Effect of yeast-fermented broken rice powder in para grass diet on methane production in an in vitro rumen incubation using cattle rumen fluid

Abstract

The study was conducted at An Giang University with the objective of determining the effects of varying levels of yeast-fermented rice bran supplementation (Saccharomyces cerevisiae)  on methane production in in vitro conditions, using Brachiaria grass (Brachiaria mutica) as the substrate. The experiment was designed in a completely randomized manner with four treatments, corresponding to fermented rice bran supplementation levels of 0%, 5%, 10%, and 15% w/w based on the dry matter of Brachiaria grass, each with three replicates.

The analysis results showed that the fermented rice bran contained a dry matter content of 42.86% and a crude protein content of 8.13% (based on dry matter). The pH values of the treatments differed significantly, with values of 6.99, 6.81, 6.68, and 6.64 corresponding to the fermented rice bran supplementation levels of 0%, 5%, 10%, and 15% based on dry matter (P<0.05). This supplementation in the Brachiaria-based diet under In vitro conditions did not affect the total gas production but significantly influenced methane concentration and total methane production, with values of 17.15%, 15.64%, 16.25%, and 14.83%, and 11.75, 10.45, 10.01, and 9.60 ml/500 mg dry matter, respectively, corresponding to the 0%, 5%, 10%, and 15% supplementation levels.

These findings suggest that the inclusion of fermented rice bran in a Brachiaria-based diet does not affect total gas production but significantly impacts methane concentration and total methane production.