2012 Annual Report
2. Develop strategies to optimize meat quality and composition traits of meat. a. Develop strategies to improve the value of underutilized muscles. b. Validate that the µ-calpain and calpastatin tenderness markers that were developed and have been verified in structured research populations will be efficacious when applied to the diverse genetics, management systems, and harvesting conditions that occur in the U.S. beef industry. c. Determine the level of differences among lamb breeds in biochemical traits controlling variation in tenderness and develop strategies to exploit these differences to optimize lamb quality and carcass composition.
The capabilities of the existing visible and near-infrared spectroscopy instrument were expanded from tenderness prediction for the ribeye muscle from U.S. Select beef carcasses to also include U.S. Choice carcasses and most other major beef muscles. Measurements could be conducted at the time of grading, after fabrication into individual cuts, or after steak-cutting. This technology also was used to develop a prediction of tenderness and lean color stability for boneless pork loins that could be used to select product for premium programs or for genetic selection. Work from this project also determined that rapid chilling used at some commercial processing plants results in a dramatic decrease in meat tenderness and led to ongoing work to determine the mechanism of this effect and strategies to optimize chilling and its impact on all quality traits.
Research was conducted to develop strategies to increase the value of underutilized muscles from the round and chuck that have favorable eating quality. It was demonstrated that the shoulder clod and the sirloin tip muscles could be used as lower cost alternatives to the popular, but highly variable top sirloin on restaurant menus. It was determined that feeding cattle diets with 20 or 40% wet distillers grains produced carcasses that were heavier, fatter, had lower marbling scores, and were less likely to grade U.S. Choice than cattle not fed distillers grains. A study of 10 sheep breeds characterized carcass and meat quality traits providing information to enable producers to select the optimal sire breeds based on their production conditions and marketing goals.
Assays were developed to evaluate mitochondrial metabolism as a source of variation in lean color stability. This work will continue in the new research project. During beef carcasses grading, the amount of bloom time (exposure to air to increase redness of the muscle) must be a minimum of 10 minutes before carcass grading. However, some plants hold carcasses much longer before grading in an attempt to get carcasses to be graded more favorably. Preliminary data indicate that the beef carcass grading camera prediction of marbling score is not strongly impacted by bloom time. Additional data collection is ongoing as part of the new research project.
Kemp, C.M., Wheeler, T.L. 2012. Effects of manipulation of the caspase system on myofibrillar protein degradation in vitro. Journal of Animal Science. 89(10)3262-3271.
Shackelford, S.D., Wheeler, T.L., Koohmaraie, M. 2012. Validation of a model for on-line classification of U.S. Select beef carcasses for longissimus tenderness using visible and near-infrared reflectance spectroscopy. Journal of Animal Science. 90:973-977.
Shackelford, S.D., Wheeler, T.L., King, D.A., Koohmaraie, M. 2012. Field testing of a system for on-line classification of beef carcasses for longissimus tenderness using visible and near-infrared reflectance spectroscopy. Journal of Animal Science. 90:978-988.
King, D.A., Shackelford, S.D., Wheeler, T.L. 2011. Use of visible and near-infrared spectroscopy to predict pork longissimus lean color stability. Journal of Animal Science. 89:4195-4206.
Shackelford, S.D., King, D.A., Wheeler, T.L. 2011. Development of a system for classification of pork loins for tenderness using visible and near-infrared reflectance spectroscopy. Journal of Animal Science. 89:3803-3808.
Rempel, L.A., Casas, E., Shackelford, S.D., Wheeler, T.L. 2012. Relationship of polymorphisms within metabolic genes and carcass traits in crossbred beef cattle. Journal of Animal Science. 90(4):1311-1316.
Lindholm-Perry, A.K., Kuehn, L.A., Rempel, L.A., Smith, T.P., Cushman, R.A., McDaneld, T.G., Wheeler, T.L., Shackelford, S.D., King, D.A., Freetly, H.C. 2012. Evaluation of bovine chemerin (RARRES2) gene variation on beef cattle production traits. Frontiers in Genetics. 3:39.