American Society of Animal Science and American Dairy Science Association
Abstract
Subcutaneous adipose tissues were biopsied in 67 Jersey, Limousin and Jersey x Limousin calves at the age of 9-10 months.All calves were grass-fed in a single management group and biopsied from the same anatomical site. Triacylglycerol fatty acids were extracted and analysed by gas-liquid chromatography. Genetic effects of heterosis, additive and maternal variances were estimated to investigate the mode of inheritance of fatty acids, Sex and genotype differences were also examined. Heifer calves had significantly higher proportions of palmitoleate, total monounsaturated fatty acids, desaturase enzyme activity index and lower stearate than bull calves. Genotype differences were observed:Limousin calves had the highest proportions of palmitate and total saturated fatty acids, while Jersey calves had the most palmitoleate and desaturase enzyme activity index. The mode of inheritance of palmitate, stearate, desaturase and elongase enzyme indices was by dominance. Myristate, palmitate and total saturated fatty acids showed significant additive genetic effect. The study showed that triacylglycerol fatty acids are heritable. Hetero-sis can also be exploited in reducing the percentage of saturated fatty acids in beef by crossbreeding Limousin and Jersey cattle
