'We're not actually meeting the mark in all grades,' specialist tells ranchers
By CAROL RYAN DUMAS
The U.S. cattle industry has been trying to improve the beef it produces since the first quality audits in 1991.
The industry has made improvements but has not quite met its goal, experts say.
The last audit did show improvements in quality grade with more prime, more top choice, less select and no standard grades. But the industry is still not producing enough prime, said Benton Glaze, University of Idaho extension livestock specialist during a beef clinic in Lincoln County.
"We're not actually meeting the mark in all grades," he said.
Quality grades measure palatability -- tenderness, flavor and juiciness -- and more people are eating and wanting high-quality beef.
"If we're going to try to improve carcass grade, yield and quality, there are things we need to select for," he said.
Two primary factors affect how a carcass grades, marbling and maturity, but the major factor is marbling. Prime grade has abundant fat with more marbling and the most flavor. Physiological maturity, based on blood flow in the bone, is also a factor, with younger cattle grading better than older cattle.
Components of performance and how the cattle will grade are based on genetics and management and climate.
"Beef cattle evaluation has progressed over time. If we want to make good selection decisions, we need to know genetics," he said.
Visual appraisal doesn't do a very good job of selecting for genetics, but producers can't get a handle on genetics just from performance measures due to environmental factors.
To get expected progeny differences, or EPDs, computers are used to get rid of as many environmental factors as possible, he said.
"EPDs are the best method we have today for predicting an animal's genetic level or genetic worth," he said.
EPDs don't predict actual performance; they predict the difference in performance, are always changing and can't be used to compare across breeds.
Indexes are also used to combine selected traits to make progress on all traits, rather than undoing one by selecting for another. Weighting traits into indexes can help select for several traits at once, he said.
Fifteen to 20 breed associations publish EPDs or indexes for carcass traits. The information also contains accuracy ratings. A low rating means the expression of the trait is very likely to change as more information comes in.
"Carcass traits are controlled primarily by genetics and we can make changes pretty easily. We need to make sure we keep things in balance or we are going to tip the cart," he said.
Some traits are antagonistic. For instance, selecting for yield results in less marbling and vice versa, he said. And reproductive and maternal traits also need to be in the discussion.