Built to Move
By Troy Smith
Beef cattle breeders have more tools than ever before to use as aids in selecting breeding animals, including expected progeny difference (EPD) values for various traits, selection indices and genomics. However, there are no “numbers” that are predictive of the structural superiority of one animal over another. Not yet, there aren’t.
EPD values for soundness traits are coming. In fact, the American Angus Association Jan. 30 released research EPDs for foot angle and claw set.
Without numbers, visual appraisal by a practiced eye is necessary to evaluate animals for structural soundness. Cattle structure and its importance to functional mobility was the topic of a Cattlemen’s College session Jan. 31 during the 2018 Cattle Industry Convention in Phoenix, Ariz. Sharing tips for evaluating cattle conformation were Shane Bedwell of the American Hereford Association and Bob Weaber of Kansas State University.
“Looking for structural correctness, or the lack of it, is critically important to functional longevity in the real world,” said Bedwell, noting how poor structural conformation can cause joint weakness, injury and inability to perform in the breeding herd. He advised producers to look at “the angles.”
Bedwell said functional cattle should have correct angles to their shoulders, hips, hocks and pasterns. He said 45 degrees is ideal for the slope from the top to the point of the shoulder and for the slope from shoulder point to elbow joint. In the hindquarters, 45 degree slopes are also most correct for the line from pin bone (hip) to stifle joint and also for the line from stifle to hock.
Angles that deviate too much — particularly if they are too straight — cause mobility problems, said Bedwell. Typically, the animal won’t track straight, and the hind feet won’t step in the tracks of the front feet. Improper pastern angles can also lead to hoof wear problems.
Weaber allowed that making breeding decisions focusing primarily on the numbers with too little attention to phenotypic evaluation probably has led to some structural issues among cattle of various breeds. He also explained research that indicates that the genetic heritability calculations for most structural traits are similar to those of growth and carcass traits. Therefore, EPDs for structural traits, when they become available, can help producers make fairly rapid progress through genetic selection.
Editor’s Note: Troy Smith is a freelance writer and cattleman from Sargent, Neb.. This article was written as part of Angus Media’s coverage of the 2018 Cattle Industry Convention in Phoenix, Ariz. Jan. 29-Feb. 2. See additional coverage in future issues and online at www.angus.org.