FATTY-ACIDS IN THE SUBCUTANEOUS ADIPOSE-TISSUE OF INTENSIVELY FED SA MUTTON MERINO AND DORPER WETHERS

Recent ambiguity about the role of animal fat in causing coronary hear t disease, coupled with the controversy regarding the effect of variou s levels of energy nutrition on ruminant depot fats, prompted an inves tigation into the influence of high-energy nutrition, breed and slaugh ter weight on the fatty acid profiles of ruminants. Two isonitrogenous and isomineral diets containing 11.76 MJ ME/kg DM and 10.18 MJ ME/kg DM were fed to Dorper and SA Mutton Merino wethers of +/- 20 kg to 37 and 43 kg live weight. Subcutaneous fat samples and feed samples were collected for fatty acid analysis. Treatment significantly affected th e subcutaneous fatty acid profiles of wethers, which includes C15:0, C 16:0, C17.0, C17:1, C18:0, C18:1, C18:2 and C18:3. Treatment also infl uenced the concentration of saturated and unsaturated fatty acids in t he subcutaneous adipose tissue as well as the concentration of trans-f atty acids. The results obtained suggest that dietary energy levels ma y significantly affect the fatty acids in the subcutaneous fat of weth ers. Breed differences, after correcting for carcass fatness, occurred in C16:0.