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Selecting herd sires doesn’t have to be overwhelming

by Wyoming Livestock Roundup

Published on Feb. 1, 2020

With bull sale season fast approaching, producers will be receiving a plethora of bull sale catalogs in the mail. As many are aware, it doesn’t take long before becoming swamped in the information provided in these catalogs. However, University of Nebraska-Lincoln (UNL) Beef Extension Specialist Dr. Matt Spangler says thumbing through bull sale catalogs and selecting herd bulls doesn’t have to be ovewhelming.

            “There is a lot of information in sale catalogs and it can be overwhelming to the point where I fear a lot of producers just cast the catalog aside and physically go out to inspect the bulls,” Spangler explains. “Certainly there is merit in ensuring bulls are sound and temperament is appropriate, but outside of that, if they want to choose a bull that is going to add profit in their offspring, they are going to need to focus on bull expected progeny differences (EPDs) and economic indexes.”

EPDs versus economic indexes

            Spangler explains EPDs include information from a bull’s own phenotypic records, such as his weaning weight, yearling weight, ultrasound data and DNA information, if he has been genomically tested. 

            “A lot of information in EPDs is also from the bull’s relatives, including his parents, half siblings, full siblings, grandparents, etc.,” he says. “EPDs are really the best tool we have at predicting the genetic merit of the individual as a sire.” 

            Spangler notes there are numerous EPDs, however a few are more useful than others.

            “Perhaps the most commonly used EPD is birthweight EPD,” states Spangler. “If I had my choice, the birthweight EPD wouldn’t be published, and the reason I say this is because we have calving ease or calving ease direct EPDs which are more useful.” 

            Spangler explains calving ease and calving ease direct EPDs are a direct measure of how easily a bull’s calves will be born when bred to heifers, which is economically important to producers. 

            “How big calves are obviously influences this, but birthweight itself is not an economically relevant trait, so I encourage producers who are breeding bulls to heifers to look at calving ease direct,” says Spangler.

            Spangler also points out birthweight is included in calving ease direct, so if they are using both EPDs simultaneously, they are actually double counting the importance of birthweight. 

            “If producers are retaining replacement females, they should also pay attention to calving ease maternal,” Spangler explains. “This is how easily a bull’s daughters will give birth their first time around, which is obviously extremely important.” 

            He continues, “Stayability or sustained cow fertility is a measure of the length of productive life of a female, which is important. Producers in limited environments should also pay attention to the mature cow weight EPD and milk EPDs and try to keep them more moderate. In some cases below breed average may not be a bad thing as it is a means of keeping input costs low.” 

            The last EPDs Spangler encourages producers to be aware of are post-weaning gain and carcass traits, even if they sell their calves at weaning.

            “Even if producers sell their calves at weaning, somebody is going to feed them out, so post-weaning gain and carcass traits are important for building demand for our calves,” he says. 

            Spangler explains economic indexes are an index of EPDs that are weighted based on the relative economic importance of the particular trait.  

            Spangler notes he believes economic indexes, when used correctly, can simplify a producers decision of which bulls to put on their buying list as indexes rank bulls based on their genetic potential to change net profit. 

Setting parameters

            Spangler notes setting parameters around which EPDs and indexes producers should pay attention to when selecting for sires is the most complicated part of buying bulls.

            “I truly believe it starts with asking three questions,” he explains. “The first question a producer should ask themself is what their breeding objectives is.” 

            He says an easy way to clearly define a breeding objective is to write it down.

            “What I mean by breeding objective is the producer needs to identify whether they plan on buying replacement females or producing them themselves, when and how they plan to market their calves and resources that may be limited on their ranch, such as forage or labor,” Spangler explains. 

            The second thing producers need to identify, according to Spangler, is what traits directly impact the profitability of their operation. 

            “Writing down a breeding objective helps to identify the traits that are really impactful to the net profit of their enterprise, which narrows down the list of traits they need to focus on,” he says. 

            Spangler continues, “Within this, it is also helpful to have some sort of benchmark. Producers should think about the history of how their calves weighed at sale time or if they retain ownership, how their calves perform post-weaning and what their pregnancy rates are like.” 

            Spangler says the third question producers need to ask is if there are any environmental constraints that dictate the level of performance that is acceptable for a given trait on their operatio.


            “There is no doubt for a self-replacing herd fertility, sustained cow fertility in particular, is an economic driver,” states Spangler. “When well done, crossbreeding and heterosis has the most impact on these fertility traits.” 

            Spangler notes research done by the U.S. Meat Animal Research Center (MARC) suggests the benefit of heterosis compared to purebreds provides an additional 1.3 years to a cow’s productive life, which is nearly 600 pounds of cumulative weaning weight in her lifetime.

            “Crossbreeding systems don’t need to be complex,” Spangler says. “Oftentimes, people think of crossbreeding as the complex three-breed rotational system, but it can be a simple as buying composite bulls to utilize.”

            “There are multiple breed associations who record EPDs and economic indexes for composite bulls, so there is no sacrifice of information,” he continues. “This can be a really easy way to interject some degree of heterosis or hybrid vigor, especially for producers who need an easier management plan to implement.” 

            Spangler says a few of the most important things producers need to consider when implementing crossbreeding are to not get caught up in the ‘breed of the month.’ Instead, they need to pick a plan and stick with it. He also notes producers need to think about crossbreeding in the context of its ability to extend the length of their herd’s productive life and to remember crossbreeding is a long-term decision. 

Choosing a seedstock producer

            “There are a lot of bull sales across the country, so as a consequence, there are a lot of seedstock producers to choose from,” says Spangler. “I think it is important, as with any commerce, to do business with people they trust. Producers should really do business with somebody who stands behind their product and is honest.” 

            Spangler also notes producers should choose seedstock suppliers with breeds that fit their breeding objectives and who have bulls that excel in the traits that are economically relevant to their operation. 

            Information from this article was compiled from UNL’s BeefWatch podcast and Bull Selection Principle – Be an Educated Consumer, an article written by Dr. Matt Spangler found at

            Hannah Bugas is the assistant editor for the Wyoming Livestock Roundup. Send comments on this article to

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