We present a novel study of the effect of bta-miR-33a on lipid metabolism in bovine mammary epithelial cells (BMECs). The correlation between bta-miR-33a and target gene ELOVL6 is also verified by a luciferase reporter assay. We show that bta-miR-33a directly inhibits the expression of ELOVL6 in BMECs, altering the mRNA expression of relative genes. This suggest that bta-miR-33a regulates lipid metabolism by targeting ELOVL6, which might be a potential molecular marker of milk fat composition.

In Spain, young bulls are slaughtered about 14 months. After slaughter, the carcasses remain in the slaughterhouse for less than 7 d. The present work collects this information and makes an attempt to analyse the response of the meat during the first 7 d of maturation to the oxidation of the fatty acids. Natural antioxidants in beef ensure fatty acid stability during first 7 d postmortem. Beef from pasture-fed meat includes a higher natural antioxidant content than grain-fed meat.

The research was carried out on cows fed with a conventional or green fodder diet in order to determine the physicochemical characteristics and mineral content in milk. The data show similar results except for the fat content, which is higher in milk coming from cows fed with hydroponic barley. Minerals were in the range reported elsewhere. The hydroponic fodder system seems to be an ideal solution in places where it is not possible to grow fresh fodder or where pasture grazing is nonexistent.

The quantity and quality of beef can be increased through crossing beef bulls with dairy cows. This experiment was conducted to compare carcass traits in young bulls and steers, produced by crossing Holstein-Friesian cows with Hereford bulls. Meat from steers had higher intramuscular fat content and was tenderer and juicier than meat from bulls. Steer IMF was characterized by a more desirable n-6 / n-3 PUFA ratio. Beef from steers is a good choice for consumers who appreciate high-quality meat.