Making the Cut

Harly Durbin has been collecting and organizing hair shedding data

In 2015, Jared Decker, an associate professor in the Division of Animal Sciences and state beef Extension specialist, received a $3 million grant from the United States Department of Agriculture focused on matching cattle to their best environments so producers can make educated decisions about which animals are going to be most productive for them.

Harly Durbin and Troy Rowan (research highlighted here) came to the University of Missouri as graduate research assistants in 2016 to work with Decker on the grant. Durbin’s part of the project has been focused on data collection and organization related to hair shedding.

Hair shedding is incredibly important for cattle, as removing that coat as the weather warms helps regulate temperature and keeps the cow cooler.

“Imagine if you were wearing a full winter coat in Missouri during the summer,” Durbin said. “You probably wouldn’t be very productive because you would be looking for ways to cool down. That’s the same with a cow that doesn’t shed its coat early. They aren’t as productive because they’re trying to find ways to cool down, such as finding shade or sitting in a pond.”

Those cows spending more time trying to thermoregulate are also spending less time with their calf. Durbin said that early summer shedding is an indicator for heat tolerance and tolerance to fescue toxicosis. Fescue toxicosis is one of the biggest economic stressors to the beef industry.

“For producers in heat-stressed areas and producers grazing endophyte-infected (hot) fescue, hair shedding is an evaluation of environmental adaptability and cow performance,” Durbin said.

Durbin organized 35,000 hair shedding scores that included 11 cattle breeds from seven different breed associations. The majority of the data was collected over a three-year period, with scores coming from across the United States.

Cows are scored on a scale from 1 to 5 when it comes to hair shedding. A score of a 5 is a full winter coat and a 1 is completely slick.

“We have data from 13 states, most of which are in the Midwest and southeast,” she said. “We do have one herd in Washington and some in California. With how we advertised it, a good portion came from Missouri, especially those who have been part of past research.

“It was really a win-win for everyone. We got incredible data and producers got a lot of great genomic information back in return. The genotypes we generated went back to the breed associations and into their genetic evaluations, which improved the accuracy of the EPDs they report like weaning weight, etc.”

The goal of collecting that data is to create expected progeny differences (EPDs) that provide estimates of the genetic value of an animal as a parent.

“The next step of this project is to dig into the biology now that we have the data clean and together,” Durbin said. “The focus is on increasing the accuracy of genetic predictions in the future, so it will be key to map the genetic basis of hair shedding and the variances controlling it. If there is a DNA variant that has a large effect on hair shedding, it can be added to a SNP chip in the future. Testing more cattle is critical for this next step.”

Durbin worked closely with the breed associations throughout the project. She also worked with the College of Agriculture, Food and Natural Resources’ Agricultural Experiment Station’s Thompson (Spickard, Mo.) and Southwest (Mt. Vernon, Mo.) Research Centers.

“This was such a good learning experience in terms of coordinating a big project with numerous people,” Durbin said. “There was a lot of back and forth and a lot of data transfer. Timely communication was very important.

“Having herds at two Research Centers was also helpful. We had so much data already in those two locations. That allowed us to have a better understanding about the cows we were working with.”

One of the breed associations, who Durbin interned with last summer, has already released a hair shedding EPD for their specific breed – the American Angus Association. Durbin brought part of her research and combined it with what the American Angus Association already had.

“We worked really hard through the ways to best model this as an EPD,” Durbin said. “It’s super exciting to see them roll it out. It will hopefully get more people interested and we’ll see more breed associations follow suit.

“The internship was interesting in another way, too, because I got to see the data from the industry side. They have production deadlines, and it was exciting to be involved in that.”

Durbin earned her bachelor’s degree at Texas A&M University in animal science before coming to MU.