A groundbreaking, newly-published study by CAFNR researcher Jared Decker uses genomics and citizen science to help cattle farmers and ranchers across the globe make better breeding selections that will ultimately improve sustainability, animal welfare and profitability of their operations. And, the key to all of this? Hair shedding.
“This project has been really exciting to me because it blends both very basic research all the way to very applied research, so it is one of those rare projects that covers that wide spectrum,” said Jared Decker, associate professor of animal sciences and Wurdack Chair of Animal Genomics.
According to Decker, some cows shed their winter hair more effectively than others. This means that some lose their heavy winter coats during the spring months before the heat of summer sets in while others hang onto portions of that coat well into summer – sometimes as late as August. This is problematic because when the cows retain this winter coat into the warm months, it means they are putting their energy into keeping cool.
“It’s a societal concern because that animal is going to experience more stress, mainly heat stress,” Decker said. “Those animals are also not going to be as efficient. As a consequence of that, they are going to have lower reproduction. Farmers are putting all of these resources into this cow, and they are not going to produce a calf to bring to market.”
Decker further explained that when a cow with remaining winter coat does conceive and produce a calf, that calf is often smaller and younger than its counterparts in the herd.
But, all of this can be mitigated if you can predict which bulls will produce cows that shed more or less efficiently, so, eight years ago, Decker set out to create a prediction tool.
The project was part of a $3 million grant from the USDA NIFA Food Security Program, and Decker’s study was published in the February edition of G3: Genes | Genomes | Genetics, a peer-reviewed journal published by the Oxford University Press on behalf of the Genetics Society of America.
During the five years he worked on this project, Decker and his lab team collected genetic samples from 12,000 cows of 11 different breeds and then asked the owners of those animals to score their hair shedding over time. His team collected more than 38,000 scores. Those scores were then analyzed in tandem with the genetic information and environmental factors like nutrition practices, the climate the cows lived in – which impacts heat stress – and daylight hours.
All that data was then used to create a prediction tool for those 11 breeds that producers can use when making decisions about which bulls to introduce into their breeding program.
If you have Angus cattle, this may sound familiar, as Decker’s former graduate student, Harly Durbin, created a hair shedding prediction tool specific to Angus cattle as a part of her internship with American Angus Association during her studies under Decker’s direction. The prediction is now included in registration certificates provided with American Angus Association animals, and Decker says other associations may follow suit now.
“One of the things I really value is mentoring graduate students and helping graduate students meet their goals,” Decker said. “And, with this project, I was not only fortunate to work with data-driven farmers and ranchers across the US as they helped collect data, but I was also fortunate to work with Harly, who was a highly motivated and very talented graduate student here at MU.”
Durbin has since completed her Ph.D. and is working in industry.
While his prediction tool is now complete, Decker says this project has opened new doors to potential future discoveries that he hopes to pursue.
For one, examination of his data shows that there may be a link between the genes that control pigmentation, or the color of the animal’s fur, and shedding.
“Our results provide further evidence for the cross-talk between the cells that produce pigment and the cells that produce the proteins in hair,” Decker said. “This intricate dance among the genes in different cell types demonstrates the complexity behind traits, even those as simple as the timing of when mammals shed their winter hair.”
The team’s work also found many interactions between genes and the amount of daylight, but almost no interactions between genes and temperature. “The animal’s ability to sense the daylength is having a big impact on shedding,” Decker said. “So, we think there may be something to do with the eye, since that’s how mammals sense light.”
Further research is needed to understand how the associated genes are affecting the structure and function of the eyes.
Regardless of what comes in the future, the results of Decker’s current study can be found in the February edition of G3.