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Carcass length is a poor predictor of the number of boneless chops from a pork loin
The objective was to determine the predictive ability of pork carcass length on the number of boneless loin chops from a loin. Barrows and gilts (N=1238) were raised under commercial conditions and marketed when the average pig weight in a pen reached 138 kg. Pigs were slaughtered over 7 weeks in a commercial processing facility. Carcass length was measured on the left side of each carcass from the anterior of the aitch bone to the anterior of the first rib at 1 d postmortem. Carcasses were fabricated and boneless Canadian back loins (IMPS #414) were vacuum-packaged and transported to the University of Illinois Meat Science Laboratory. Loins were stored at 40C for 14 d. At the end of the aging period loins were weighed, measured for stretched length (stretched to maximum length without distortion), compressed length (compressed to minimum length without distortion) and sliced into 2.54 cm chops using a Treif Puma slicer. Complete boneless chops were counted and ends and incomplete chops were weighed. Carcass length varied from a minimum of 78.2 cm to a maximum of 96.5 cm. Chops yielded from boneless loins varied from a minimum of 13 chops 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 was determined for carcass length, boneless loin weight, stretched loin length, and compressed loin length. Carcass length explained 15% (P<0.0001) of the variation in the number of boneless loin chops. Loin weight explained 33% (P<0.0001) of the variation in the number of boneless loin chops. Stretched loin length explained 9% (P<0.0001) of the variation in the number of boneless loin chops. Compressed loin length explained 28% (P<0.0001) of the variation in the number of boneless loin chops. Multiple linear regression was used to determine a predictive equation for the number of boneless loin chops using stepwise selection option of all independent variables. The combination of loin weight and compressed loin length was able to explain 39.3% (P < 0.0001; C(p) = 12.399) of the variation in the number of boneless 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 boneless chops generated from a pork loin.