FATTENING PATTERNS IN CATTLE. 1. FAT PARTITION AMONG THE DEPOTS

Abstract

A trial is reported comparing half-carcass fat partitioning in 12 bulls and 12 heifers each of two breed-types: Hereford (HE) and Dairy Synthetic (DY). These animals were serially slaughtered from weaning (163 ± 15.1 (SE) days) 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. The partition of fat was investigated by examining the development of each depot relative to two independent variates (fat percent and fat weight in the side), using the allometric equation. Relative to fat percent in the side, the regression coefficients for depot fat accumulation were all homogeneous for sex, and only one coefficient (SF in the forequarter) was significantly different (P < 0.05) for breed. Relative to fat weight in a side, the regression coefficients for both breed and sex showed several significant differences. Adjusted means at constant total fat weight showed HE animals to have more SF, and less IF than DY animals. There were no significant differences in the adjusted means for sex.