Bull sale season is under way, and producers will have many opportunities to buy bulls from now through the end of May.
With all of the options - sale dates, breeders, cow families and sires - to choose from, the decision of which bull to buy may not come easily.
“The first step in bull buying is to determine your expectations of your bull,” says Carl Dahlen, North Dakota State University Extension Service beef cattle specialist. “Certainly, he needs to be fertile and get cows pregnant, but beyond that, each rancher has his or her own expectations of a bull. Some producers need a bull that will produce growthy calves that have maximum weight at the time of weaning, while some select bulls that will minimize calving problems. Still others want the highest quality carcass possible.”
However, selecting for just one trait can have consequences. For example, by continually selecting bulls for the heaviest yearling weight, producers inadvertently would increase the mature cow size in their herd if they consistently select replacement heifers from within the herd. In addition, the heaviest yearling weights may be associated with heavier birth weights, which could lead to calving difficulty.
The best way to select a bull is to decide on a combination of traits that best fits the needs of the cow herd. Once the herd’s needs are realized, the decision about which bull to purchase is much easier.
“Choosing the right bull involves both a physical evaluation of the bull and a review of the available genetic information,” says David Buchanan, an animal genetics professor in NDSU’s Animal Sciences Department. “When looking at bulls, producers need to review the structural correctness, frame size and muscling pattern, and see whether the bulls have an overall eye appeal that they want to have in their next calf crop. A breeding soundness examination is also important.”
The review of available genetic information can be difficult. Sale catalogs will list expected progeny differences (EPDs) for calving ease, birth weight, weaning weight, yearling weight, milk and scrotal circumference. In addition, EPDs are available for carcass traits including carcass weight, marbling, ribeye area and fat thickness.
“While EPDs are the best estimates we have of the genetic worth of a bull, they are often used incorrectly,” Dahlen says.
To be used appropriately, EPD values from one bull in the sale catalog need to be compared with those of another bull. A bull with a weaning weight EPD of plus-40 will not have calves that are 40 pounds heavier than the breed average. They will, however, have calves that are 40 pounds heavier than a bull with a weaning weight EPD of 0.
All EPDs published are specific to a particular breed and should be used only for comparison of animals within that breed. Also, the breed average EPDs are quite different for any individual trait.
An Angus bull that has an EPD of plus-40 for weaning weight is much different within his breed than a Shorthorn bull with an EPD of plus-40. In this example, the Angus bull would be right at the breed average of plus-40, while the Shorthorn bull would greatly exceed the 14-pound average EPD for weaning weight.
Each breed association will have its breed average EPDs for spring 2011 available on its website or through its breed representatives. A listing of the breed average EPDs for 17 breeds reported by the U.S. Department of Agriculture is available at http://www.bifconference.com/bif2010/documents/10_kuehn_thallman.pdf.