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BioMed Research International
Volume 2013 (2013), Article ID 349129, 8 pages
http://dx.doi.org/10.1155/2013/349129
Research Article

Effects of Flavonoids on Rumen Fermentation Activity, Methane Production, and Microbial Population

1Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
2Agriculture Biotechnology Research Institute of Iran (ABRII), East and North-East Branch, P.O. Box 91735/844, Mashhad, Iran
3Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
4Ferdowsi University of Mashhad, International Branch, P.O. Box 91779/4888, Mashhad, Iran

Received 14 April 2013; Revised 12 August 2013; Accepted 26 August 2013

Academic Editor: Nico Boon

Copyright © 2013 Ehsan Oskoueian et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This research was carried out to evaluate the effects of flavone, myricetin, naringin, catechin, rutin, quercetin, and kaempferol at the concentration of 4.5% of the substrate (dry matter basis) on the rumen microbial activity in vitro. Mixture of guinea grass and concentrate (60 : 40) was used as the substrate. The results showed that all the flavonoids except naringin and quercetin significantly ( ) decreased the dry matter degradability. The gas production significantly ( ) decreased by flavone, myricetin, and kaempferol, whereas naringin, rutin, and quercetin significantly ( ) increased the gas production. The flavonoids suppressed methane production significantly ( ). The total VFA concentration significantly ( ) decreased in the presence of flavone, myricetin, and kaempferol. All flavonoids except naringin and quercetin significantly ( ) reduced the carboxymethyl cellulase, filter paperase, xylanase, and β-glucosidase activities, purine content, and the efficiency of microbial protein synthesis. Flavone, myricetin, catechin, rutin, and kaempferol significantly ( ) reduced the population of rumen microbes. Total populations of protozoa and methanogens were significantly ( ) suppressed by naringin and quercetin. The results of this research demonstrated that naringin and quercetin at the concentration of 4.5% of the substrate (dry matter basis) were potential metabolites to suppress methane production without any negative effects on rumen microbial fermentation.