HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Huntington, G. B. Articles by Tyrrell, H. F. Search for Related Content PubMed PubMed Citation Articles by Huntington, G. B. Articles by Tyrrell, H. F.

Net Absorption and Ruminal Concentrations of Metabolites in nonpregnant Dry Holstein Cows before and after Intraruminal Acetic Acid Infusion¹

Ruminant Nutrition Laboratory, Animal Science Institute, Agricultural Research Service, US Department of Agriculture, Beltsville, MD 20705

ABSTRACT

Objectives were to define daily patterns of net absorption of various nutrients and to assess effects of intraruminal infusion of acetic acid on concentrations of ruminal fluid and net absorption of various metabolites. These characteristics were measured in three nonpregnant, dry Holstein cows (491 kg) at hourly intervals for 24 h before and after 5 days of intraruminal infusion of acetic acid to provide energy equal to 10% of daily intake of metabolizable energy. Cows were fed a completely mixed, 60% corn silage, 40% grain supplement diet at maintenance intake; daily rations were split into two feedings. Net rates of absorption were greatest after feeding and least during early morning. Net absorption of all metabolites measured was similar for the two daily feeding intervals, indicating daily net absorption could be calculated from either feeding interval. Intraruminal infusion of acetic acid caused increased ruminal and plasma concentrations of acetate, increased net absorption of acetate, and almost a twofold increased loss of urea-nitrogen from plasma to the gut. Sixty-nine percent of acetic acid infused was accounted for by increased net absorption of acetate. Ruminal fluid concentrations and net absorption of other volatile fatty acids were not affected by infusion of acetic acid. Net absorptions of ammonia-nitrogen, L-lactate, and glucose likewise were not affected. Net absorption of volatile fatty acid and L-lactate was 43% of daily intake of metabolizable energy.

¹ Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the US Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.

This article has been cited by other articles:

				J. C. Resende Junior, M. N. Pereira, H. Boer, and S. Tamminga Comparison of techniques to determine the clearance of ruminal volatile fatty acids. J Dairy Sci, August 1, 2006; 89(8): 3096 - 3106. [Abstract] [Full Text] [PDF]