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 heart disease, coupled with the controversy regarding the effect of various levels of energy nutrition on ruminant depot fats, prompted an investigation into the influence of high-energy nutrition, breed and slaughter 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 the subcutaneous fatty acid profiles of wethers, which includes C15:0, C16:0, C17.0, C17:1, C18:0, C18:1, C18:2 and C18:3. Treatment also influenced the concentration of saturated and unsaturated fatty acids in the subcutaneous adipose tissue as well as the concentration of trans-fatty acids. The results obtained suggest that dietary energy levels may significantly affect the fatty acids in the subcutaneous fat of wethers. Breed differences, after correcting for carcass fatness, occurred in C16:0.