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Live yeast as a possible modulator of polyunsaturated fatty acid biohydrogenation in the rumen

Julien, Christine and Marden, Jean-Philippe and Enjalbert, Francis and Bayourthe, Corine and Troegeler-Meynadier, Annabelle Live yeast as a possible modulator of polyunsaturated fatty acid biohydrogenation in the rumen. (2010) Revue de Medecine Veterinaire, 161 (8-9). 391-400. ISSN 0035-1555

(Document in English)

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Official URL: http://www.revmedvet.com/artdes-fr.php?id=1829


In dairy cows, several studies focused on the effects of sodium bicarbonate and fibre on ruminal linoleic acid (c9c12-C18:2) biohydrogenation (BH) whereas literature is scarce about the effect of live yeast, used as a feed additive. The objective of this in vivo study was to evaluate the capacity of two dietary feed additives, sodium bicarbonate and live yeast (Strain Sc47), and hay to modulate ruminal BH and particularly conjugated linoleic acids (CLA) and trans-monoenoic acids (t-C18:1) production. Four dry dairy cows fitted with ruminal cannula, were used in a 4×4 Latin square design. They were given a control diet (CD) at a daily feeding rate of 10.4 kg of dry matter/cow supplemented with 100 g/d of sodium bicarbonate or 5 g/d of live yeast or a hay diet formulated to provide the same main fatty acids (FA) as CD during a 14-d experimental period. Ruminal pH and redox potential were measured from 1 h before feeding to 8 h after, and ruminal fluid samples were taken at 5 h after feeding for volatile fatty acids, ammonia and fatty acid determination. In addition to the in vivo experiment, an in vitro experiment was carried out to ascertain the possible mode of action of live yeast on c9c12-C18:2 BH: ruminal fluid was obtained from a donor cow fed with hay and was incubated in batch cultures over 6 h with a 6-pH buffer using starch, urea and grape seed oil as substrates. Results gathered from both experiments suggested that live yeast supplement increased the accumulation of t-C18:1 compared to sodium bicarbonate and prevented the formation of C18:0 which is usually observed when hay is added to a high concentrate diet. The accumulation of t-C18:1 observed in presence of live yeast was probably due to an inhibition of the second reduction step as a result of a more complete isomerisation of c9c12-C18:2.

Item Type:Article
Additional Information:Thanks to Ecole Nationale Vétérinaire de Toulouse. The original PDF is available on Revue de Médecine Vétérinaire website : http://revmedvet.com
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Université de Toulouse > Ecole Nationale Vétérinaire de Toulouse - ENVT (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
French research institutions > Institut National de la Recherche Agronomique - INRA (FRANCE)
Other partners > LESAFFRE (FRANCE)
Laboratory name:
Deposited On:23 Nov 2010 16:29

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