Effect of cashew nut shell liquid at varying inclusion levels on rumenfermentation and methane production in vitro

ABSTRACT

Essential oils are possible natural antibioticalternatives for manipulating ruminal fermentation in order to improve the utilization of nutrient in ruminants. This studyevaluated the effect of cashew nut shell liquid (CNSL) at varying inclusion levels on in vitro gas production, nutrient degradation, and post-incubation parameters. Experimentaldiets consisted of Panicum maximum (Ntchisi) grass as basal diet and supplemental pellets treated with 0, 5, 10 and 15 ml/kg of cashew nut shell liquid. Proximate composition ofexperimental diets was analysed. In vitro experiment was carried out on experimental diets (P. maximum and concentrate pellets at ratio 7030) for 24 hours using goat rumen liquor as inoculum. Results showed that CNSLinclusion had a significant effect (P < 0.05) on the ether extract and metabolizable energy of experimental pellets. Dietary treatment with 15 ml/kg of CNSL had the lowest (P < 0.05) invitro gas production. Inclusion of CNSL significantly inhibited methane production at 5 ml/kg (18%), 10 ml/kg (34%) and 15 ml/kg (57%) CNSL inclusion levels (P < 0.05).Ammonia-N and TVFA decreased significantly with CNSL inclusion. Significant reduction (P < 0.05) in short-chain fatty acid, metabolizable energy, and organic matter degradabilitywere recorded with increasing CNSL inclusion levels.