Predicting pork loin chop yield using carcass and loin characteristics

• Published in: Journal of animal science Vol. 94; no. 11; p. 4903
• Main Authors: Wilson, K B, Overholt, M F, Hogan, E K, Schwab, C, Shull, C M, Ellis, M, Grohmann, N S, Dilger, A C, Boler, D D
• Format: Journal Article
• Language: English
• Published: Champaign Oxford University Press 01-11-2016
• Subjects: Hogs; Meat products; Meat quality; Pork; Regression analysis; Thickness measurement; Weight
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas2016-0610

The objective was to determine the predictive ability of carcass length for the number of equal-thickness chops obtained from a boneless pork loin. Longer pork carcasses are assumed to yield longer loins and, therefore, an increased number of chops. Loins were collected from pigs (1,238 total) raised under commercial conditions and marketed when the mean pig weight in a pen reached 138 kg. Pigs were slaughtered over 7 wk in a commercial facility. Carcass length was measured at 1 d postmortem on the left side of each carcass from the anterior edge of the symphysis pubis bone to the anterior edge of the first rib. Carcasses were fabricated, and boneless loins (North American Meat Processors number 414) were vacuum packaged and transported to the University of Illinois Meat Science Laboratory. Loins were stored at 4°C for 14 d. At the end of the aging period, loins were weighed, measured for stretched length (stretched to maximum length without distortion) and compressed length (compressed to minimum length without distortion), and sliced into 2.54-cm-thick chops. Boneless chops were counted and weighed. Carcass length ranged from a minimum of 78.2 cm to a maximum of 96.5 cm and the number of boneless chops ranged from a minimum of 13 to a maximum of 20 chops. Data were analyzed using the regression procedure of SAS. The dependent variable was the number of boneless chops. Coefficient of determination (R^sup 2^) was calculated for carcass length, boneless loin weight, compressed loin length, and stretched loin length. Carcass length explained 15% (P < 0.0001) of the variation in the number of loin chops. Loin weight explained 33% (P < 0.0001) of the variation in the number of loin chops. Compressed loin length and stretched loin length explained 28 and 8% (P < 0.0001), respectively, of the variation in the number of loin chops. Multiple linear regression was used to determine a predictive equation for the number of loin chops using the stepwise selection option of all independent variables. The combination of boneless loin weight, compressed loin length, 10th-rib carcass fat depth, and carcass length explained 45% of the variation (P < 0.0001; C(p) = 16.76) in the number of loin chops using a required F statistic at the SLENTRY and SLSTAY level = 0.15. Overall, carcass length is a poor predictor of the number of equal-thickness loin chops that can be derived from a boneless pork loin.