Category: Beef Producers

By Jaclyn Krymowski for American Cattlemen

Genomic testing has made a significant difference in the way cattle are bred and managed.  The technology can help producers isolate noteworthy traits like average daily gain and calving ease to make genetic gains far more quickly than through traditional methods.

Genomic testing can be used by producers with a myriad of objectives, from seedstock to freezer beef to stock show. 

“Genetic verification is particularly useful in situations that involve multi-sire breeding pastures, artificial insemination (AI) or embryo transfer followed by clean-up bulls (natural mating), calves that may have been switched at birth, and ambiguous data records,” write Johnny Rogers and Felipe Silva of North Carolina University Extension in their bulletin Genomic Testing and Its Uses in Beef Cattle.

This information also allows producers to catch errors or mistakes that happened during breeding, like when the wrong straw is pulled at the time of insemination. Incorporating it into the breeding program can ensure accurate data is included in ancestry and herd records.

Background of Genomic Testing

Genomics has been extensively utilized by the dairy sector since its introduction in 2008. Since then, especially with more recent improvements and increased accuracy, beef has followed suit and has quickly picked up its pace in adoption.

“Genetic testing is based on the principles of inheritance. Inheritance is most easily explained using “simply inherited” traits,” explain Jacob Segers and Daniela Lourenco in the University of Georgia Extension bulletin Genomic Testing in Beef Cattle: How Does It Work? “Genomic testing simply inherited traits is controlled by one or a few genes.” 

 Expected Progeny Differences (EPDs) provide a prediction of the genetic transmitting availability and can be used to make selection decisions. For a given trait, EPD values are calculated based on data submitted by producers based on various performance data points. These evaluations, along with related metrics like dollar indexes, are calculated and determined by breed associations and the multi-breed collaborative, International Genetic Solutions. 

It has become standard for many operations to seek bulls with documented genomic testing because of the benefits of parentage verification and the calculation of Genomic Enhanced -EPDs (GE-EPDs). 

However, with more data and more accurate results, more operations are also investing on testing their females as well.

The Benefits

Recently, genomic testing for beef cattle has evolved to include “high-throughput” testing, meaning that thousands of markers (single nucleotide polymorphisms, or SNPs) are read from an animal’s DNA.

Genomics enables more accuracy for younger animals and provides clear information about the genetic traits of interest.

“GE-EPDs are the best estimate of an animal’s genetic value as a parent,” says the Penn State Extension bulletin Understanding EPDs and Genomic Testing in Beef Cattle. “The lack of confidence associated with EPDs on young cattle comes from not having progeny or performance data, both of which increase the accuracy of the EPD.”

An increase in EPD accuracy doesn’t necessarily change the EPD value itself. Instead, higher accuracy gives producers greater confidence in the EPD because it reflects more robust data. For younger animals, genotyping can enhance EPD accuracy by providing valuable genetic insights early on, offering a cost-effective way to maximize the return on investment in breeding decisions.

For producers who sell their entire calf crop at weaning or after a backgrounding phase, these traits can help guide breeding and marketing decisions:

• Birth Weight (BW)
• Calving Ease (CE) or Calving Ease Direct (CED)
• Weaning Weight (WW)
• Yearling Weight (YW)

These traits are especially important as their selection not only adds dollars but can also help reduce the daily production workload.

The technology that evaluates SNPs has evolved rapidly since genotyping first began. Today higher density chips that evaluate at least 50,000 SNPs are used to genotype elite animals for potential marketing, mating and selection. Heifers being tested for herd management decisions are often genotyped with lower-cost, lower-density chips that evaluate 10,000-20,000 SNPs, according to USA Cattle Genetics.

What Does the Future Hold?

Although we have made solid advances in genomic testing, the sky is the limit.

“The big gamble with using EPDs as a fail-safe selection tool is the accuracy of the prediction in young cattle that have few, if any, progeny,” note Segers and Lourenco. “The lack of confidence associated with EPDs on young cattle comes from not having progeny or performance data, both of which increase the accuracy of the EPD.”

As the database continues to become populated with data, the more reliable and easier selections will be. The unknowns will slightly decline as more progeny have data available.

For young sires, most of their genetic value is based on their pedigree. As animals age and produce offspring, their genetic merit and transmitting ability become clearer. This is reflected in the accuracy value of their EPD, measured on a 0–1 scale. A higher accuracy indicates the EPD is more likely to represent the animal’s true genetic value, regardless of whether the EPD itself increases or decreases. For example, a young bull with an accuracy of 0.2 has a more uncertain EPD compared to a proven sire with an accuracy of 0.8, which gives producers greater confidence in the predictions.

Genotyping a young animal boosts accuracy, as DNA tests (SNP genotypes) provide information equivalent to adding data from 5–50 offspring, depending on the trait. DNA samples can be collected early in life, and unlike metabolism or hormones, an animal’s genetic code remains constant. Genomic testing gives producers a snapshot of key genes influencing economically important traits, increasing confidence in GE-EPDs.

Selecting females for replacement is a challenge for commercial cow-calf production and the expense of heifer development. With a solid breeding strategy and specific selection principles, producers can make more accurate and confident selections in determining replacement vs cull heifers.