Breed and sex differences among equally mature sheep and goats 5. Lipid in dry tissue

Abstract

Males and females from Soay, Welsh Mountain, Southdown, Finnish Landrace, Jacob, Wiltshire Horn and Oxford Down sheep breeds and a breed of feral goats were slaughtered when proportionately 0-40, 0-52 0-64 or 0-76 of mature live weight. Lipid concentrations in dried tissue were obtained for perirenal fat, omental plus mesenteric fat, subcutaneous fat, carcass muscle plus associated intermuscular fat, carcass bone and offal (pelt, head, feet and organs). Lipid varied from 260 g/kg dry matter (DM) for bone to 968 g/kg for perirenal fat.As animals matured, lipid concentration increased in the dry matter of all tissues except bone, most rapidly in offal and least in intra-abdominal fat. The increases were highly correlated with the associated increases in proportion of dissected fat.Breeds differed significantly in lipid concentration in the DM of all tissues examined. Breeds with a high lipid concentration in DM of one tissue usually had high concentrations in all other tissues. The Oxford Down had the highest concentration, and the Soay and feral goat the lowest. Males had slightly lower concentrations in all tissues except internal fat.As breed size increased, mean lipid concentration (at the same stage of maturity) also increased in the DM of all tissues except bone. These breed regressions were attributed to the sampling of breeds, the smallest breeds being the exceptionally lean Soay and feral goat. Among the domesticated breeds, there were no signficant trends with breed size. , " .Lipid content of tissues t Present address:

Common factors method to predict the carcass composition tissue in kid goats

“…In the estimate of the proportion of muscle, HCW explained a small reduction of this variation, but there was no bias, showing no differences between different breed groups and genders in the estimate of muscle composition in the carcass, agreeing with the findings of Taylor et al (1989).…”

“…When compared with the same age and weight, females should have higher fat content in carcass (Taylor et al, 1989), reflecting their greater maturity, which was not found in this experiment by the low weight of the carcasses assessed.…”

“…Moreover, the bias can result from differences in the degree of maturity between animals of different sex within the same breed group and among breeds that present differences in the carcass composition at the same weight (Taylor et al, 1989) which explains the finding in this experiment, since the animals were at different ages at slaughter.…”

“…According to Taylor et al (1989), within a given breed, females have a higher fat content in carcass than males at same weight and the same age; this difference reflects the greater maturity of the females rather than the different fat deposition rate between the sexes. Moreover, the bias can result from differences in the degree of maturity between animals of different sex within the same breed group and among breeds that present differences in the carcass composition at the same weight (Taylor et al, 1989) which explains the finding in this experiment, since the animals were at different ages at slaughter.…”

Relationship of body condition score and live weight with body composition in mature Churra ewes

“…On the other hand, it is accepted that individual breeds have a distinctly different distribution of fat within the body (Taylor et al, 1989) and relationships derived from studies in one breed cannot be applied with confidence to others.…”