Effect of Starch on the Bioavailability of Glutamine and Leucine in the Dairy Cow

¹ Department of Ruminant Nutrition, Dienst Landbouwkundig Onderzoek, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands
² Department of Nutrition of Pigs and Poultry, Dienst Landbouwkundig Onderzoek, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands

This experiment was designed to quantify changes in utilization of Gln and Leu by the gut wall as a result of changes in the starch supply to the duodenum. Four dairy cows fitted with cannulas in the rumen and the distal duodenum were adapted for 3 wk to starch infusion, either into the rumen (600 g/d of flaked maize) or into the duodenum (300 g/d of flaked maize plus 300 g/d of maize meal), in a 2 x 2 crossover design. Absorption and elimination kinetics and the relative bioavailability of Gln and Leu were measured during wk 4 and 5. After infusion of 50 g of Gln or 10 g of Leu into the duodenum or jugular vein, blood samples were taken from the jugular vein at 0.5-h intervals up to 4 h after infusion. Concentrations of Gln and Leu in plasma fitted best to an open, one-compartment model (duodenal infusion) or to an open, two-compartment model (i.v. infusion). Both amino acids were rapidly absorbed; half-life times were less than 20 min. The amount of Gln trapped in the splanchnic bed was higher than the amount of Leu trapped in the splanchnic bed. Site of starch infusion did not affect the relative bioavailability of amino acids.

Key Words: glutamine • leucine • absorption kinetics • starch

Submitted on January 29, 1996
Accepted on April 8, 1997

This article has been cited by other articles:

				M. Oba, R. L. Baldwin VI, and B. J. Bequette Oxidation of glucose, glutamate, and glutamine by isolated ovine enterocytes in vitro is decreased by the presence of other metabolic fuels J Anim Sci, February 1, 2004; 82(2): 479 - 486. [Abstract] [Full Text] [PDF]