The effect of eucalyptus essential oil on sheep in vitro fermentation parameters and production of methane

The aim of this study was to investigate the effect of different levels of eucalyptus essential oils on in vitro rumen fermentation parameters and methane production. Test gas production has done with using rumen fluid of fistuled sheep and with five replicates for each treatment in a completely randomized design.The parameters of studied was include 96-hour fermentation kinetics, fermentation parameters and protozoa population. The results showed eucalyptus essential oil were increased a (gas production from the immediately soluble fraction), b (gas production from the insoluble fraction) and potential extent of gas production (a+b). The methane produced was reduced (p=0.000) from 8 to 40 percent. Simultaneously with the increase in essential oil, nitrogen ammonia and total concentrations of fatty acids decreased (p<0/001), and partition factor and microbial biomass were increased. Level 5 ml of essential oils cased to improvement parameters of 24-hour gas, organic matter degradation and energy metabolism compared with other treatments. There is the correlation of 48-73 percent between reduction methane gas and protozoa population. The secondary metabolites essential oil reduced the total protozoa population and geneses of Entodinium, Ophryscolex, Isotricha, Dasitricha and Diplodinium. In general, the results of this experiment showed that eucalyptus oil has antimicrobial activity and were reduced methane emissions and improved the production of microbial protein.