Simulated instrument augmentation of USDA yield grade application to beef carcasses

• Published in: Journal of animal science Vol. 76; no. 2; pp. 522 - 527
• Main Authors: Belk, K.E. (Colorado State University, Fort Collins.), Scanga, J.A, Tatum, J.D, Wise, J.W, Smith, G.C
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01.02.1998; American Society of Animal Science; Oxford University Press
• Subjects: ACCURACY; Adipose Tissue - anatomy & histology; ADIPOSE TISSUES; Animals; AREA; Beef; BEEF CATTLE; Biological and medical sciences; Body Composition; BODY FAT; CARCASSES; Cattle; Classification; DEPOT FAT; Food industries; Fundamental and applied biological sciences. Psychology; GRADING; Instruments; Meat - standards; Meat and meat product industries; MEAT CUTS; MEAT YIELD; Quality Control; Regression Analysis; Reproducibility of Results; SIMULATION; United States; United States Department of Agriculture; WEIGHT; United States; Performance evaluation; Instruments; Carcass; Body composition; Measuring instrument; Vertebrata; Meat animals; Mammalia; Beef cattle; Artiodactyla; Measurement method; Ungulata; Comparative study
• ISSN: 0021-8812; 1525-3163; 0021-8812
• DOI: 10.2527/1998.762522x

Because no instrument technology has been shown to predict beef carcass composition better than USDA yield grades, this study was conducted to determine whether an instrument could be used to augment and improve the accuracy of USDA yield grade placement. Adjusted preliminary yield grade (PYG), ribeye area (REA), estimated percentage of kidney, pelvic, and heart fat (KPH), hot carcass weight (HCW), and USDA yield grade (called and computed) were determined by five on-line USDA graders and two USDA grading supervisors for beef carcasses (n = 550) selected randomly in a commercial beef packing plant. Data were compared (2,737 comparisons) to Gold Standard yield grades and yield grade factors determined by an expert panel of carcass evaluators (unrestrained in access or time to evaluate carcasses). On-line USDA grader PYG were closely related (mean absolute error of .15 +/- .14 yield grade units; r = .91), and on-line REA and KPH were nominally related (mean absolute error of .51 +/- .35, .06 +/- .07 yield grade units and r = .48 and .66, respectively), to Gold Standard yield grade factors. On-line USDA graders determined adjusted PYG effectively, but they may require instrument assistance to evaluate carcass muscling traits and perform time-sensitive computations. To explain why instrument technology may not estimate beef carcass fatness as accurately as USDA yield grades, the absolute mean difference between Gold Standard measured PYG and adjusted PYG were compared. Only 5.6% of the sample population required no PYG adjustment, 94.4% required some adjustment, and 11.0% required over a .5 yield grade unit adjustment. Yield grades for beef carcasses, called by the USDA graders and supervisors at chain speeds, resulted in greater accuracy (absolute mean error of .24 +/- .43 yield grade units; r = .82) than when yield grades were computed for carcasses using the yield grade factors determined by on-line USDA graders and supervisors at chain speeds