2009 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.
In FY 2009, a model was developed to expand the capabilities of the USMARC beef carcass grading camera to make rib dissection based estimates of retail product yield. Additionally, the camera manufacturer added features to aid in proper camera operation as part of gaining USDA-AMS approval for beef grading. In cooperation with industry partners, the effectiveness of these features in increasing the accuracy of the camera system was assessed.
The USMARC noninvasive tenderness prediction system has been shown to accurately sort U.S. Choice and Select carcasses into ribeye tenderness categories. Thus, considerable interest exists in using this technology as part of beef merchandising programs. Some segments of the beef industry desire to apply this technology to beef cuts other than the longissimus. Therefore, experiments were conducted to determine the efficacy of the USMARC noninvasive tenderness prediction system for tenderness prediction of top sirloin muscles. It was determined that the technology could also be applied to top sirloin subprimals to predict tenderness.
With the recent growth of the U.S. ethanol industry, the use of wet distiller’s grain as cattle feed has increased. Previous work indicated that inclusion of distiller's grain in finishing diets was detrimental to marbling deposition and, consequently, to carcass value. A novel experiment examining the effectiveness of feeding high levels of distiller’s grains early in the feeding period and reducing or eliminating distiller’s grains during the latter phase of finishing in mitigating these effects was initiated.
To address color stability problems in case-ready beef packages, novel work was conducted to determine the extent of genetic variation in beef lean color stability.
The effects of genetic tenderness markers on tenderness were assessed on a diverse sample of 2,000 beef carcasses representing all of the major cattle feeding regions. Carcasses were selected at random to represent the diversity of genetics and management systems that occur in the U.S. beef industry. This analysis indicated that genetic tenderness markers are predictive of tenderness variation in cattle subjected to diverse antemortem and postmortem management. This work provides the U.S. beef industry with clear objective data on the expected level of tenderness change that could result from selection for the desirable form of these tenderness markers.
The callipyge mutation in sheep drastically increases carcass yield and muscle size, but has deleterious effects on tenderness. A second mutation associated with the myostatin gene also increases carcass yield. A similar mutation in beef is beneficial for tenderness. An experiment was conducted to determine the interaction between the callipyge and myostatin mutation in lamb. Effects on carcass muscling and leanness were additive, but the myostatin mutation was ineffective in mitigating the toughening effect of the callipyge mutation.
Tenderization of tip side steaks makes new menu item feasible. Under a trust agreement between ARS and the National Cattlemen’s Beef Association, ARS scientists at Clay Center, NE, determined that injection marination could improve the tenderness of tip side steaks. The tip center steak had previously been identified as an economical menu alternative for foodservice outlets. However, tip center steaks are currently only marketed in a subprimal containing the tip side steak, which has unacceptable tenderness characteristics. Restaurants that currently use top sirloin steaks as a low cost menu option could feature tip side steaks in addition to tip center steaks and provide an option that is priced competitively and that will result in similar customer satisfaction.
Genetic tenderness markers are effective under diverse management practices. Genetic markers for beef tenderness have been developed and validated in resource populations, but little information is available to assess their effectiveness under commercial beef production systems. Under a trust agreement between ARS and National Cattlemen’s Beef Association, ARS scientists at Clay Center, NE, determined that genetic tenderness markers were effective in segregating a large, random sample of commercial beef carcasses into tenderness groups. Additional work demonstrated that genetic tenderness markers could, at least partially, mitigate the toughening effects of aggressive growth promotant strategies used by cattle producers. This work provides quantitative evidence of the value of genetic tenderness markers in commercial production systems.
USMARC noninvasive tenderness prediction system can accurately classify muscles other than the ribeye. The U.S. beef industry and the Agricultural Marketing Service have sought implementation of standards for tenderness claims. To this end, industry and AMS need instrumentation to noninvasively predict tenderness of meats. Previously, ARS scientists at Clay Center, NE, had developed a noninvasive method to predict tenderness of the ribeye muscle of U.S. Select and U.S. Choice beef carcasses based on visible and near infrared spectroscopy. The present work demonstrated that the existing system could also be used on the top sirloin. This technology should benefit both consumers and all sectors of the beef industry by facilitating development of premium brands of beef that are consistently tender.
King, D.A., Wheeler, T.L., Shackelford, S.D., Koohmaraie, M. 2009. Comparison of palatability characteristics of beef gluteus medius and triceps brachii muscles. Journal of Animal Science. 87:275-284.