In today’s Beef Buzz, senior farm and ranch broadcaster Ron Hays continues to feature comments from Dr. Bob Weaber of Kansas State from his presentation in the OSU Thursday Ranchers Lunchtime Series on the Tug of War in the Cattle Industry. Part one of the conversation is available here. In todays addition, Weaver outlined why producers should focus not only on carcass traits, but on creating productive, long-lasting mama cows.
Genetics Alone Won’t Solve Every Trait
Weaver said producers need to understand the difference between additive genetics—traits improved through selection tools like EPDs—and non-additive genetics, or heterosis.
“We think about the relationship between the additive and non-additive genetic effects,” Weaver said. “They’re sort of inverse in terms of our ability to capture them across trait complexes.”
When it comes to reproduction and fertility, Weaver said direct genetic progress can be slower. “Our ability to directly improve those through additive selection tools like EPDs, not zero, but it would be relatively low,” he said. “Typically, heritability is in the 10% range, which means that 10% of the difference we observe between individuals is due to genetics transmissible from parent to offspring. Ninety percent of it then is due to environment.”
That makes heterosis especially valuable in maternal traits. “We observe significant improvement in the performance of crossbred cows in fertility and longevity relative to their straight bred counterparts under a similar production environment,” Weaver said.
Carcass Traits Are Different
While maternal traits respond strongly to heterosis, Weaver said carcass traits tell another story. “If we go to the far end of the chain and look at the effect of genetics on carcasses, relatively high heritability,” he said. “In fact, marbling, one of the most highly heritable traits we have available for selection, has low to zero heterosis effects.”
That means producers should think strategically about where to use each tool. “So we need to think about then, how do we leverage these two different sources of genetic merit in our breeding scheme and leverage them to the best of our ability?” Weaver said.
Keep Heterosis in the Cow Herd
Weaver emphasized that the greatest economic value of crossbreeding comes from the cow herd itself. “About two thirds of the economic benefit of a crossbreeding system comes from having crossbred cows,” he said. “That should help us focus then our effort and emphasis on maintaining a crossbred cow herd.”
If producers want to make breed-composition changes, he said it should happen in the calf crop rather than the replacement females. “If we are going to make changes in breed composition that reduces heterosis, we do that in the calf product, not on the maternal side or replacement side,” Weaver said.
The Dollars of Heterosis
Weaver also shared a real-world example using a 100-cow herd over a 10-year period, comparing straight breeding versus crossbreeding. “The heterosis effects are sort of small, single-digit percentage numbers,” he said. “While individually may not seem like a lot, they add up, right? And so collectively, have a big impact in our system.”
Using modest assumptions, Weaver said crossbreeding improved calf survival, added pounds at weaning, and significantly increased pounds weaned per cow exposed. “If you figure out the dollars, then the crossbreeding bit here is worth about $460 per cow per year,” Weaver said. “That’s $460 not on the cow’s lifetime. That’s per cow per year.”
The Beef Buzz is a regular feature heard on radio stations around the region on the Radio Oklahoma Ag Network and is a regular audio feature found on this website as well. Click on the LISTEN BAR above for today’s show and check out our archives for older Beef Buzz shows covering the gamut of the beef cattle industry today.
