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Rumen odd and branched chain fatty acids in relation to in vitro rumen volatile fatty acid productions and dietary characteristics of incubated substrates
Author(s) -
Vlaeminck B.,
Fievez V.,
Van Laar H.,
Demeyer D.
Publication year - 2004
Publication title -
journal of animal physiology and animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 56
eISSN - 1439-0396
pISSN - 0931-2439
DOI - 10.1111/j.1439-0396.2004.00497.x
Subject(s) - rumen , propionate , butyrate , fermentation , food science , fatty acid , starch , composition (language) , biology , short chain fatty acid , biochemistry , chemistry , zoology , linguistics , philosophy
Summary A first aim of this batch in vitro experiment (21 h) was to use changes in odd and branched chain fatty acid (OBCFA) patterns to suggest shifts in microbial populations, associated with four types of incubated whole dairy cow diets. Principal component analysis suggested higher dietary starch increased the proportion of C 15:0 and C 17:0 , whereas increased neutral detergent fibre content was positively related to anteiso C 15:0 concentrations, which is in agreement with the importance of these fatty acids in respectively amylolytic and cellulolytic bacteria. A second aim of the experiment was to relate rumen volatile fatty acid proportions to OBCFA by principal component regression and to compare these relations with predictions based on diet proximate composition. The R 2 values achieved for the regressions between acetate, propionate and butyrate, and OBCFA were 79.6%, 86.6% and 84.9% respectively. Moreover, in the current study, predictions of the rumen fermentation pattern showed higher R 2 (p < 0.01) when based on OBCFA compared with proximate feed composition. If relations persist in vivo , there could be scope for milk OBCFA to predict the supply of specific rumen nutrients.