Intestinal Disappearance and Mesenteric and Portal Appearance of Amino Acids in Dairy Cows Fed Ruminally Protected Methionine
Open Access
- 1 January 2001
- journal article
- Published by American Dairy Science Association in Journal of Dairy Science
- Vol. 84 (1), 194-203
- https://doi.org/10.3168/jds.s0022-0302(01)74469-4
Abstract
An experiment was conducted to compare the rates of disappearance of amino acids (AA) from the small intestine and their net appearance in the blood draining only the small intestine (mesenteric-drained viscera) and the whole gastrointestinal tract (portal-drained viscera) of cows fed a silage-based diet supplemented or not with ruminally protected Met. Five lactating dairy cows (118 ± 4 DIM) equipped with duodenal and ileal cannulae (n = 2) or a duodenal cannula only (n = 3), two of which were multicatheterized, were fed a TMR top dressed with 0 or 72 g of ruminally protected Met per day. The addition of ruminally protected Met to the diet increased the duodenal flux of Met leading to a higher apparent digestibility of Met in the small intestine. Sixty-six percent of Met from ruminally protected Met bypassed the rumen and 82% of that Met disappeared from the small intestine. Arterial plasma Met concentrations numerically increased with ruminally protected Met (45 vs. 18 μM), while total AA concentration decreased. Feeding ruminally protected Met resulted in higher concentrations of urea-N and glucose in arterial plasma. Milk production and milk composition were unaffected. The disappearance of essential AA across the small intestine was equivalent (101%) to their flux through the mesenteric-drained viscera while the portal:mesenteric-drained viscera flux ratio for each essential AA varied from 38% for Thr to 76% for Phe. The portal:mesenteric-drained viscera flux ratio for Met was 66%. These results confirm observations made with pigs and sheep.Keywords
This publication has 30 references indexed in Scilit:
- Comparison of the In Situ and In Vivo Intestinal Disappearance of Ruminally Protected MethionineJournal of Dairy Science, 2000
- A cranial mesenteric vein preparation for measurement of amino acid uptake by lambsThe Journal of Agricultural Science, 1994
- Effect of age and intake on growth hormone kinetics in dairy heifersDomestic Animal Endocrinology, 1992
- Simultaneous determination of allantoin and oxypurines in biological fluids by high-performance liquid chromatographyJournal of Chromatography B: Biomedical Sciences and Applications, 1992
- Partition of portal-drained visceral net flux in beef steersBritish Journal of Nutrition, 1988
- Glucagon, Insulin, Growth Hormone, and Glucose Concentrations in Blood Plasma of Lactating Dairy CowsJournal of Dairy Science, 1985
- Net Absorption of Glucose and Nitrogenous Compounds by Lactating Holstein CowsJournal of Dairy Science, 1984
- AUTOMATED SIMULTANEOUS DETERMINATION OF AMMONIA AND TOTAL AMINO-ACIDS IN RUMINAL FLUID AND INVITRO MEDIAJournal of Dairy Science, 1979
- The effect of formaldehyde treatment before ensiling on the digestion of wilted grass silage by sheepBritish Journal of Nutrition, 1979
- AN IMPROVED PROCEDURE FOR THE DETERMINATION OF CHROMIC OXIDE IN FEED AND FECESCanadian Journal of Animal Science, 1979