Effects of Organic Acids on In Vitro Ruminal Fermentation Characteristics and Methane Emission

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. [2,4,13,18]. 그리고 propionic acid전구물질은 H2를 제거하고 [19], 섬유소 분해 bacteria와 cellulose분해율을 증가한다고 알 려져 있다 [2,18]. 따라서, 본 연구의 목적은 여러 가지 organic acids를 첨가하여 in vitro 반추위 발효 성상, 건물소화율, 반추 위 혐기성 미생물 수(bacteria, fungi 및 protozoa) 및 메탄생성 에 미치는 영향과 기작을 규명하고자 한다.

The effects of fumaric and malic acids on the in vitro true digestibility of some alternative feedstuffs for ruminants

“…In the present study, only 0.1% and 0.3% dose of FA increased protozoa counts numerically and MA showed a reducing effect on protozoa counts with increasing dose. This finding is consistent with the reports of other studies (17,27,32) investigating the effects of organic acids on rumen microorganisms. Ok et al (27) reported that FA and MA have different effects on bacteria, protozoa and other microbial community.…”

“…This finding is consistent with the reports of other studies (17,27,32) investigating the effects of organic acids on rumen microorganisms. Ok et al (27) reported that FA and MA have different effects on bacteria, protozoa and other microbial community. They reported that these acids had an increasing effect on rumen bacteria, but decreased the number of methanogenic archaea species that could form complexes with protozoa.…”