Over the Fence with Megan Rolf, Ph.D. by Angela Vesco

During the member education committee meeting at the American Gelbvieh Association (AGA) National Convention in Wichita, Kansas, the AGA has invited Megan Rolf, Ph.D., assistant professor of animal breeding at Kansas State University (K-State) to visit with the membership about genomics.

Megan Rolf is a Kansas native, growing up in LeRoy, on her family’s row crop and cow-calf operation. Rolf ’s involvement in the beef industry started young. She was involved in 4-H showing heifers and was a member of the North American Limousin Junior Association and was on the junior board of directors. Rolf received her college education from K-State and completed her postgraduate degrees at the University of Missouri.

First off, let’s explore the process in which a blood/hair/ tissue sample ends in GE-EPDs. How does that happen?
“Essentially, once the sample is collected, it is routed through the association and submitted to the testing company. Samples are inventoried, the DNA is extracted, and samples will be run in batches according to the number of samples that can be run on a particular assay (genotyping product). Once the samples are genotyped and the data is processed, it will be returned to the breed
association for inclusion into the next National Cattle Evaluation run. There is a lot of work that goes into a genomic-enhanced (GE-EPD) behind the scenes, but from a producer’s perspective, collection of a good DNA sample is the hardest part of this process; you get a good sample and send it in properly and the hard work is done,” Rolf said.

How do genomics impact the commercial producer’s herd when they buy bulls with GE-EPDs? Why is it important for all producers to pay attention to genomics?
GE-EPDs increase the accuracy of breeding decisions. “The main impact of a GE-EPD for a commercial producer is the ability to have a higher accuracy EPD with which you can make selection
decisions. Especially when considering purchasing a yearling herd sire that doesn’t have any progeny recorded yet, this extra accuracy can help them choose a sire with more confidence that he fits their selection criteria and breeding objective. At the moment, genomic technologies are seamlessly integrated into the selection tools we already have available, which is great and provides additional, useful information in a package that we’re already used to using.”

What is the future for genomics?
“I think the future for genomics is bright,” Rolf said. “In my mind, we’re just scratching the surface of what we might be able to do in the future. There are a lot of aspects of genetics/genomics (including imprinting, noncoding RNAs, methylation, histone modification, etc.) that impact phenotype through regulation of the genes that are inherited but that we haven’t had the technology to explore previously on a genome-wide scale.”

“I think some of our greatest insights into the biology of beef cattle will come when we can integrate all of these technologies into a better understanding of the underlying biology of how a  phenotype is created through the complex interaction of inherited DNA (and the mutations it contains) and gene regulation, which can then be translated into genetic selection and/or management tools that producers can utilize.”

What are the future traits that we will be able to predict?
Rolf understands that there are some challenges that impede the process of developing future traits. She says that imagination and the technical capability are two of the limiting factors right now. “Generally, the limiting factor for genomic prediction of novel traits is the need to have a large number of phenotypes on whatever trait you’re interested in predicting” Rolf explained. She
notes that utilizing a large sample size can be expensive and/or complicated and that collecting enough phenotypes to develop a solid selection tool requires a lot of time as well.
Rolf emphasizes how important it is for the selection tools developed to be accurate and effective. “I think this is where a selection index can play a big role in helping place appropriate balances on traits in a defined selection program to help correctly balance out an ever increasing amount of information.”

Is there anything else regarding the future of breeding and genetics that cattle producers should be aware of?
“I think the best bit of advice I can give is that genetics is pretty fast-paced. If they keep an eye on trade publications, and come to conferences like the national convention, I would guess that they’ll be pretty well informed on new developments! I think the next thing that is/will be making a splash is the potential to leverage genomic sequence data, such as what is being done in the fertility project at the University of Missouri and collaborators.”

The American Gelbvieh Association is one of the collaborators on this project. The study is aimed at identifying the genetic cause of less than 100 percent conception rate in cows and then  potentially developing a tool to select breeding stock.