Effect of cashew nut shell liquid on metabolic hydrogen flow on bovine rumen fermentation

Effect of cashew nut shell liquid (CNSL), a methane inhibitor, on bovine rumen fermentation was investigated through analysis of the metabolic hydrogen flow estimated from concentrations of short-chain fatty acids (SCFA) and methane. Three cows were fed a concentrate and hay diet without or with a CNSL-containing pellet. Two trials were conducted using CNSL pellets blended with only silica (trial 1) or with several other ingredients (trial 2). Methane production was measured in a respiration chamber system, and energy balance and nutrient digestibility were monitored. The estimated flow of metabolic hydrogen demonstrated that a part of metabolic hydrogen was used for hydrogen gas production, and a large amount of it flowed into production of methane and SCFA in both trial 1 and 2, when CNSL was administered to the bovine rumen. The results obtained by regression analyses showed that the effect of CNSL supply on methane reduction was coupled with a significant (P < 0.01) decrease of acetate and a significant (P < 0.01) increase of propionate and hydrogen gas. These findings reveal that CNSL is able to reduce methane and acetate production, and to increase hydrogen gas and propionate production in vivo.

Mitsumori, M., O. Enishi, T. Shinkai, K. Higuchi, Y. Kobayashi, A. Takenaka, K. Nagashima, M. Mochizuki, & Y. Kobayashi (2014) Effect of cashew nut shell liquid on metabolic hydrogen flow on bovine rumen fermentation, Animal Science Journal 85(3):227-232.