{"content":[{"text":"BEEF YIELD GRADING: History, Issues, and Opportunities","bbox":{"left":0.272386,"top":0.093788,"width":0.45526500000000003,"height":0.015151999999999999}},{"text":"Ty E. Lawrence, Ph.D., Professor of Animal Science, West Texas A&M University, Canyon","bbox":{"left":0.152392,"top":0.123813,"width":0.695216,"height":0.015151999999999999}},{"text":"Beef grades have been in use in the United States for almost 100 years. They were \n developed to assist in uniform marketing of dressed beef across the country. Grades were \n initially based solely upon quality, but were amended 50 years ago to assess carcass lean meat \n yield as well.","bbox":{"left":0.117686,"top":0.183965,"width":0.751839,"height":0.07500000000000001}},{"text":"Beef yield grading history","bbox":{"left":0.117686,"top":0.273965,"width":0.20720299999999997,"height":0.015151999999999999}},{"text":"The United States beef yield grade arose from industry interest in lean meat yield \n measurement beginning in the 1950s. Landmark data from which the yield grade is derived was \n presented at the American Society of Animal Production meetings in Chicago in 1960 and \n consisted of 162 beef carcasses representative of the period (Murphey et al., 1960). Those data \n evaluated 17 independent variables of fat content, weight, muscle content, maturity, or carcass \n dimensions to develop 23 multiple-linear prediction equations for predicting bone-in or boneless \n retail yield. An equation to estimate percentage boneless closely trimmed round-loin-rib-chuck \n (BCTRLRC) was derived using 12th rib fat depth, percentage kidney-pelvic-heart fat, hot carcass \n weight and ribeye area; this equation accounted for 91% of the variation in boneless retail yield. \n A second equation, the calculated yield grade, was developed as a 1-through-5 index using the \n same four carcass variables to estimate ranges of BCTRLRC. Yield grading began as a one-year \n trial in July 1962 and was put into effect on June 1, 1965.","bbox":{"left":0.117686,"top":0.303965,"width":0.7650770000000001,"height":0.23473500000000008}},{"text":"Since the industry began using the yield grade equation, much research (Abraham et al., \n 1968; Abraham et al., 1980; Reiling et al., 1992; Farrow et al., 2009) has evaluated the \n relationships of the four chosen variables to percentage boneless lean yield. Subcutaneous fat \n depth measured at the 12th rib is most closely related (r = -0.53 to -0.66) to boneless lean yield, \n followed by percentage kidney-pelvic-heart fat (r = -0.18 to -0.58), ribeye area (r = -0.18 to 0.51), \n and hot carcass weight (r = -0.03 to -0.53). These linear correlation coefficients are highly variable \n and indicate weak (r < 0.30) to moderate (r > 0.50) relationships to boneless lean yield. In \n comparison, the original data from which the yield grade equation was created was more strongly \n correlated to boneless retail yield; -0.79 for 12th rib subcutaneous fat depth and -0.63 for \n percentage kidney-pelvic-heart fat.","bbox":{"left":0.117686,"top":0.553725,"width":0.7649900000000001,"height":0.194697}},{"text":"At inception, the yield grade was determined from a single measure of 12th rib fat depth \n at a point three-quarters of the medial-lateral distance of the ribeye from the split chine bone \n (using a fat ruler or subjective assessment), ribeye cross-section area between the 12th and 13th \n ribs (using a dot grid or subjective assessment), a visual estimate of the percentage of the hot \n carcass weight represented by kidney-pelvic-heart fat and the kidney itself, and the hot carcass \n weight. By 1978, the Government Accountability Office reported to the U.S. Congress that yield \n grade needed to be assessed more accurately (Woerner & Belk, 2008). Development of an","bbox":{"left":0.117686,"top":0.76221,"width":0.765066,"height":0.13609400000000005}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}