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Virginia Tech

Free and peptide amino acid fluxes across the mesenteric and non-mesenteric viscera of sheep and calves

Abstract

dc:description.abstract

The flux of free and peptide amino acids across the stomach and intestinal tissues was quantified using sheep and calves maintained in "steady state” conditions by feeding at hourly intervals. Crossbred wethers and Holstein steers were surgically cannulated in the abdominal aorta, mesenteric vein and portal vein. All animals were fed an orchardgrass, corn, SBM-based diet. The steers received three abomasal infusions; a control solution, and an amino acid mixture simulating casein and casein each at a rate equivalent to 25% of daily crude protein intake. Nutrient fluxes from the mesenteric and portal-drained viscera were measured; non-mesenteric flux was calculated as the difference between portal flux and mesenteric flux. Results of this study support the concept that free amino acids are absorbed by the small intestine and not by the stomach. The flux of peptide amino acids across the portal-drained-viscera indicate that a major portion of the amino acids which are absorbed by cattle and sheep are absorbed in the form of peptides from the stomach. The observation that large quantities of peptide amino acids are absorbed from the stomach is unique and it is expected that this most important discovery will revolutionize the feeding of ruminants.

Degree

thesis:*
Name thesis:degree_name
Ph. D.
Level thesis:degree_level
doctoral
Discipline thesis:degree_discipline
Animal Science
Department dc:contributor.department
Animal Science
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
1992

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • DiRienzo, Douglas B.
Chair dc:contributor.committeechair
  • Webb, Kenneth E. Jr.
Committee members dc:contributor.committeemember
  • Herbein, Joseph H. Jr.
  • Kornegay, Ervin T.
  • Akers, Robert Michael
  • McGrath, Charles J.
  • Thye, Forrest W.

Rights

dc:rights
Statement dc:rights
  • In Copyright
Language dc:language.iso
en

Identifiers

dc:identifier.*
Dc Identifier Other
etd-10132005-152549
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/39841

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
related terms
citation

DiRienzo, Douglas B.. Free and peptide amino acid fluxes across the mesenteric and non-mesenteric viscera of sheep and calves. doctoral thesis, Virginia Tech, 1992. http://hdl.handle.net/10919/39841