Genomic Testing – is it worthwhile?

Published on Fri, 12/06/2019 - 11:54am

 Genomic Testing – is it worthwhile?

 By Jaclyn Krymowski for American Cattlemen

 To say the past decade has been revolutionary in the world of cattle genetics is no understatement. Genomic testing, along with subsequent data collection, has been the spearhead of this rapid acceleration, moving the modern cow’s improvement by leaps and bounds. The dairy industry has especially fallen in love with this technology. And while beef is certainly heading that direction, it has not yet reached the same widespread genomic heights of its dairy counterpart.

There is much to evaluate in terms of where genomics stand in today’s beef and where things are going. For many breeders, an investment in genomics is an investment in the future. What that future might be depends on how producers and professionals use and interpret that information. With so much potential going on, it’s worth individual producers to ask – is genomic testing worthwhile?

Decoding information and making it all work
Genomics and all its accompanying technology have been put to use for a while. Right now, the beef industry is a good position to take the next steps and decide how and where to use that information on the industrial and production levels. Typical genomic testing for cattle uses Single Nucleotide Polymorphism (SNP) technology, which uses DNA markers to translate the unique genetic makeup of the individual animal. It can also be used to identify genetic abnormalities and mutations.

Research has told us a lot about how to translate genomic results. Producers can have an idea of how certain animals will perform in specific management situations. For example, according the Beef Cattle Research Council (BCRC), leptin gene codes for a hormone that controls appetite and fat deposits. In cattle, the base pair code of CC, TC or TT, and TT calves can deposit backfat faster and be on feed fewer days than TC and CC calves. This kind of testing can help feedlot operators and cow-calf producers sort calves into more uniform feeding groups for optimal performance. In a similar way, a lot of dairies have invested in genomic testing to assist with making their culling and replacement decisions.

There have been massive changes in even traits of low heritability. Fertility, productive life and health are among these. A lot of time and research is being poured into feed efficiency. Likewise, even the traditional EPDs can be enhanced for reliability when they are genomically enhanced (GE-EPDs). Besides the benefit to the individual producers, there is a lot of merit that can be contributed towards the national herd and industry standards. The information we have from genomics and their reliability is only obtained by data collection. The more data collected, the more we can learn and the greater reliability we have.

While genomics has its benefits, a genomic number on a test or a pedigree shouldn’t necessarily be the end-all-be-all of decision making. As we develop and learn more about this technology, discussion continues on the best way to apply it.

“While genomics works very reliably in cases where the SNP is known to occur within an actual gene, in many cases the SNP may only located somewhere near the gene,” says the BCRC. “In that case, how accurate GE-EPDs or MBVs (Maternal Breeding Values) are will depend on how closely related the animals tested are to the population in which the prediction equations used to generate the GE-EPDs or MBVs were developed.  GE-EPD/MBV prediction equations using SNPs that were discovered in one bloodline may not work as reliably in another, and GE-EPD/MPV prediction equations developed using SNPs that were discovered in one breed are unlikely to produce reliable results in a different breed.”

There are different genomics tests available at different costs, the larger the chip used for the test, the more markers can be identified to obtain more information. Tests can range from less than $20 to nearly $40 and as simple as submitting a hair or blood sample. Many breed associations work with labs and make the sampling and testing process easy, sometimes at a discount when obtained through other services.  

Beyond the bottom line
Besides the productivity advantages, genomics also solves certain genetic issues found in livestock. One USDA statistic suggest one in every five animals is expected to be a carrier of some genetic defect capable of embryonic loss. Thanks to genomics, such animals going into stud service can be identified very quickly. These predictions are so accurate, animals carrying undesirable traits need not even be culled. Instead, their mating can be managed in such a way they pass down their positive traits and mitigate the negative ones. In a similar way, genomics can help reduce the amount of inbreeding.

Health traits and diseases resistance are another area genomics are rapidly working to accelerate. A lot of health and wellness traits tend to have very low heritability. It can take many years of pristine breeding for them to gain little impact in the traditional way. For a long time, they weren’t even major players in sire selection. In less than a decade, they’ve seen massive improvements.

Other welfare-related traits are also on the genomics docket. This includes things like heat tolerance and hoof durability. Some researchers are currently interested in complex genetically-influenced behaviors such as grazing ability and efficiency.

As incredible of an impact as genomic knowledge has already made, the era is still in its infancy and there is much more to be learned and discovered. Beef can be expected to only invest more into genomics via both research and field testing. There’s enough of a future in the technology making it worth a serious look and consideration. Even if not applicable to one’s specific operation and market, directly or indirectly, you can expect genomics to have an impact in the future.