The maturity stage of the grass affects milk fatty acids of cows grazing a mountain grassland

International audience; We aimed to quantify the effect of the growth stage of a mountain grassland pasture on the fatty acid (FA) composition of grass and milk. In June (growth) and October (regrowth), a mountain pasture was continuously grazed by six dairy cows in a strip grazing system. During June, the grass C18:3n-3 content decreased while C16:0, c9-C18:1 and C18:2n-6 content increased. During October, the grass FA composition was similar to that observed in the first part of June. During June, milk saturated FA (SFA) content increased while the sum of the trans FA and polyunsaturated FA (PUFA) content decreased, mainly due to the decrease in C18:3n-3 and c9t11-CLA percentages. At the …