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Environment figures into selection

by Wyoming Livestock Roundup

When it comes to genetics, “no one size fits all.” Although producers have some control over the sires they select based on expected progeny differences (EPDs) and genomic testing, they are still at the mercy of the environment when managing their beef herds.

Dan Moser with the American Angus Association (AAA) tells producers that although genetic change in the commercial herd takes place primarily through sire selection, significant environmental factors can also influence change in the herd.

Producer decisions

“EPDs are the statistical prediction when all the variables come together that allows the comparison of two animals,” Moser says. “However, EPDs don’t predict at an absolute level.”

“I get the question all the time that, if I want to buy an Angus bull that will produce calves 75 pounds heavier at weaning, what EPD should I use? There is really no correct answer to that because the environment plays a role,” he continues.

“It depends on rainfall, genetics of the cowherd, health status and how the cattle are wintered. All of those environmental factors figure in to an absolute value,” Moser explains.

Moser does say that if two bulls have a 20-pound difference in weaning weight EPDs, at $1.75 a pound, producers could be looking at netting an additional $35 a head, just by choosing the higher weaning weight EPD sire.

Association use

Since the 1990s, the AAA has used EPDs extensively to make significant changes in the cowherd.

“We have been able to increase weaning weight and yearling weight, keep cow size about the same and reduce birth weight. That’s what EPDs can do for us,” he says.

In fact, Moser says selecting bulls for calving ease shortens gestation, which reduces birth weight.

EPDs are garnered from pedigree information and performance data. At AAA, data is updated on a weekly basis.

“We only have good information because our producers are willing to trudge through the mud to take a birth weight or put an animal through the chute on a not-so-nice day,” he says.

Future change

Moser talks of how EPDs will change even more in the future.

“It is the best indicator we have right now of what the sire will perform like in the herd. In the future we may have new technology, like gene editing, that could make our cattle even better,” he says.

Gene editing is currently being used in the competing proteins pork and poultry. In one instance, it is being used to develop hogs that are born resistant to certain diseases. In the dairy industry, it could be used to produce Holstein calves that are born polled.

“This provides us with a greater opportunity to design genetics that work in a lot of different environments,” he says.

With the inception of genomic testing, cattle can now have more traits evaluated at a younger age.

Previous data and DNA samples can help indicate how a yearling bull may be expected to perform. Feed intake and feed efficiency testing is just getting underway in the beef industry, but it has made significant changes to the pork and poultry business.

“Genomics allow us to manage risk,” Moser says.

Genomic testing

“For seedstock producers, we think there may be some benefit to genomic testing cows. A pedigree can only tell us so much. There is also the random draw of genetics, which is what makes siblings different from one another even if they share the same parents,” he explains

“DNA technology can look at these genetics and tell us which cows have advantages and which ones don’t,” Moser continues.

Some producers also see value in testing their replacement heifers. Moser cautions that DNA tests are breed specific, and one test will not work for all breeds.

“If ranchers are doing a DNA test, they should use a product that is compatible with the breeds you have,” he says. “The markers are pretty specific.”

A commercial heifer test is available for heifers that are at least 75 percent Angus. Moser says they cannot guarantee the test results for heifers that are less than that.

Producers can also take advantage of a sire match test that can determine which bulls sired which calves if the bulls have been tested. Moser shares some situations where this test could be quite beneficial.

“This test can tell us how many calves each bull sired, and it allows us to evaluate each set of calves from a particular sire to see which one produces the better calves. It can also help determine how many bulls we actually need during breeding season,” he explains.

Gayle Smith is a correspondent for Wyoming Livestock Roundup and can be reached at

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