Comparison of Igenity Silver Profile and Zoetis Predic Gen DNA Tests in Crossbred Beef Cattle

Recently several standalone DNA tests for beef cattle have been introduced to the marketplace. Two of these tests are the Igenity Silver Profile (Neogen, Lincoln, NE) and Zoetis PredicGEN (Zoetis Animal Genetics, Kalamazoo, MI). The Igenity Silver Profile estimates genetic merit for calving ease maternal, stayability, residual feed intake, average daily gain, tenderness, and marbling. The Zoetis PredicGEN estimates genetic merit for tenderness, marbling, and yield grade. No data is available that directly compares DNA test results from these two panels on the same sample of crossbred cattle. Our objective was to estimate correlations between test results from these two DNA panels. Steers (n=160) were sampled from the South Dakota State University Calf Value Discovery (CVD) Program. The primary purpose of the CVD Program is to help producers make educated decisions about retaining ownership of calves through the feedlot. Nine producers shipped anywhere from 6 to 73 steers to VanderWal Farms (Volga, SD) feedlot in December 2015. Hair follicles were collected from steers and shipped to Zoetis Animal Genetics and Neogen Corporation for DNA testing. The Igenity and PredicGEN panels successfully genotyped 159 and 103 steers, respectively. Pearson correlation coefficients were estimated between test results for each weight gain and carcass trait, both within each DNA panel and across the two panels. Within the PredicGEN DNA panel, tenderness was positively correlated with marbling (r = +0.26, P = 0.008) and negatively correlated with yield grade (r = -0.31; P = 0.001), while marbling was negatively correlated with yield grade (r = -0.58; P<0.0001). Within the Igenity Silver Profile, marbling was positively correlated with average daily gain (r = +0.35; P<0.0001). Across DNA panels, tenderness (r = +0.76, P<0.0001) and marbling (r = +0.49; P<0.0001) tests were positively correlated. The PredicGEN yield grade test was negatively correlated with Igenity tenderness (r = -0.45; P<0.0001) and marbling (r = -0.35; P = 0.0004). The PredicGEN marbling test was positively correlated with Igenity average daily gain (r = +0.34; P = 0.0004) and tenderness (r = +0.24; P = 0.017). PredicGEN tenderness was positively correlated with Igenity marbling (r = +0.24; P = 0.013). The tenderness DNA tests by PredicGEN and Igenity are highly correlated while the marbling DNA tests from both companies are only moderately correlated. Producers are therefore more likely to observe greater differences between PredicGEN and Igenity Silver DNA profiles for marbling than tenderness.