UW Assistant Professor discusses balancing beef genetics during WSGA convention
During the Wyoming Stock Growers Association 2025 Winter Roundup Convention and Trade Show, held Dec. 8-10 at the Ramkota Hotel and Conference Center in Casper, a series of Progressive Rancher Forums highlighting relevant topics for Wyoming cattle producers were held.
As part of the series, Dr. Hannah Hollinger, assistant professor of animal genetics in the department of animal science at the University of Wyoming (UW), gave a presentation on balancing maternal and terminal traits to optimize performance and profit in calf crops.
Balancing genetics
Hollinger’s research fo-cuses on improving production efficiency of ruminant livestock.
Her work integrates components of nutrition, reproduction and genetics to investigate the impact of maternal influence on early rumen microbiome development in offspring as an avenue to improve long-term productivity.
To kick off her talk, Hollinger explained there are three main factors which determine the observable traits of cattle offspring – genetic merit or genotype, environmental influence and residual impacts.
Selecting genetics which achieve the right balance of maternal and terminal traits starts with developing a full picture of producers’ end goals, then accounting for residual impacts such as environmental conditions and management practices.
“One of the best things to think about when balancing maternal and terminal traits is identifying a clear breeding objective,” Hollinger said. “Breeding objective is really important in driving everything afterwards.”
Striking a balance
Mating strong terminal sires to cows with strong maternal strength helps create a balanced, functional offspring, Hollinger explained.
Terminal traits are traits which influence growth and carcass quality, while maternal traits are associated with factors like reproductive capacity and longevity.
Genetic factors in bulls and cows alike influence factors like calving ease, fertility and disease susceptibility.
Hollinger noted expected progeny differences (EPDs) can be useful in assessing performance in bulls and cows, tracking categories from milk production and weaning weight to feed efficiency and carcass quality.
“Utilizing EPDs to our advantage means we have to invest time into understanding all of the different EPDs and true interpretations and limitations of them,” Hollinger said, emphasizing trying to select for too many qualities in one bull or cow can lead to issues.
“If we select for too many traits in one animal, we can lose accuracy and selection intensity,” Hollinger warned.
She also explained the inverse genetic relationship between different traits and different levels of heritability. Carcass and conformation traits are highly heritable, Hollinger said, while traits like temperament and growth efficiency tend to be more moderately heritable.
Achieving goals
Once producers establish a clear understanding of breeding objectives, Hollinger said a few different factors influence how to go about achieving goals.
“Timelines influence what traits you should select now versus ones you may want to look at for a long-term,” Hollinger said.
For example, short-term goals like raising fast-growing market calves requires different breeding considerations than long-term goals like selecting replacement heifers or bull calves to build up a cow herd.
Additionally, Hollinger noted crossbreeding is often one of the best ways to balance maternal and terminal traits if an operation’s goals allow for, and she encouraged producers to familiarize themselves with the strengths and weaknesses of multiple cattle breeds.
“Make sure you’re complementing what you currently have in your operation and what you need to achieve breeding objectives,” Hollinger said.
She also encouraged producers to familiarize themselves with selection indexes, which use industry data to outline expected breeding outcomes in economic terms and can help determine which traits may be most important to attempt to achieve through the breeding process.
Take-home points
In closing, Hollinger offered four take-home points for producers to bear in mind while assessing and selecting genetics – breeding objective, mating system, timeline and whole-herd utilization.
“First and foremost, breeding objective is going to dictate how much balancing you need to do,” she explained, reminding producers to evaluate their operation-specific goals.
Next, she re-emphasized the importance of selecting a mating system which will best aid breeding objectives.
“Clearly defining a timeline will dictate how much emphasis to place on highly heritable terminal traits versus lowly heritable maternal traits,” Hollinger continued.
Finally, she reminded producers to focus on utilizing the entire herd, bearing in mind a single bull will likely not be able to accomplish every breeding goal and encouraging producers to be willing to incorporate multiple bulls into their program.
Grace Skavdahl is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
