A Further Investigation of Specific Gravity as a Measure of Pork Carcass Value

Abstract

A multiple correlation coefficient of .912 was found between the specific gravity of the lean of 23 hams and the percentages of moisture, protein and ether extract. It was found that the sampling of the meat may be an important source of error when chemical analysis is used to evaluate carcasses. Correlation coefficients of .949 and .942 were obtained between the specific gravities of the right hams and the half carcasses from which they came, using two groups of 23 and 46 carcasses respectively. A study of the associations of the parts of the ham with specific gravity indicated that the percentages of either the fat and skin or lean have a greater influence on the specific gravity of the ham than does the percentage of the bone. The densities of the fat and skin and the lean also were more closely associated with the ham density than was the density of the bone. Simple intra-breed correlation coefficients were calculated for each of eight measures of carcass leanness with specific gravity and average back fat thickness, using data from 203 carcasses. In one group of data, specific gravity was significantly more highly correlated with other measures of carcass leanness than was average back fat thickness. In the other group of data specific gravity was also more highly associated (though not significantly) with other measures of carcass leanness than was average back fat thickness. A discussion of some of the factors that have been or need to be considered in using the specific gravity technique is also included.