| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Unité de Recherches sur les Herbivores, Institut National de la Recherche Agronomique, Theix, 63122 Saint-Genès-Champanelle, France.
Corresponding author: M. Doreau; e-mail: doreau{at}clermont.inra.fr.
The effect of linseed oil (LSO) supplementation on total-tract and ruminal nutrient digestibility, N metabolism, and ruminal fluid characteristics was investigated in dairy cows fed diets containing different forage to concentrate ratios (F:C). The experimental design was a 4 x 4 Latin square with 2 x 2 factorial arrangement of treatments. Four lactating Holstein cows were fed a forage-rich diet without LSO (F; F:C = 65:35, dry matter basis), a forage-rich diet with LSO (FO; F:C = 65:32, 3% LSO), a concentrate-rich diet without LSO (C; F:C = 35:65), or a concentrate-rich diet with LSO (CO; F:C = 35:62, 3% LSO). Total-tract digestibility of DM and OM was greater with supplemental LSO. A tendency for greater total-tract digestibility of NDF and ADF also was observed in cows fed LSO. Ruminal digestibility of NDF or ADF decreased when CO was fed compared with C. In contrast, feeding FO increased NDF or ADF digestibility compared with F. Although ruminal starch digestion was nearly complete with all diets, digestibility was greater when cows were fed C or CO compared with F or FO. Bacterial N flow to the duodenum decreased when FO was fed compared with F. In contrast, feeding CO increased bacterial-N flow compared with C. Neither F:C nor LSO supplementation affected ruminal pH or total VFA concentration in ruminal fluid. However, molar proportion of propionate was greater with C or CO compared with F or FO and increased with LSO supplementation regardless of F:C. Molar proportion of n-butyrate decreased with LSO supplementation. Total protozoal numbers in ruminal fluid decreased markedly only when CO was fed. Overall, data show that feeding LSO had no negative effects on total-tract digestion in dairy cows but may decrease ruminal fiber digestibility when fed with high-concentrate diets. The widely spread idea that LSO decreases digestibility, arising from studies with sheep, did not seem to apply to lactating cows fed 3% LSO.
Key Words: dairy cow • forage to concentrate ratio • linseed oil • ruminal digestion
Abbreviation key: C = concentrate-rich diet without LSO, CLA = conjugated linoleic acid, CO = concentrate-rich diet with 3% LSO, F = forage-rich diet without LSO, FO = forage-rich diet with 3% LSO, F:C = forage to concentrate ratio, LAB = liquid associated bacteria, LSO = linseed oil, PPB = purine and pyrimidine bases, SAB = solid-adherent bacteria
This article has been cited by other articles:
|
|
 |
|
  F. Glasser, A. Ferlay, M. Doreau, P. Schmidely, D. Sauvant, and Y. Chilliard Long-Chain Fatty Acid Metabolism in Dairy Cows: A Meta-Analysis of Milk Fatty Acid Yield in Relation to Duodenal Flows and De Novo Synthesis J Dairy Sci, July 1, 2008; 91(7): 2771 - 2785. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Firkins, Z. Yu, and M. Morrison Ruminal Nitrogen Metabolism: Perspectives for Integration of Microbiology and Nutrition for Dairy J Dairy Sci, June 1, 2007; 90(13_suppl): E1 - E16. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. C. Kim, A. T. Adesogan, L. Badinga, and C. R. Staples Effects of dietary n-6:n-3 fatty acid ratio on feed intake, digestibility, and fatty acid profiles of the ruminal contents, liver, and muscle of growing lambs J Anim Sci, March 1, 2007; 85(3): 706 - 716. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Mach, M. Devant, I. Diaz, M. Font-Furnols, M. A. Oliver, J. A. Garcia, and A. Bach Increasing the amount of n-3 fatty acid in meat from young Holstein bulls through nutrition J Anim Sci, November 1, 2006; 84(11): 3039 - 3048. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Vlaeminck, V. Fievez, S. Tamminga, R. J. Dewhurst, A. van Vuuren, D. De Brabander, and D. Demeyer Milk odd- and branched-chain Fatty acids in relation to the rumen fermentation pattern. J Dairy Sci, October 1, 2006; 89(10): 3954 - 3964. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Loor, A. Ferlay, A. Ollier, M. Doreau, and Y. Chilliard Relationship Among Trans and Conjugated Fatty Acids and Bovine Milk Fat Yield Due to Dietary Concentrate and Linseed Oil J Dairy Sci, February 1, 2005; 88(2): 726 - 740. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Loor, K. Ueda, A. Ferlay, Y. Chilliard, and M. Doreau Biohydrogenation, Duodenal Flow, and Intestinal Digestibility of Trans Fatty Acids and Conjugated Linoleic Acids in Response to Dietary Forage:Concentrate Ratio and Linseed Oil in Dairy Cows J Dairy Sci, August 1, 2004; 87(8): 2472 - 2485. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
