[Effects of a duodenal infusion of rapeseed oil in cows in full lactation. 1. Food intake, production and composition of milk, content of circulating metabolites].

Rape-oil was continuously infused (1.1 kg/d) during at least 3 weeks in 9 cows after the second month of lactation. Oil-free dry matter intake was decreased (-2.6 kg/d) as well as milk protein content (-2.7 g/l). A loss of empty body weight occurred during oil infusion. Preprandial blood glucose tended to decrease, whereas 3-OH-butyrate and non-esterified fatty acids (NEFA) tended to increase. Post-prandial NEFA, and NEFA after isoproterenol injection, were increased, as well as mammary apparent extraction of blood triglycerides.