4 research outputs found
Fatty acid composition and bacterial community changes in the rumen fluid of lactating sheep fed sunflower oil plus incremental levels of marine algae
No full text13 páginas, 7 tablas,1 figura.Supplementation of ruminant diets with plant oils
and marine lipids is an effective strategy for lowering
saturated fatty acid (FA) content and increasing the
concentration of cis-9,trans-11 conjugated linoleic acid
and long-chain n-3 FA in ruminant milk. However,
changes in populations of ruminal microorganisms
associated with altered biohydrogenation of dietary
unsaturated FA are not well characterized. Twenty-five
lactating Assaf ewes were allocated at random to 1 of
5 treatments composed of dehydrated alfalfa hay and
concentrates containing no additional lipid (control),
or supplemented with 25 g of sunflower oil and 0 (SO),
8 (SOMA1), 16 (SOMA2), or 24 (SOMA3) g of marine
algae/kg of diet dry matter. On d 28 on diet, samples
of rumen fluid were collected for lipid analysis and
microbial DNA extraction. Appearance and identification
of biohydrogenation intermediates was determined
based on complementary gas chromatography and
Ag+-HPLC analysis of FA methyl esters. Total bacteria
and the Butyrivibrio group were studied in microbial
DNA by terminal RFLP analysis, and real-time PCR
was used to quantify the known Butyrivibrio bacteria
that produce trans-11 18:1 or 18:0. Dietary supplements
of sunflower oil alone or in combination with marine
algae altered the FA profile of rumen fluid, which was
associated with changes in populations of specific bacteria.
Inclusion of marine algae in diets containing sunflower
oil resulted in the accumulation of trans 18:1 and
10-O-18:0 and a marked decrease in 18:0 concentrations
in rumen fluid. At the highest levels of supplementation
(SOMA2 and SOMA3), marine algae also promoted a
shift in ruminal biohydrogenation pathways toward the
formation of trans-10 18:1 at the expense of trans-11
18:1. Changes in the concentration of biohydrogenation
intermediates were not accompanied by significant
variations in the abundance of known cultivated ruminal
bacteria capable of hydrogenating unsaturated FA. However, certain bacterial groups detected by
terminal RFLP (such as potentially uncultured Lachnospiraceae
strains or Quinella-related bacteria) exhibited
variations in their relative frequency consistent with
a potential role in one or more metabolic pathways of
biohydrogenation in the rumen.This work was supported by the Spanish Ministry
of Science and Innovation (MICINN; AGL2008-
04805-C02-02) and the Spanish National Research
Council (CSIC; 200940I034). P. G. Toral was granted a
fellowship from the CSIC (I3P Program). The authors
thank R. John Wallace and Nest McKain from the Rowett
Institute of Nutrition and Health (Aberdeen, UK),
and C. Jamie Newbold from the Institute of Biological, Environmental and Rural Sciences (Aberystwyth, UK)
for kindly providing the bacterial strains.Peer reviewe
Fatty acid composition and bacterial community changes in the rumen fluid of lactating sheep fed sunflower oil plus incremental levels of marine algae
No full text13 páginas, 7 tablas,1 figura.Supplementation of ruminant diets with plant oils
and marine lipids is an effective strategy for lowering
saturated fatty acid (FA) content and increasing the
concentration of cis-9,trans-11 conjugated linoleic acid
and long-chain n-3 FA in ruminant milk. However,
changes in populations of ruminal microorganisms
associated with altered biohydrogenation of dietary
unsaturated FA are not well characterized. Twenty-five
lactating Assaf ewes were allocated at random to 1 of
5 treatments composed of dehydrated alfalfa hay and
concentrates containing no additional lipid (control),
or supplemented with 25 g of sunflower oil and 0 (SO),
8 (SOMA1), 16 (SOMA2), or 24 (SOMA3) g of marine
algae/kg of diet dry matter. On d 28 on diet, samples
of rumen fluid were collected for lipid analysis and
microbial DNA extraction. Appearance and identification
of biohydrogenation intermediates was determined
based on complementary gas chromatography and
Ag+-HPLC analysis of FA methyl esters. Total bacteria
and the Butyrivibrio group were studied in microbial
DNA by terminal RFLP analysis, and real-time PCR
was used to quantify the known Butyrivibrio bacteria
that produce trans-11 18:1 or 18:0. Dietary supplements
of sunflower oil alone or in combination with marine
algae altered the FA profile of rumen fluid, which was
associated with changes in populations of specific bacteria.
Inclusion of marine algae in diets containing sunflower
oil resulted in the accumulation of trans 18:1 and
10-O-18:0 and a marked decrease in 18:0 concentrations
in rumen fluid. At the highest levels of supplementation
(SOMA2 and SOMA3), marine algae also promoted a
shift in ruminal biohydrogenation pathways toward the
formation of trans-10 18:1 at the expense of trans-11
18:1. Changes in the concentration of biohydrogenation
intermediates were not accompanied by significant
variations in the abundance of known cultivated ruminal
bacteria capable of hydrogenating unsaturated FA. However, certain bacterial groups detected by
terminal RFLP (such as potentially uncultured Lachnospiraceae
strains or Quinella-related bacteria) exhibited
variations in their relative frequency consistent with
a potential role in one or more metabolic pathways of
biohydrogenation in the rumen.This work was supported by the Spanish Ministry
of Science and Innovation (MICINN; AGL2008-
04805-C02-02) and the Spanish National Research
Council (CSIC; 200940I034). P. G. Toral was granted a
fellowship from the CSIC (I3P Program). The authors
thank R. John Wallace and Nest McKain from the Rowett
Institute of Nutrition and Health (Aberdeen, UK),
and C. Jamie Newbold from the Institute of Biological, Environmental and Rural Sciences (Aberystwyth, UK)
for kindly providing the bacterial strains.Peer reviewe
