A Review of Potential New Methods of On-Line Pork Carcass Evaluation

On-line techniques for estimating carcass composition and value with potential for eventual application in the packing industry must be accurate, rapid, dependable in a plant environment and cost-efficient. Several potential technologies are discussed and data are presented to establish the relative accuracy of real-time ultrasound imaging, electromagnetic scanning and optical electronic fat-lean probes. Market-weight barrows and gilts were subjected to ultrasound image analysis prior to slaughter. Carcasses were evaluated for composition using electromagnetic scanning, ultrasound image analysis, optical probe analysis and direct measurement of loin muscle area and fat depth with a dot grid and ruler. Carcasses were fabricated into standard U.S. primal cuts and each cut was dissected into lean, fat, bone and skin. Multiple linear regression analyses to predict weight of total dissected carcass lean revealed that the electronic signal from the electromagnetic scanner, carcass length and temperature combined gave an R2of .89 (RSD 1.74). Carcass ultrasound images of fat depth and loin muscle area at the 10th rib and warm carcass weight gave an R2of .79 (RSD 2.20). The electronic probe for fat and muscle depth at the 10th rib of chilled carcasses and chilled carcass weight gave an R2of .79 (RSD 2.19). The R2is .81 (RSD 2.07) when actual loin muscle area and fat depth were determined by direct measurement in ribbed carcasses and combined with carcass weight.