Organic acids 의 첨가가 in vitro 반추위 발효성상과 메탄 생성에 미치는 영향

Abstract

The objective of this study was to evaluate the in vitro effects of organic acids on methane emission and ruminal fermentation characteristics. We expected our methodology to result in a decrease of methanogens attached to the surface of rumen ciliate protozoa by addition of organic acids and in particular a decrease in methane emission. A fistulated Holstein cow of 650 kg body weight was used as a donor of rumen fluid. Organic acids (aspartic acid, fumaric acid, lactic acid, malic acid, and succinic acid) known to be propionate enhancers were added to an in vitro fermentation system and incubated with rumen fluid. The microbial population, including bacteria, protozoa, and fungi, were enumerated, and gas production, including methane and fermentation characteristics, were observed in vitro. Organic acids appeared to affect the rumen protozoan community. The rumen protozoal popuation decreased with the addition of aspartic acid, fumaric acid, lactic acid, and malic acid. In particular, the methane emission was reduced by addition of lactic acid. The concentration of propionate with all organic acids that were added appeared to be higher than that of the control at 12 h incubation. Addition of organic acids significantly affected rumen bacteria and microbial growth. The bacteria in added fumaric acid and malic acid was significantly higher (p<0.05) and protozoa was significantly lower (p<0.05) than that of the control. Microbial growth with the addition of organic acids was greater than the control after 48 h incubation.