Influence of Yield Grade of Fresh Lamb Carcasses on Shrinkage and Psychrotrophic Bacteria Counts during Transport

Abstract

At origin, no differences in surface microbial counts were observed for the different yield grades or for the areas of the carcasses (leg or flank) where samples were taken. However, there were significant differences in total microbial counts on shipments from different packinghouses. Similar differences in microbial counts were reflected in the results obtained at destination. The study reported here on shrinkage of lamb carcasses with different thicknesses of external fat shows that carcasses with a thick external fat covering such as found in yield grade 4 shrank less (.65%) than carcasses with little or no external fat covering as found in yield grade 2 (.84%). A high carcass temperature at the time of loading followed by a large decrease in carcass temperature during transit resulted in the greatest amount of shrinkage in these test shipments. Some shipments had lamb carcasses with an average internal temperature of 9 C at time of loading. A high shrinkage was observed in these lamb carcasses because part of the shrinkage normally encountered in the chill room of the packinghouse was encountered during transit. Copyright © 1976. American Society of Animal Science . Copyright 1976 by American Society of Animal Science