Methane Production and Methanogens Diversity in in vitro Ruminal Fermentation with Mahogany Leaves Meal (Swietenia mahagoni) as Tannin Source

Swietenia mahagoni has been extensively studied and applied as feed additives, a strategy to manipulate rumen fermentation in reducing methanogenesis. The research aimed to determine the effect of using Swietenia mahagoni as tannin source on methane production, gas production kinetics and the diversity of methanogenic archaea by in vitro rumen fermentation. Swietenia mahagoni was given to substitute the elephant grass at levels of 0, 25, and 50. Fermentation was carried out by in vitro gas production technique according to Menke and Steingass. Methane was analyzed using gas chromatography (GC) methode. Terminal restriction fragment length polymorphism (TRFLP) analysis was used to detect changes of rumen methanogenic archaea diversity. Result showed that Swietenia mahagoni leaves with level 50 reduced methane production by 39,26 (P=0,08). Gas production from insoluble fraction (b) decreased as much as 47.23 from control with using Swietenia mahagoni leaves 50. The uncultured methanoculles was dominating community member 36.35 with MspI, while uncultured euryarchaeote clone is 80.24 MCR-F1SP-1 with TaqI. Inclusion of Swietenia mahagoni as much as 50 in diet could decrease methane production, gas production from potential degraded fractions and diversity of methanogenic archaea.