Farm Director Ron Hays is featuring comments from Dr. Dale Woerner, Cargill Endowed Professor in the Department of Animal and Food Sciences at Texas Tech University from a recent conversation he is featured in on the Angus at Work Podcast. Woerner is talking about problems with the current yield grade system.
Yield grade is a calculation that was developed using statistical regression techniques. Ultimately, the equation used hot carcass weight, ribeye area, fat thickness of the twelfth rib, then internal (pelvic, kidney, and heart fat). As those measurements are inputted into the equation, it computes a number scale ranging from 1 to 5 in yield grade. Yield grade 1 indicates the leanest, highest-yielding cattle and 5, the fattest, lowest-yielding cattle.
Dr. Woerner explained that the current yield grade was developed from research conducted in the late 1950s, was completed and published in 1960, and then implemented in 1962. Since then, cattle have changed drastically.
“We’ve gone from purebred Angus and Hereford cattle in the mix of cattle that were used to develop the yield grade equation,” he said. “Clearly, we have evolved from that, not only in cattle genetics and type, but also in management.”
He detailed that people have questioned the accuracy of yield grade since the 1960s. Since the early 2000s, it has been under even greater criticism.
“The yield grade equation is highly inaccurate in truly explaining differences in red meat yield, which is essentially the muscle, fat, and bone makeup of carcasses which translates to what we can sell from a carcass.” Dr. Woerner stated.
He added that there isn’t a good indicator with yield grade to separate and incentivize red meat yield in cattle because of the inaccuracy of the yield grade equation.
Yield and quality grade are the two primary factors outside of hot carcass weight in grid-based value systems. Graders are still very dependent on reliable marbling scores as an indicator of eating quality.
Even measuring the ribeye area as a quality indicator has its own issues. “Ribeye area is something our industry has utilized as an indication of muscling because of its relationship to yield grade calculations,” Woerner said. “Unfortunately, the relationship between ribeye area and true carcass muscling has grown apart to the point where ribeye area doesn’t explain very much at all about the true variation in muscularity.”
He explained that if you take ribeye area and red meat yield from a carcass, it is only about 4% related. “That is because of bones and fats and a lot of other related variables. We’ve done a good job over the last several years of improving ribeye area,” he said.
Watch for tomorrow’s BeefBuzz to see what other technology Dr. Woerner knows to be better for the industry, and listen to the full Angus at Work Podcast here.
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 at the top of the story for today’s show and check out our archives for older Beef Buzz shows covering the gamut of the beef cattle industry today.
