Due to the long generation interval in cattle, genetic improvement, using conventional bull and heifer selection, can be a slow process. However, with the use of modern technologies for genetic selection, producers could speed up the process considerably.
A recent trial conducted by Gardiner Angus Ranch (GAR), Ashland, Kansas, and Zoetis demonstrated the possibility of significantly improving genetic merit and resulting calf value in a single generation through the use of DNA testing and artificial insemination (AI) using top-quality sires.
For this trial, the research group purchased 104 mixed-breed yearling heifers one Texas ranch in April 2012. These heifers were not expected to be strong for marbling and quality grade potential. The researchers DNA tested the entire group using the Zoetis GeneStar MVP test. Heifers in the bottom third for marbling potential were culled, while the top two-thirds were bred using AI to high growth and carcass GAR Angus sires. The resulting calves were managed traditionally, DNA tested, fed in a southwest Kansas feedyard and harvested in June 2014.
The DNA tests on the original group of heifers showed that on average, they were well below average for marbling potential based on the Zoetis MVP score. After the researchers culled the bottom one-third based on marbling scores, the remaining heifers averaged near the industry average for marbling potential.
Those selected heifers were bred to two GAR sires that rank in the top 6 percent of the Angus breed for calving ease and top 1 percent for the $B index, which combines measures of growth and carcass value.
DNA testing of the progeny showed an average MVP marbling score of +53, which compares with an average of -21 for the original group of heifers and a -5 average for the heifers retained for breeding.
More importantly, the entire calf crop averaged 94.6 percent USDA Choice and higher, 5.8 percent Prime and 35 percent qualified for the Certified Angus Beef program. There were no heavy or light carcasses and grid premiums for the group averaged $113per head.
As producers around the country begin to rebuild their herds after years of drought-induced liquidation, they have an opportunity to improve the genetic merit of their cow herds through careful heifer and bull selection. The results of this study suggest that investments in DNA testing and AI could generate significant improvement in a relatively short time.