J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wanderley, R. C.
Right arrow Articles by Fontes, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wanderley, R. C.
Right arrow Articles by Fontes, C., Jr

Journal of Animal Science, Vol 71, Issue 11 3073-3077, Copyright © 1993 by American Society of Animal Science

JOURNAL ARTICLE

Influence of microbial colonization of feed particles on determination of nitrogen degradability by in situ incubation

R. C. Wanderley, J. T. Huber, Z. Wu, M. Pessarakli and C. Fontes Jr
Department of Animal Sciences, University of Arizona, Tucson 85721.

Stable 15N isotope was used to determine the extent of microbial colonization of in situ incubation residues and the influence of colonization on estimates of ruminal degradability of feed N. In an in vitro trial, 15N:total N ratio remained unchanged after the soluble (by water, saline, or buffer solution) fraction of plant N was removed, suggesting that 15N was uniformly distributed in the soluble and insoluble N fractions. In three in situ trials, corn grain, corn husks, and alfalfa hay labeled with 15N as an internal marker were incubated in Dacron bags in the rumen of two lactating Holstein cows for 3, 6, 12, 24, 36, and 48 h. Enrichment of 15N in samples decreased with increased time of incubation for all feeds. At 48 h of incubation, 31, 71, and 65% of the residual N was microbial N for corn grain, corn husks, and alfalfa hay, respectively. Bacterial cell DM, as a percentage of residual DM, increased in a quartic manner, suggesting that microbial colonization depended on substrate availability. For 24, 36, and 48 h incubation, bacterial DM, as a percentage of total residue, averaged 10.0 +/- 1.0% for corn grain, 17.5 +/- 1.4% for corn husks, and 22.0 +/- .2% for alfalfa hay. Apparent degradability of N after 48 h of incubation was approximately 65% for corn grain and alfalfa hay and 19% for corn husks. When corrected for bacterial N, degradabilities of N in all feeds increased and the degradabilities for corn husks became similar to those for corn grain.(ABSTRACT TRUNCATED AT 250 WORDS)


This article has been cited by other articles:


Home page
 J ANIM SCIHome page
J. L. Leupp, G. P. Lardy, S. A. Soto-Navarro, M. L. Bauer, and J. S. Caton
Effects of canola seed supplementation on intake, digestion, duodenal protein supply, and microbial efficiency in steers fed forage-based diets
J Anim Sci, February 1, 2006; 84(2): 499 - 507.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1993 by the American Society of Animal Science.