A comparison of the fatty acid composition of triacylglycerols in adipose tissue from Limousin and Jersey cattle

Abstract

The fatty acid composition of the triacylglycerol fraction of shoulder fat from Limousin and Jersey yearling heifers, yearling steers, and non-lactating cows was investigated. Significant breed differences in the degree of fatty acid saturation were apparent between Jersey and Limousin cows, but were not observed in the yearlings. Jersey cows had less saturated fatty acids than the Limousin. Jersey cows showed an increased percentage of monounsaturated fatty acids compared with the Jersey yearlings. In contrast, the level of monounsaturated fatty acids in the Limousin cows was the same as in the Limousin yearlings. The calculated indices of enzyme activities also differed between the breeds. Jersey cows had higher indices of Δ9-desaturase and elongase activities than Limousin. This was also reflected by differences in the ratios of total unsaturated and polyunsaturated to saturated fatty acids. Breed differences were also observed in the triacylglycerol fatty acid chain length. In this case, however, yearlings showed significant breed differences that were not detected in the cows. Limousin yearlings had more long chain fatty acids (C16 and C18) than the Jersey yearlings. Limousin yearlings also had a higher elongase activity index than their Jersey counterparts. Thus, breed and age affect the fatty acid composition in these cattle.