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 Google Scholar Google Scholar Articles by Alexander, C. L. Articles by Meyer, R. M. Search for Related Content PubMed PubMed Citation Articles by Alexander, C. L. Articles by Meyer, R. M.

Techniques to Determine Rate of Metabolism of C¹⁴-Labeled Alfalfa in the Bovine Rumen¹

Department of Dairy Science, Kansas State University, Manhattan

ABSTRACT

In an earlier experiment, it was not possible to predict with certainty the rate of metabolism of one feeding of C¹⁴-labeled alfalfa hay, because rumen volatile fatty acids (VFA) arising from the metabolism of unlabeled hay from previous or subsequent feedings diluted specific activity (SA) of VFA arising from the single feeding of labeled hay. In this study the extent of dilution of SA of rumen VFA by VFA arising from previous or subsequent feedings was determined by fasting a cow after a single feeding of C¹⁴-labeled alfalfa or by emptying her rumen of all digesta, replenishing the rumen with strained rumen fluid before feeding C¹⁴-labeled alfalfa, then fasting the cow. In both instances, SA of rumen VFA increased rapidly after feeding, reached a peak between 5 and 9 hr, then declined. The decline was less rapid than in the earlier experiment when the animals were fed hay at 12-hr intervals.

On the basis of total activity of rumen VFA, the most active rumen metabolism of C¹⁴-labeled alfalfa occurred between 4 and 8 hr. The most active metabolism of cellulose occurred during the first 12 hr, with little after 36 hr.

¹ Contribution No. 334, Department of Dairy Science, Kansas Agricultural Experiment Station, Manhattan, Kansas.