Procedures for evaluating pork carcass and cut composition

Five studies were completed to investigate various production and evaluation procedures related to pork carcass composition and meat quality. A comparison of market hog characteristics of pigs selected by feeder pig frame size or current USDA feeder pig standards was made. In general, feeder pig frame size did differentiate between carcass skeletal traits (i.e., carcass length, radius length). However, frame sizing did not improve on current feeder pig grades in discriminating between carcass composition characteristics. Liquid scintillation of potassium-40 was used to estimate pork carcass composition of 124 boars barrows and gilts, ranging from 23 to 114 kg live weight. Pigs were counted live, slaughtered and one side of the carcass was counted. The side was then ground and sampled for percent protein, fat and moisture. Carcass weight and 40K determined potassium of the carcass explain more of the variation in carcass composition than live animal traits. Carcass measurements were used to determine value and percentages of fat standardized lean, protein, fat and moisture in the carcass using 265 barrow and gilt carcasses. In a separate study, belly composition was estimated from carcass and belly parameters (n = 338). Ribbed carcasses measurements were almost always superior to unribbed carcass measurements when estimating carcass or belly composition. Tenth rib fat depth was the most useful single variable for predicting belly fat, protein, moisture and lean. Some precision and accuracy were lost when using parameters from unribbed carcasses to estimate carcass or belly composition as compared to including parameters from ribbed carcasses. The sensory and nutritive value of cooked pork center loin chops and roasts were investigated. Levels of fat cover and internal temperature did not greatly affect cholesterol content