Effect of the source and concentration of saponins on in vitro and ruminal methane production

Abstract

The aim of the work was to assess the effect of incorporation of different sources of saponins on the in vitro total gas (TG) and ruminal methane (CH4) productions, kinetics of fermentation, digestibility of dry matter (IVDDM) and organic matter (IVDOM). Treatments were interaction of three concentrations (3.5, 7.0 and 14.0 mg/g dry matter) of saponins from Yucca schidigera (YS), Gliricidia sepium (GS), Enterolobium cyclocarpum (EC) and a control (Pennisetum purpureum [PP] alone). A sample of 1.0 g of each treatment was incubated in vitro in a complete randomized design with factorial arrangement with three replicates per treatment. TG from PP was unaffected (P>0.05) by the inclusion of saponins from YS, GS and EC. Methane production was not affected (P>0.05) by any saponins from YS at any level of inclusion. When saponins from GS and EC were incorporated at concentrations of 7.0 and 14.0 mg/g DM, methane production was increased (P<0.05). IVDDM and IVDOM were significantly increased (P<0.05) with all sources of saponins, except with those from YS at concentration of 14.0 mg/g DM when IVDOM was reduced (P<0.05). It is concluded that saponins from different tropical plants did not reduce methane production under in vitro conditions.