SG_USA_January_2021

By Emily Stribling, Contributing Writer

Bull Selection Making an Informed Investment in Your Herd's Future

S pring breeding season is right around the corner and it’s time to start thinking about future herd sires. When it comes to the direction of your operation, bull selection isn’t something to be taken lightly. “Buying a bull is an investment,” says Matt Spangler, Ph.D., Extension beef genetics specialist, University of Nebraska-Lincoln. “You’re investing in genetics that will impact your herd for years.” Expected progeny differences (EPDs) are a great starting point for evaluating potential sires. EPDs are a prediction of how an individual animal’s future prog- eny are expected to perform relative to those of other animals within the breed. They are expressed in the units of the trait being evaluated (plus or minus) and are meant to compare the potential of one animal to another. A more recent advancement in the industry is the introduction of genomic- enhanced EPDs (GE-EPDs). By includ- ing DNA into the breed’s EPD calcula- tions, estimates are more accurate than pedigree and performance prediction alone. This is especially advantageous in young, unproven sires that have yet to produce any offspring, giving buyers greater confidence in the future perfor-

mance of their selection. With so many EPD traits to consider, it can be difficult to know what to focus on most. Know- ing where to start is key to making the right buying decisions. As with any major decision, it’s important to determine your operation’s goals and marketing endpoints. Are you producing and developing females as replacements? Are calves sold at wean- ing or being retained through the feed- yard? Endpoint goals greatly impact what traits to focus on in the selection process. For a typical terminal opera- tion, the main focus is on end weights as you will be paid for pounds of calf at weaning. When retaining through the feedyard, however, traits such as year- ling weight, ribeye area and marbling begin to come into play. When breeding with a replacement mindset, “the focus is on traits for revenue at the point of sale – reproductive stayability, milk [maternal EPDs], mature cow weight, etc.,” Spangler says. Unique to Santa Gertrudis are two more EPD traits to consider for a replacement system – Heifer Pregnancy and Breed Back EPDs, which measure the probability of a heifer getting preg- nant as a yearling and the probability of a 2-year-old being pregnant given she

was listed as pregnant as a yearling, respectively. Accounting for these traits is especially important. “The Santa Gertrudis breed is known for carcass traits, [and] Heifer Pregnancy and Breed Back EPDs are a way to quantify/prove fertility within the breed,” says Webb Fields, Santa Gertrudis Breeders Inter- national executive director. When it comes time to purchase bulls for your operation, preparation is key. “A live calf on the ground is the determining factor between being prof- itable and not,” Fields adds. Regardless of marketing endpoint, it’s also important to consider the current state of the cow herd. Know- ing the average cow age, pregnancy rates, stayability and calf end weights will further guide your focus in the right direction and help determine how much change is needed to reach your goals. With a clear direction in mind you can begin researching upcoming sales, obtaining catalogs/information and sorting through bulls on paper. Fields suggests getting as much knowledge ahead of time as possible. “Know breed

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