Changes in body composition relative to weight and maturity of Australian Dorset Horn rams and wethers. 3. Fat partitioning

Abstract

ABSTRACTThe effect of castration on fat partitioning in mature animals and on the maturing patterns for fat depots relative to total body fat was examined using slaughter and dissection data from 20 Dorset Horn rams and 20 Dorset Horn wethers. Animals were slaughtered at 6 kg intervals from 18 kg live weight to maturity. Five rams and eight wethers were classified as mature.In the mature animals the partitioning of fat differed for the rams and wethers in that the rams had a lower proportion of subcutaneous fat, and higher proportion of intermuscular and mesenteric fat than the wethers. However, the proportions of total carcass dissectible fat (i.e. subcutaneous plus intermuscular fat) and of the total non-carcass depots (i.e. kidney plus channel fat, omental, scrotal and thoracic fat) did not significantly differ between rams and wethers.The maturity coefficients of individual fat depots of rams and wethers were not significantly different and six of the nine depots were average maturing relative to total body fat. The intermuscular and thoracic fat depots were early maturing (maturity coeffient q= 1·19, 2·26 respectively), and the omental depot was late maturing (q= 0·52).Comparison of the partitioning of fat in rams and wethers reflected the differences in the mature animals when made at either the mean weight or at the mean stage of maturity, as the maturing patterns of most depots were not greatly different from that of total fat.