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United States Department of Agriculture

Agricultural Research Service

Research Project: STRATEGIES TO OPTIMIZE CARCASS YIELD AND MEAT QUALITY OF RED MEAT ANIMALS
2012 Annual Report


1a.Objectives (from AD-416):
1. Develop and evaluate non-invasive instrumentation to predict value determining characteristics of meat. a. Develop and evaluate non-invasive instrumentation to measure maturity and lean color for on-line quality grade determination of beef carcasses. b. Continue improving our non-invasive instrumentation to predict meat tenderness and expand its capabilities to include use on multiple quality grades, muscles, and species. c. Develop technology to predict and improve lean color stability in beef. d. Determine the relationship between instrumental assessment of beef carcass yield grade and wholesale rib dissection-based estimates of beef carcass retail product yield.

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.


1b.Approach (from AD-416):
The VBG2000 image analysis system will be used to develop measurements for carcass maturity and lean color for quality grade determinations of beef carcasses. The VBG2000 system will be used to obtain instrumental measurement of retail product yield for use in genomic analyses. Non-invasive meat tenderness prediction will be expanded to include measurement on U.S. Choice beef carcasses, pork loins, and muscles in addition to longissimus. Strategies to predict and improve lean color stability of beef will be developed. The relative role of connective tissue, muscle shortening, and postmortem proteolysis and their interaction with one another on tenderness of various muscles will be used to develop muscle specific quality improvement strategies to overcome both within and among muscle variation. These strategies may include combinations of antemortem management and genetics utilization as well as postmortem processing methods, marination, and cooking methods to optimize meat tenderness. The µ-calpain and calpastatin tenderness markers that were developed and have been verified in structured research populations will be validated to be efficacious when applied to the diverse genetics, management systems, and harvesting conditions that occur in the U.S. beef industry. The level of differences among lamb breeds in biochemical traits controlling variation in tenderness will be determined and strategies to exploit these differences to optimize lamb quality and carcass composition will be developed.


3.Progress Report:
This is the final report for the 5 year project 5438-31430-004-00D, which terminated July 31, 2012 and was replaced with project 5438-31430-005-00D “Strategies to Optimize Meat Quality and Composition of Red Meat Animals.” Over the lifespan of this research project, significant progress was made in providing the red meat and livestock industries with information and tools to improve meat quality and composition. Non-invasive technology to predict meat tenderness was expanded to numerous other applications. Strategies were demonstrated to increase the value of underutilized muscles. DNA markers for beef tenderness were validated. Lamb breeds were characterized for carcass and meat quality traits. The impact of rapid chilling on pork loin tenderness was demonstrated. The impact of feeding cattle wet distillers grains on carcass traits was determined.

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.


4.Accomplishments
1. Impact of long aging times on meat quality attributes. Storing vacuum packaged beef cuts for up to 42 days is a common practice to ensure desirable tenderness. However, few data are available on the effects of lengthy storage on flavor, lean color, and color stability of steaks. ARS scientists at Clay Center, Nebraska, demonstrated that increased aging time was associated with decreased lean color stability and increased tenderness, but had little effect on beef flavor profiles. These results highlight for the beef processing industry the importance of balancing positive and negative effects of increased aging time with the intended use of the product.

2. Light source stability increases accuracy of beef carcass grading camera. Variation in light sources among beef carcass grading cameras has created grading differences that significantly impact carcass value. ARS scientists at Clay Center, Nebraska, collaborated with both the instrument manufacturer and commercial beef processors to develop an accurate predictor of carcass grade for use with both LED and Xenon cameras. The predictive formula was approved by the USDA-Agricultural Marketing Service(AMS)and is being adopted by the beef packing industry. These efforts will further enhance the accuracy and implementation of instrument grading for beef.


Review Publications
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.

Last Modified: 10/30/2014
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