Coupling of Image Analysis and Tenderness Classification to Simultaneously Evaluate Carcass Cutability, Longissimus Area, Subprimal Cut Weights, and Tenderness of Beef1
S. D. Shackelford2, T. L. Wheeler, and M. Koohmaraie
Roman L. Hruska U.S. Meat Animal Research Center, ARS, USDA, Clay Center, NE 68933-0166
ducted to determine whether image analysis of the 12th-rib cross-section used for tenderness classifica- tion could accurately predict carcass cutability, longis- simus area, and subprimal cut weights. The right side of crossbred steer and heifer carcasses (n = 66) was fabricated, and the yield of totally trimmed retail product was determined. Following procedures that we
tenderness classification, was removed from
12th-rib region of the left side of each carcass, and image analysis was conducted using off-the-shelf technology. Image analysis accounted for more of the variation in retail product yield (RPYD; 89 vs 77%) and retail product weight (95 vs 90%) than did calculated yield grade. Also, image analysis accurately p r e d i c t e d l o n g i s s i m u s a r e a ( R 2 = . 8 8 ) . F o r m o s subprimals, the combination of image analysis- predicted RPYD and hot carcass weight (HCW) accounted for more of the variation in subprimal t
weight than did the combination of calculated yield grade and HCW. Whereas HCW, by itself, accounted for only 30 to 34% of the variation in weights of round cuts, the combination of image analysis-predicted RPYD and HCW accounted for 78 to 82% of the variation in weights of round cuts. Hot carcass weight, the combination of calculated yield grade and HCW, and the combination of image analysis-predicted RPYD and HCW accounted for 54, 83, and 91% of the variation in the weight of 80% lean trimmings. Thus, image analysis could be used by the beef industry to more accurately predict individual subprimal weights. In turn, that information and appropriate price extensions could be used to more accurately estimate carcass value. Thus, image analysis could be used by the beef industry in combination with tenderness classification to accurately characterize beef carcasses for cutability and tenderness. These tools should help facilitate the development of value-based marketing systems.
Key Words: Beef, Carcasses, Cutability, Instrumentation, Tenderness
1998 American Society of Animal Science. All rights reserved.
J. Anim. Sci. 1998. 76:2631–2640
Image analysis has been shown to accurately predict 9-10-11th rib (r = .81; Cross et al., 1983) and carcass (r = .88; Jones et al., 1992) composition under
1Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of other products that may also be suitable. The authors are grateful to Patty Beska, Kathy Mihm, Pat Tammen, and Mike Thoesen for their assistance in the execution of this experiment and to Marilyn Bierman for her secretarial assistance.
2To whom all correspondence should be addressed: phone: 402/ 762-4223; facsimile: 402/762-4149; E-mail: firstname.lastname@example.org. usda.gov
Received February 9, 1998. Accepted June 15, 1998.
controlled conditions. However, application of image a n a l y s i s i n h i g h - s p e e d b e e f p r o c e s s i n g p l a n t s ( r 2 = . 5 and .55 for Wassenberg et al., 1986 and Belk et al., 1996, respectively) has been less successful, partly because it is difficult with high-speed, on-line grading to consistently position a camera so that it can record an image of the entire longissimus and its surround- ing fat cover (J. W. Wise, personal communication). 2
We have developed an accurate method of tender- ness classification (Shackelford et al., 1997a,b). Because tenderness classification requires that a 12th-rib cross-section be removed from each carcass, it provides an easy opportunity to also assess carcass yield traits by image analysis of the cross-section. Thus, the present experiment was conducted to determine whether image analysis of the 12th-rib cross-section used for tenderness classification could accurately evaluate carcass cutability, longissimus area, and subprimal cut weights.