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


     

J. Anim Sci. 1981. 53:1383-1390.
© 1981 American Society of Animal Science
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 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 Google Scholar
Google Scholar
Right arrow Articles by Lyle, R. R.
Right arrow Articles by Backus, W. R.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Lyle, R. R.
Right arrow Articles by Backus, W. R.

Ruminal Characteristics in Steers as Affected by Adaptation from Forage to All-Concentrate Diets1

R. R. Lyle2, R. R. Johnson3, J. V. Wilhite and W. R. Backus3

University of Tennessee, Knoxville 37901

Abstract

Changes in ruminal pH, VFA and ciliate protozoa concentrations were observed as steers were adapted from all-forage to all-grain diets. In trials 1, 2 and 3, four, 47 and eight steers were adapted for 15-, 21- and 28-day periods, respectively, to all-concentrate diets composed of either whole shelled corn or various proportions of whole shelled and whole wheat plus supplement. During trial 1, total VFA concentration and molar proportions of isoacids did not change (P>.05). Acetate decreased (P<.05) from 74 moles/100 moles on day 0 to 50 moles/100 moles on day 12, while propionate increased (P<.05) from 15 to 24 moles/100 moles over the same period. Butyrate proportions increased (P<.05) from 9 to 30 moles/100 moles by day 9 and remained high throughout the trial. Ruminal pH was decreased (P<.05) only on day 15, while protozoa numbers were increased (P<.05) on days 6 and 9. In trial 2, total VFA concentration and the molar proportion of propionate were increased (P<.05) and acetate was decreased (P<.05) on days 7 and 21. Butyrate proportions were decreased (P< .05) on day 21. Valerate and isoacid proportions did not change (P>.05) during the trial and protozoa numbers were decreased (P<.05) on day 21. In trial 3, total VFA concentration tended to increase (P<.05) throughout the 28-day period. Molar proportions of acetate and propionate were decreased and increased, respectively, through day 14, after which values stabilized. Molar proportions of butyrate did not change (P<.05), while molar proportions of valerate increased (P<.05) through day 14. Molar proportions of isoacids were increased (P<.05) on day 5. Ruminal pH decreased through day 9 and stabilized thereafter. Rumen protozoa essentially disappeared by day 14. In both trials 2 and 3, molar proportions of acetate and propionate were approximately equal (44 to 46%) on day 21.

Footnotes

1 Supported in part by a grant-in-aid from Domain Industries, New Richmond, WI.

2 Present Address: Anim. Sci. Dept., Iowa State Univ., Ames 50011.

3 Dept. of Anim. Sci.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1981 by the American Society of Animal Science.