The use of grass in cattle's diet improves the composition of lipid fraction of its meat. Indeed, animals raised on pasture provide meat with lower lipid content and higher proportions of 18:3 n-3, EPA, DHA and CLA, fatty acids known for their beneficial properties for human health, compared to meat from animals finished with corn silage or concentrate. Grass silage has a slightly lower impact on the n-3 polyunsaturated fatty acid (PUFA) content of bovine muscles than fresh grass. Supplementing grazing cattle with concentrate or finishing them with corn silage or concentrate in a through after a grazing period leads to a higher fat content and a lower n-3 PUFA content in meat than cattle finished on pasture. The antioxidants present in grass protect the n-3 PUFA of meat from oxidation. A 100 g portion of beef (rib eye) contributes relatively little to the total fat and fatty acid intake (less than 6% of the various Recommended Dietary Intakes). The intake of n-3 PUFA from meat from animals finished on pasture is twice as high as from meat from animals finished at the trough.(c) 2022 Societe francaise de nutrition.