Reproductive performance is central to the profitability of beef cattle operations. But while many producers focus heavily on bull selection, researchers at the College of Agriculture, Food and Natural Resources (CAFNR) say herd fertility also depends on understanding female genetics.
Jamie Courter, an assistant research professor and state beef genetics extension specialist in the Division of Animal Sciences, said genomic testing gives producers another tool for evaluating fertility, replacement heifer selection and long-term herd genetic potential. She encourages producers to think of their breeding objective as a “genetic business plan.”
“You need to know where your herd is today, where you want those genetics to be in 10 years and which traits you’re going to select to get there,” Courter said.
As genomic testing has become more affordable, Courter said more producers are beginning to use DNA tools to support those breeding goals. Still, she emphasized that the industry has considerable room for growth in how widely genomic technology is adopted.
“We spend all of this time and effort selecting the bull, but are we selecting the right bull for that cow?” Courter said. “She is the factory. She contributes 50% of her DNA to her progeny.”
Jordan Thomas, an assistant professor in the Division of Animal Sciences and former state beef reproductive extension specialist, encourages producers to zoom out to the whole-system level. He said factors such as body condition, forage quality and calving season length all influence whether cows conceive and stay in the herd.
“Everybody’s talking about holistic health and how diet and lifestyle drive health outcomes,” Thomas said. “On the livestock side, we’ve understood for a long time that reproduction is heavily influenced by that bigger picture. “
In recent years, MU research has helped refine estrous synchronization and timed artificial insemination strategies that improve reproductive efficiency, Thomas explained. This research has resulted in simple protocols producers can follow for earlier-conceiving cows and stronger bottom lines.
“Protocols like 7 & 7 Synch, which my lab has worked heavily on, can result in the majority of the cows conceiving to artificial insemination on the very first day of the breeding season,” Thomas said. “That can really position you to be successful. If you can calve out the entire cow herd over the course of just 45 days or so — instead of several months — everything just works so much better for the business.
A clue to what causes reproductive complications
Research has applications in both human and animal reproductive health.
Our cells constantly receive DNA damage from factors such as ultraviolet rays, irradiation, toxins and chemicals. For women, that can lead to poor egg quality, which in turn can cause infertility, miscarriage, birth defects or genetic disorders.
Researchers at the University of Missouri are now working to better understand a process that can help repair that damage.
In a recent study, a team led by Ahmed Balboula, an assistant professor of animal sciences and researcher at the Roy Blunt NextGen Precision Health building, is studying a process known as autophagy. The unsung hero of cellular biology, autophagy serves as the body’s natural defense mechanism, maintaining cellular health by recycling components and ensuring the body’s systems stay balanced and functional.
Balboula and his research team discovered that in female eggs, autophagy is less efficient when there is moderate or severe DNA damage, which is more common in older women.
“When autophagy activity decreases in DNA-damaged eggs or in maternally aged eggs, which have moderate DNA damage, there is an increased risk for aneuploidy,” Balboula said. “Aneuploidy — an abnormal number of chromosomes in a cell — is the leading genetic cause of miscarriage and congenital birth defects, including Down syndrome.”
Balboula and his team also discovered a possible solution. In the study, they found that by boosting or stimulating the process of autophagy in female eggs, they were able to improve egg quality by reducing DNA damage and the likelihood of abnormal chromosome numbers.
By successfully showing that stimulating autophagy can reduce the levels of DNA damage in female eggs, the findings can open up new directions for improving the quality of female eggs, ultimately improving reproductive health for both humans and animals.
“The deactivation of autophagy that we found is likely just one of many underlying mechanisms contributing to aneuploidy,” Balboula said. “Going forward, I will continue to explore other underlying mechanisms contributing to poor egg quality to ultimately further efforts to improve the quality of female eggs.”