By Shelby Mettlen for Angus Media

The last 10 years have been an exciting time to explore genomics, says Ben Hayes, leader of the “1,000 Bull Genomes Project” in Australia. With more than 3.5 million cattle genotyped using genomic-estimated breeding values (EBVs) around the world, cattlemen have access to the greatest degree of precision breeding the industry has seen.

Hayes spoke to Angus producers and members of the American Angus Association this past November at the 2016 Angus Convention in Indianapolis, Ind. With such a large number of both beef and dairy cattle genotyped using genomic-EBVs, it’s time to look at the impact the technology has had on the world’s cattle herd, Hayes says.


Reducing generation interval

“Genomics technology is so powerful because you can get these genomic-estimated breeding values almost at the birth of the animal,” he states. “As soon as you can pull a tail hair or get a sample of DNA from the animal, you can get back these genomic breeding values and start to make selective decisions about those animals.”

As a result, the age of breeding those animals is starting to come down, and that’s leading to more rapid genetic gains, Hayes explains. “We’re turning over generations more rapidly.”

The most significant gains are being seen in the sires-to-breed-sires group, he pointed out, citing information on Holstein cattle taken from the U.S. Holstein database (see graph).

“This is the really pointy end of genetics,” he says. “These are the really elite sires that are breeding the next crop of bulls.”

From 2007 to 2016, for all classes of cattle measured, including cows to breed cows, dams to breed bulls, sires to breed cows and sires to breed sires, there has been a drop in generation interval. As Hayes pointed out, the most significant drop in generation interval has been seen in sires to breed sires, dropping from seven years to just two years.

“The genomic breeding values are so accurate now that these really elite bulls can be identified very early,” he notes.

For all classes of cattle, fertility rate is increasing and a significant increase in genetic gain is being observed, he adds.

So, what else can we do with this technology? Hayes gave three examples.

1. We can add value to breeding decisions by using genomic technology. One way is to add new traits to the selection process, something the beef industry is already exploring. Marbling, fertility and feed efficiency — traits that were difficult to measure just a few years ago — are a few traits for which producers can now find genomic breeding values. In Australia, Hayes notes, a substantial push for a genomic value for heat tolerance is being evaluated. Research conducted during heat events in Australia has proven that heat tolerance is a trait that can be selected for, and Hayes continues to work toward perfecting those values.

2. Genomics can be used within management plans to increase production and profitability. For example, genomics can be used to help producers avoid inbreeding, in turn warding off declines in production and avoiding recessive and lethal genetic defects. A leading Holstein breeder utilized Hayes’s research to test a genomic management plan. Out of 49 heifers, only three full sisters resulted with an embryo transfer program. Those siblings were then profiled to determine what sisters should be mated to what bulls to ensure a lesser degree of inbreeding. “It shows you there’s power in this genomic information to decrease inbreeding without really decreasing merit,” Hayes says.

Another example of using genomics to improve management is prescreening cattle prior to feedlot entry for differences in profit potential, as well as for traits like growth rate, feed efficiency, marbling and disease resistance.

3. A third opportunity for using genomic technology is profiling rumen microbiomes. As Hayes points out, there are differences in the profitability of animals as they go through the feedlot. Some gain efficiently and some don’t. “If you genotype those animals, you’re only getting a handle on the contribution to profit through the feedlot from the animal’s own genome,” he explains. “In fact, every animal actually carries tens of millions, hundreds of millions, even a billion other genomes along with it, and that is the microbes that are in the rumen of our animals. They also contribute to feed efficiency and possibly disease resistance.”

Hayes explains that you can now take a handful of rumen contents, extract the DNA from those rumen contents and profile the rumens of animals. It’s something for the future, he said, but according to a small study profiling the microbiomes of selected animals, it can contribute to greater accuracy in predicting feed efficiency of animals in the feedlot.


What’s ahead

In wrapping up the International Genomics Symposium held at the 2016 Angus Convention in Indianapolis, Ind., three experts gathered for a panel discussion moderated by John Pollak, director of the U.S. Meat Animal Research Center (USMARC) in Clay Center, Neb. Panelists included Ben Hayes, Dan Moser and Stephen Miller.

Moser and Miller with Angus Genetics Inc. (AGI), offered insight into what the affiliate company of the American Angus Association has done, will continue to do and is presently working on to improve the Angus breed through precision genetics, testing and breeding practices.

Miller commended the future of genomics in domestic cattle breeding, saying, “Don’t say ‘no’ to technology,” and asserting that producers must be open to new technology to continue to improve their herds and the Angus breed as a whole.

Moser noted that in years previous he would have “never believed” the advancements in genomics the industry has seen, and that we should “embrace them,” and remain prepared for challenges along the way.

Moser revealed that AGI hopes to soon release an expected progeny difference (EPD) value for carcass tenderness in Angus cattle. He also pointed out work toward EPDs involving regional adaptability, including values for things like fescue tolerance and altitude disease.

Miller pointed out AGI’s progress on structured sire evaluation, and commercial traits and their impacts on cattle health and performance at the feedlot.

Hayes’s goal is to make genomic evaluations effective across breeds and to improve the accuracy and effectiveness of those evaluations in Bos indicus cattle. Rather than just “snapshots across the genome,” Hayes said he wants to “nail the traits that are causing differences.”

Hayes would also like to set the stage for a “consumer acceptability EPD,” by testing steaks ordered by customers and restaurants, and breeding cattle to produce meat with characteristics most favorable to consumers.

All panelists agreed that the value of genomic testing is clear, and that producers, researchers and consumers will continue to improve the technology and benefit from it in the years to come.