FATTENING PATTERNS IN CATTLE. 2. FAT DISTRIBUTION AMONG THE WHOLESALE CUTS

Abstract
A trial is reported comparing fat distribution in carcasses from bulls and heifers of two breed-types: Hereford (HE) and Dairy Synthetic (DY). Twelve bulls and twelve heifers of each breed were grouped four to a pen at weaning (163 ± 15.1 (SE) days), and serially slaughtered from that time to approximately 16 mo of age. After slaughter, one side of each carcass was broken into eight wholesale cuts, which were separated into fat (subcutaneous fat (SF), intermuscular fat (IF), and body cavity fat (BCF)), muscle and bone. Depot fat accretion in each cut was investigated using the allometric equation with side fat weight as the independent variable. Coefficients for SF were significantly higher in the rib, chuck and flank for HE carcasses than for DY carcasses and higher in the rib and flank for heifers than for bulls. At equal total side fat, HE carcasses had significantly more SF in the brisket and in the loin than DY animals. Heifers had significantly more fat in the loin than bulls. Differences among coefficients for IF relative to total fat were minor for both breed and sex. At equal total side fat, HE carcasses had less fat distributed intermuscularly than DY carcasses and had less IF in the brisket than heifers. The results are discussed in relation to the Canadian beef grading system.