Paul Beck, Oklahoma State University Extension Beef Cattle Nutrition Specialist
OSU Department of Animal and Food Sciences and the Oklahoma Cattlemen’s Association are hosting a Beef Finishing Field Day on April 27 beginning at 10 am at the OSU Totusek Arena and continuing after lunch at the Willard Spark Beef Research Unit. This event is being held in conjunction with the Oklahoma Cattlemen’s Association Steer Carcass Challenge and the Oklahoma Junior Cattlemen’s Association Steer Feedout.
Finishing research being conducted at the Spark’s Center will be highlighted. Jacee DeVries, a graduate student in the OSU Department of Animal and Food Sciences, will present research on genetic testing to predict performance. The objective of this study was to determine differences in performance and efficiency of finishing steers with a range of Neogen Igenity Beef scores for average daily gain (ADG) and milk. Angus-sired steer calves weighing 920 pounds were placed on feed at the WSBRC after grazing wheat pasture for 155 days. Steers were grouped based on Igenity ADG Score [low growth (LG) scores 1-4, medium growth (MG) scores 5-6, or high-growth (HG) scores 7-10]. Steers were allocated into pens in heavy and light weight blocks. The genetic test results were not predictive of growth rates during the grazing period. Steers with HG scores consumed more feed during the finishing period, gained weight more rapidly during finishing, weighed more at slaughter, had heavier carcasses, and had higher percentage of carcasses grading USDA Choice than MG and LG steers. According to this data Igenity Beef Index Scores are predictive of growth performance and have the potential to be an effective selection tool.
| Effect of Genetic Test Results on Performance of Finishing Steers. | ||||
| Average Daily Gain Score | ||||
| HG (7-10) | MG (5-6) | LG (1-4) | P-value | |
| Bodyweight, lbs | ||||
| Initial | 914 | 933 | 923 | 0.91 |
| Step-Up | 1169 | 1189 | 1161 | 0.85 |
| Finishing | 1571 | 1518 | 1508 | 0.03 |
| Average Daily Gain, lb/day | ||||
| Step-Up | 7.96 | 8.00 | 7.43 | 0.15 |
| Finishing | 3.77 | 3.35 | 3.44 | <0.01 |
| Dry Matter Intake, lb/day | ||||
| Step-Up | 28.9 | 28.2 | 28.3 | <0.01 |
| Finishing | 32.7 | 30.3 | 30.0 | 0.01 |
| Feed:Gain | ||||
| Step-Up | 3.7 | 3.7 | 3.9 | 0.08 |
| Finishing | 8.6 | 8.9 | 8.8 | 0.37 |
| Hot Carcass Weight, lbs | 946 | 915 | 902 | 0.01 |
| % USDA Choice or higher | 100 | 94 | 90 | 0.01 |