JDS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Journal of Dairy Science Vol. 77 No. 2 552-559
© 1994 by American Dairy Science Association ®
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 Robinson, P. H.
Right arrow Articles by Kennelly, J. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Robinson, P. H.
Right arrow Articles by Kennelly, J. J.

Forestomach and Whole Tract Digestion in Lactating Dairy Cows Fed Canola Meal Treated with Variable Levels of Acetic Acid

P. H. Robinson 1, G. R. Khorasani 1, and J. J. Kennelly 1

1 Department of Animal Science, University of Alberta, Edmonton, AB, Canada T6G 2P5

Five Holstein cows in midlactation were fed four isonitrogenous (mean 2.76% N) mixed diets containing untreated canola meal or replaced with canola meal treated with 0, 33, 67, or 100% of acetic acid in a 12-wk 4 x 4 Latin square experiment. Diets were 50%6 barley-based concentrate, 12% canola meal, 30% whole crop oat silage, and 8% alfalfa silage (DM basis). Forestomach and whole tract apparent digestibilities of DM, OM, and its components, including fiber and CP, did not differ as proportions of treated canola meal increased. Rumen pool sizes of OM, NDF, and bacterial OM, as well as total NAN and bacterial N, were not influenced by treatment, although bacterial N pool size tended to decline as treated canola meal replaced untreated. This result was consistent with a trend for reduced flow of bacterial N at the duodenum. Duodenal flow of AA protein, and its profile, was not influenced by treatment. Results suggest that low level replacement of untreated canola meal with canola meal treated with acetic acid stimulated microbial growth by providing more sustained delivery of slowly degraded true protein. However, at higher substitution, the rumen microbial pool was reduced progressively, perhaps because of a shortage of readily fermentable N. This hypothesis, although not consistent with all data, seems to be the most plausible explanation for all observations, although it is clear that differences in both digestion and duodenal flow, particularly for protein, attributable to replacement of untreated canola meal by that treated with acetic acid were moderate.

Key Words: canola meal • acetic acid • dairy cows

Submitted on July 12, 1993
Accepted on October 12, 1993




This article has been cited by other articles:


Home page
 J ANIM SCIHome page
J. C. Marini, D. G. Fox, and M. R. Murphy
Nitrogen transactions along the gastrointestinal tract of cattle: A meta-analytical approach
J Anim Sci, March 1, 2008; 86(3): 660 - 679.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1994 by the American Dairy Science Association ®.