Breed and sex differences in equally mature sheep and goats 2. Body components at slaughter

Abstract

ABSTRACTAnimals from Soay, Welsh Mountain, Southdown, Finnish Landrace, Jacob, Wiltshire Horn and Oxford Down sheep breeds and a breed of feral goats were slaughtered when 0·40, 0·52, 0·64 or 0·76 of mature body weight. The effects of stage of maturity, breed and sex were examined in the following traits: gut content as a proportion of slaughter weight; blood, omental plus mesenteric fat, perirenal fat, alimentary tract, ‘remainder’ of non-carcass parts and hot carcass, each as a proportion of fleece-free empty body weight; also shoulder, rib, loin and gigot joints and their commercially higher-valued (prime) and lower-valued cuts, each as a proportion of carcass weight.As a proportion, gut content declined as animals matured, as also did blood, alimentary tract, ‘remainder’, prime shoulder, shank and prime gigot. Increasing proportions were internal fat depots, the hot carcass, rib, loin and gigot flank. Males accumulated significantly less internal fat and more shoulder than females.When equally mature in live weight, males had proportions that were significantly lower for perirenal fat, rib and gigot and higher for shoulder and pelt plus head, feet and organs.There were significant inter-breed regressions on mature body weight. The proportion of blood, alimentary tract, pelt plus head, feet and organs, and prime gigot declined with breed size, while hot carcass, brisket, rib and loin proportions increased. These regressions were attributed to a non-random sample of breeds. The small Soay breed had proportions of internal fat and hot carcass which were well below average, and higher proportions of blood, alimentary tract and ‘remainder’. Soay sheep also had a higher proportion of commercially higher-valued cuts in the carcass. In contrast, the large Oxford Down breed had low proportions of non-carcass components (except alimentary tract) and high proportions of lower-priced cuts and prime rib. Feral goats had a greater, and Southdown sheep a smaller, proportion of gut content than other breeds.