The Dance Steps of Genomics Part II: Using Genomics in Your Herd

by Jared Decker, PhD., University of Missouri Extension

Genomics: We hear this word frequently in the beef industry. But, how do we actually use this technology? More importantly, how do we use this technology to be more profitable?

In “Part I: Understanding Genomic Prediction” we discussed how expected progeny differences (EPDs) and genomic-enhanced expected progeny differences (GE-EPDs) work, the benefit of increased precision with GE-EPDs, and that beef farmers and ranchers can trust this technology. In Part II, we will discuss the steps you can take to start using DNA technology and genomics in your herd in order to be more profitable.

DNA SAMPLES

The most basic step in getting started with DNA testing is collecting a DNA sample. There are many different ways to send in a sample for DNA testing, including a semen straw, ear punch, such as the AllFlex Tissue Sampling Unit, tube of blood, or hair and blood cards. One of the nice features of hair or blood cards is that these samples can be stored at room temperature for decades. Thus, the hair or blood cards can be seen as a long-term storage solution for DNA samples. Further, the processing of blood cards can be completely automated at DNA testing facilities.

There are various resources available to describe how to take a high-quality DNA sample. For a start, see the “DNA Sample Collection” factsheet at eBEEF.org. As some simple rules of thumb, try to make sure that the DNA card is as clean as possible. Also, be sure not to reuse needles or scalpels between animals; we don’t want the DNA sample to contain DNA from multiple animals.

Seedstock producers should consider collecting and storing a DNA sample for every animal in their herd. This can be a resource for future DNA testing.

BULLS

One of the easiest ways to get started with DNA testing is to use bulls with GE-EPDs. I would encourage all producers to only use natural service sires who have GE-EPDs. The easiest way to accomplish this is to simply buy bulls with GE-EPDs.

When buying a bull with GE-EPDs you are substantially reducing your risk of making a bad purchasing decision. The genomic test provides the same amount of information as dozens of calves, with data reported and analyzed, out of the bull. Think about purchasing a bull to use as a clean-up sire on heifers. We want to be quite certain this bull is a calving ease bull. No one wants to be pulling calves the calving season after the new bull is used. Genomic information increases the reliability of EPDs and reduces risk when purchasing bulls.

But, what if you have already purchased the bull—should you have him DNA tested? I would argue even in this case that you should test the bull. Compared with a single cow, a single bull has a much larger influence on the genetics of a herd. Not only does a bull have dozens of calves each year, but in many situations he is the sire of the next generation of cows. By having a better picture of the bull’s genetic merit, we better understand the genetic merit of the calf crop and how they should be managed and marketed. By better understanding the bull’s genetics, we have a clearer understanding of the replacement female’s genetic profile and can select mates to complement her strengths and improve her weaknesses.

Genomic information is only valuable if it is used to improve how we make a decision. Genomic testing allows us to use younger bulls with greater confidence, thus shortening the generation interval, or the average age of parents, and increasing the rate of genetic progress. When testing bulls, we need to use genomic information to decide what semen to purchase, what bull to buy, or how to manage a bull’s calf crop.

COWS AND HEIFERS

While I argue all herd bulls should be DNA tested, much more thought and consideration should be put into the decision to DNA test females.

Consider mature cows. The investment has already been made to purchase or develop this female. Given adequate performance, she will probably stay in the herd the duration of her productive life to see the full return made on the investment in her. There is little economic incentive to DNA test this female, as there is not a decision to be made about whether to keep her. An exception to this suggestion would be if we are considering keeping one of her bull calves as a herd bull.

Heifers are a completely different situation. With each heifer we raise, we have to decide if she will be developed to be a replacement female in our herd, sold as a breeding female in someone else’s herd, or sold as a feeder calf. In many commercial herds there is little-to-no information available to make this decision. In seedstock herds we have EPDs and indexes, but one of the main weaknesses of pedigree EPDs is that they are imprecise for young animals. Genomic testing can solve both of these situations as the genomic test provides more information for the selection decision.

When DNA testing heifers, a plan must be developed to map how we will achieve a return on the investment in genomics. If the genomic testing does not influence a decision, it will be difficult to see a return on the investment. As a general rule of thumb, it is recommended to test twice as many heifers as you plan to keep. This allows the genomic prediction to re-rank the heifers compared with traditional selection criteria.

By putting selection pressure on both the bull and cow side of the pedigree, we can make more rapid selection progress. If we are selecting for profit using economic selection indexes, our herds will become more productive and profitable.

For commercial producers, genomic testing of the heifer crop can be used to market the steer crop. If the entire heifer crop is genomic tested or if a random sample of the heifers are tested, then the average of the heifer crop equals the average of the steer crop. Thus, by testing the heifers, a commercial producer can know the steers’ propensity to gain and grade in the feedlot and on the rail. This information can then be used as a tool to market the steers.

Testing the heifers can happen at different points in time, based on the preferences of the producer and the production system. Some producers favor collecting samples at tagging. Others collect samples at weaning. Still, others wait until they have identified which heifers are AI bred, and only test those heifers carrying an AI pregnancy.

CONCLUSIONS

GE-EPDs and genomic predictions are an exciting new technology. Producers can be fully confident that this technology works, especially within a breed association evaluation setting. But, as with any technology, producers should be thoughtful about how they will see a return on this investment. Investing in genomics will result in more rapid genetic progress if the genomic information is used for selection decisions. Investing in genomics may require different market strategies to see a full return on the investment cheap cialis pills. From only testing herd bulls to testing their entire calf crop, beef producers need to identify what level of adoption of genomic technology makes sense for their herd. As the beef industry continues to adopt this technology, we will see increased genetic improvement.