عنوان مقاله [English]
The effect of three levels of eucalyptus leaf (0, 28.65 or 57.37mg/200mg substrate), which were either oven, freeze or air dried on in vitro ruminal fermentation characteristics was assessed. The studied parameters were in vitro gas production (IVGP), methane production, ammonia (NH3-N) concentration, in vitro organic matter degradability, partitioning factor (PF) (ratio of substrate truly degraded to gas volume produced at 24 h of incubation) and total volatile fatty acids (VFAs) concentration. Three subfamily of Entodiniinae, Ophryscolecinae, Diplodiniinae and family of Isotrichdaewere, also, identified and enumerated. Methods of air (L effect; P<0.01) and freeze drying (Q effect; P<0.05) have decreased the concentration of VFAs. However, oven drying method has increased propionic acid concentration (L effect; P<0.01). Adding eucalyptus leaf has significantly decreased gas production from insoluble fraction (b) (L effect; P<0.01), IVGP at 24, 54 h (L and Q effect; P<0.01), methane production (L effect; P<0.05), NH3-N concentration (L effect; P<0.01) and total VFAs (L effect; P<0.01). However, such additive has improved PF (L effect; P<0.01) only at 57.31 level. Moreover, the inclusion of eucalyptus has significantly decreased total protozoa population (P<0.01), Entoodiniinae subfamily (P<0.01) and Isotrichdae family (P<0.05). The results suggest that eucalyptus leaves has positively manipulated in vitro ruminal fermentation, and oven dried method was more effective than two other methods.