Identifying genetic markers that influence beef cattle reproduction and fertility

By Lilian Schaer for Livestock Research Innovation Corporation

Fertility plays a major role in the profitability of beef and dairy animals, but reproductive problems increasingly plague cattle herds, impacting both animal health and welfare and farm business profitability.

According to University of Guelph beef geneticist Prof. Angela Cánovas, the reproductive failure rate in dairy herds of cows that either are not pregnant or lose an embryo runs as high as 36 percent, and at approximately 30 per cent in beef cattle.

“Whether animals are bred through artificial insemination or natural breeding, some get pregnant and some do not, or suffer early embryonic loss,” says Cánovas. “Part of this variation could be due to genetics and if we know which animals have these traits, we can more accurately select and keep the best animals in a herd.”

Cánovas is leading a research team that has developed new software that has identified areas of the cattle genome that influence reproductive success and failure. This work is now being validated in both beef and dairy herds of various breeds, including collaboration with the American Angus Association. This gives researchers access to a database of almost one million Angus cattle genotypes and phenotypes to validate their findings.

According to Cánovas, it was a previous focus on improving cattle production traits that is a significant cause of the high reproductive problem rates now being seen in cattle herds. This means that when she’s now looking for genetic markers impacting fertility, it’s important to verify this won’t have a negative impact on other traits also being selected for, such as health, feed efficiency, and meat quality.

“To be sure that improving a specific trait doesn’t affect others, we need to perform advanced genomic analysis to study the relationship between those other traits – this type of work is also part of this project,” she says.

For example, Cánovas is also leading a related feed efficiency project that’s identifying genetic markers associated with higher nutrient absorption. The final objective is to identify markers that will improve reproduction without negatively impacting feed efficiency or, when possible, to identify those markers that will improve both reproduction and feed efficiency, among other traits.

Once the research validation phase of the reproductive project is completed, Cánovas will be collaborating with genetics companies to commercialize her findings. For example, the American Angus Association already has a specific genotyping panel for Angus, so the markers identified through this project could be included there for producers to access.

According to Cánovas, this type of genetic improvement work makes it extremely important for beef producers to routinely measure and record traits in their herds, as well as genotyping their animals through their breed associations or through software like Go360bioTrack.

That’s a program that had its start in beef genetics testing with AgSights (formerly Beef Improvement Ontario – BIO) that lets farmers track everything from livestock inventory numbers and animal movements to pedigree, reproduction, health, and body condition scoring information. A genotyping option in the software lets users perform genetic evaluations of their cattle for economically important traits.

“Canada is not a leader in this area, but other countries complete this routinely in beef,” Cánovas says, adding that the information is critical to helping beef producers and breeders make the best genetic selection decisions, including selecting for animals with strong reproductive traits.

“You will know when an animal is born whether she is genetically a good candidate to keep or not. When you genotype calves, you’ll know which ones could have reproductive problems later on in life,” she added.

Ultimately, those genetic decisions could be made at the semen or embryo level so there won’t even be a need to cull genetically undesirable animals, resulting in lower costs for producers and higher animal health and welfare.

“The beauty of this project is that we can go deep and identify good or bad mutations and whether the problems come from the dam or the sire,” she says. “We are able to identify at which stage the problems happen, whether before pregnancy or at what stage during pregnancy.”

Phase one of Cánovas’ reproductive research project was funded by Beef Farmers of Ontario (BFO), and wrapped up at the end of 2018.

Additional funding for the next stage, which will end in 2021, has been secured from BFO, the new federal Beef Cattle Research Council beef research cluster announced by Agriculture and Agri-Food Canada last year, the American Angus Association, Semex and AgSights.

This article was published in Ontario Beef February 2019. It is provided by Livestock Research Innovation Corporation as part of LRIC’s ongoing efforts to report on Canadian livestock research developments and outcomes.