“Is it worthwhile to try and match your genetics to the environment?” Jared Decker, Wurdack Chair of Animal Genomics at the University of Missouri posed the question during his presentation at the Beef Improvement Federation (BIF) Symposium in Knoxville, Tenn., June 11.

Environmental stressors, like fescue toxicosis, cost the beef industry approximately $1 billion a year, said Decker. He shared a study conducted in the 1960s that moved cows from the Brookfield Research Station in Florida to the research station in Miles City, Mont., and cows from Montana to the station in Florida. Pregnancy rates for the cows relocated to Florida from Montana were 55%. In comparison to the Hereford cows native to Florida, this was 28% lower, making a strong case for genetic by environment (G x E) interactions.

Reproduction is one of the traits most affected by G x E interactions, Decker said. Body condition and metabolism are the other two traits most affected.

Decker introduced BIF participants to three USDA-funded projects currently under way to study the effects of, and best ways to address, G x E interactions. In multiple studies from the first project, genes tagged by G x E interactions and selection for local adaptation had functions affecting blood vessel constriction/dilation. This is an important indicator of fescue toxicity, altitude stress and thermotolerance. Additional genes associated with G x E effects were involved in immune response and metabolism. These functions affect the animal’s ability to adapt to their environment and deal with multiple stressors.

“If you are describing your cattle as ‘adaptable’ without actually measuring their ability to sense and respond to environmental stressors, you’re just telling us stories.” — Jared Decker

“Adaptability is defined as an animal’s ability to appropriately sense and respond to the environment,” Decker said. “If you are describing your cattle as ‘adaptable’ without actually measuring their ability to sense and respond to environmental stressors, you’re just telling us stories.”

The latter two projects Decker described are designed to develop tools to help producers measure and match genetics to their environment more effectively than just buying animals from similar environments. Decker advised using expected progeny differences (EPDs) and crossbreeding to address G x E interactions.

“We have the technology now to measure traits that are greatly impacted by environment and generate genetic evaluations for these traits,” he said.

Decker discussed examples of genetic evaluations for fertility; pulmonary arterial pressure (PAP), which occurs in environments of high altitude; and hair shedding, which can address thermoregulation and sensing changing seasons.

“Hair shedding is an economically relevant trait, and I challenge anyone who doesn’t think so to come mend fence with me while wearing their winter parka,” Decker explained.

He tied addressing G x E interactions with biological rules like Bergmann’s rule and Surface law. He suggested leveraging new technologies like 3D imaging to measure surface area for truer genetic evaluations of metabolism than body weight.

To watch Decker’s full presentation, visit https://youtu.be/I5-6tR-XzJg.

Editor’s note: This article was provided courtesy of the Beef Improvement Federation. For more information about this year’s Symposium and BIF’s overall mission, including additional presentations and award winners, visit www.bifsymposium.com. [Lead photo by Shauna Hermel.]
Angus Beef Bulletin EXTRA, Vol. 16, No. 8-A