Technology 2-step research project: Genetic improvement made through use of DNA testing and artificial insemination to high-growth, high carcass value angus sires

Abstract Text: Through the use of breed associations and herd health databases, the beef industry has improved the recording of pedigrees and performance data.  Constant evaluation of genetics and performance has allowed producers to make more informed breeding decisions that help improve herd productivity.  However, as a result of recent droughts and elevated feed and grain prices, the American cowherd is at a record low, 38.5 million head. For the United States to continue to be the leading producer of beef in the world, the industry must adopt technologies that improve the efficiency of the cowherd and the quality beef being produced. The objective of this research project was to increase the marbling and grid premium potential in a cow base with average to below-average genetic potential in one generation.  In April 2012, 104 yearling heifers were obtained from a single ranch source that was not expected to have a strong genetic potential for marbling. All heifers were DNA tested for predicted marbling potential, and all heifers had below average GeneSTAR^®DNA marker predicted marbling values.  Heifers in the bottom third for marbling potential were culled.  The predicted marbling values were -4.69 and -52.17 (P < 0.01); SEM = 3.67) units below population average for retained and culled heifers, respectively. Retained females were bred A.I. to one of two Angus sires selected for high growth potential and increased carcass quality.  Reference sires ranked in the top 6% of the breed for calving ease and the top 1% for $B. Resulting calves (n=35) were managed traditionally, DNA tested, fed in a southwest Kansas feedyard, and harvested in June 2014.   When compared to dam DNA, progeny showed predicted marbling scores 54.51 units higher (P < 0.01).  On the rail, progeny recorded an average hot carcass weight of 373.39 kg and a 2.91 average yield grade.  Progeny graded 94.6% USDA Choice or higher. Of those, 5.8% graded USDA Prime, and 35% qualified for the Certified Angus Beef brand.  There were no differences in quality grade, yield grade, or price per cwt between sires (P ≥ .19).  With no carcasses taking weight discounts and an average dressing percentage of 64.92%, there was a $113.10 grid premium per head.  The results from this study demonstrate the improvement that can be made in one generation by using DNA technology and proven sires simultaneously.

Keywords: genetic improvement, beef cattle, carcass quality.