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Assuring Bull Performance For The Spring Breeding Season
BRYAN KUTZ
FAYETTEVILLE, ARK.
Breeding season is just around the corner for producers whose cows calved in the spring, and it is never too late to start planning. Improvement of next year’s calf crop is dependent upon the breeding decisions you are about to make. Males account for approximately 90 percent of the gene pool, contributing more to the genetic makeup of a herd in one breeding season than a cow contributes in her lifetime. Selecting genetically superior sires is the fastest approach to herd improvement and ultimately bottom line profitability.
For those of you who already a have a bull in place, remember that breeding success depends on the reproductive health of both the cow and the bull. However, because a bull is expected to service various numbers of cows, the potential fertility of the bull is much more important than determining the fertility of any individual cow. It is consequently essential to evaluate bulls every year before breeding starts because the fertility of a bull can vary from year to year. The breeding soundness exam should be performed 30 to 60 days before the start of breeding season. It is important to allow sufficient time to replace questionable bulls. This time allotment will also allow for enough time for stressed animals to recover and be tested again before the beginning of the breeding season.
Not every bull will fit your production scenario. Resources and goals are different for each cow-calf operation. Nonetheless, sire selection should target an acceptable combination of traits that complement the strengths and weaknesses of the cow herd and match markets.
Ask questions that pertain to your particular production situation. What are your target markets? Are you selling all calves at weaning? If so, what color does that market value the most? Are you planning to background your calves and send them through the feedlot? Are you going to retain replacement heifers? Are you breeding both heifers and cows? What are your available labor and forage resources?
Answers to these questions will aid you in determining the selection efforts you may want to apply towards economically important traits such as growth, carcass traits and possible maternal performance. Feet and leg soundness, libido, disposition, scrotal size, sheath, frame size, composition, breed type and horn presence or absence are also important traits for consideration. While one may apply more pressure on one or two traits, remember to strike a balance among various traits and avoid extremes. Base the type of sire selected on the purpose of your breeding plan.
Along with adept visual appraisal of an animal, the use of genetic selection with expected progeny differences (EPD) can be an extremely valuable tool. EPD’s provide predictions of the expected performance of the calves sired by a bull compared to the expected performance of calves sired by another bull. EPD’s are the best predictors of the genetic performance of an individual animal, and they are available for a growing number of economically relevant traits. Breeds are different and make available a wide variety of EPD’s; however, most breeds have basic EPD’s, such as birth weight, weaning weight, yearling weight and milk. A large number of breeds have implemented the use of selection indices. These are based on multiple traits weighted for economic importance, heritability and genetic associations among traits. A selection index may provide a balanced selection approach when selecting for more than one trait at a time.
Beef cattle selection should be based on many factors. The knowledge gathered from your production needs and concerns is invaluable in your sire selection endeavor. The more information used in this process, the fewer surprises you will have for generations to come. It is important to use both performance information and visual appraisal in choosing a sire that suits you and your production goals. They should complement each other.
A balanced approach to sire selection focusing on multiple economically important traits can go a long way towards herd genetic improvement. Nonetheless, without a proper breeding soundness exam (BSE), these decisions may not matter. Remember that a bull is only as good as his semen. A cow is responsible for half the genetic material in only one calf each year, while the bull is responsible for half the genetic material in 20 to 50 calves. The bull’s ability to locate cows in estrus and breed them is clearly vital to any successful breeding program. ∆
BRYAN R. KUTZ: Instructor/Youth Specialist, University of Arkansas
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