BREED COMPARISON OF THE FATTY-ACID COMPOSITION OF MUSCLE PHOSPHOLIPIDS IN JERSEY AND LIMOUSIN CATTLE

We investigated the fatty acid composition of the phospholipid fractio n of the shoulder muscle (triceps brachii) from Jersey and Limousin ye arling steers, yearling heifers, and nonlactating cows. The aim was to study breed, sex, and age differences. Significant breed differences in same individual fatty acids were apparent between Jersey and Limous in cows. Limousin cows had more palmitate, vaccenate, arachidonate, an d less gamma-linolenate and eicosapentanoate than Jersey cows. Age dif ferences were significant: proportions of palmitate, stearate, and ole ate decreased and linoleate, arachidonate, and total polyunsaturates i ncreased. with age. Most of the breed x age interactions were not sign ificant. Also, phospholipids of Jersey and Limousin cows did not diffe r in total saturated, monounsaturated, and polyunsaturated fatty acids . Yearling data revealed significant sex differences in most of the fa tty acids, including total monounsaturates and polyunsaturates. Yearli ng steers had more myristate, palmitoleate, stearate, and total monoun saturates and less linoleate, arachidonate, eicosapentanoate, and tota l polyunsaturates than heifers. Breed differences were also significan t: Limousin yearlings had more dihomogamma-linolenate and erucate and less eicosapentanoate and nervonate than their Jersey counterparts. Th e sex x breed interaction was not significant for most of the fatty ac ids. These results imply that breed, age, and sex are important factor s that influence the fatty acid composition of muscle phospholipids in cattle.