bull's relatives, as
well as his individual performance.