Influence of Systematic Biases Associated with Genotype and Sex on Prediction of Lean Mass and Carcass Value in U.S. Pigs

Purdue University 1997 Swine Research Report. Much work has been done on developing equations for estimating fat-free lean mass and carcass value in pigs (Akridge et al., 1992; and Boland et al., 1995). However, most equations currently in use have not been evaluated for the extent to which they account for genotype and sex differences in carcass composition. Packers produce pork products from pigs of diverse genotypic backgrounds and different sexes. Therefore, any realistic attempt to develop an unbiased evaluation system should account for a high percentage of the genotype and sex differences. Equations for predicting lean mass and carcass value use a variety of evaluation technologies. These include rulers, optical probes, ultrasonic imaging, and electromagnetic scanning. Regression equations are used to convert measurement readings from these technologies into lean mass and carcass value (Forrest et al., 1989). The objective of this study was to examine the influence of biases associated with genotype and sex on prediction of fat free lean mass and carcass value in pigs, and measures that can be put in place to minimize biases.