Effect of Presence of Large Entodiniomorphid Protozoa on the Rumen Bacterial Flora, Fauna Composition of Small Entodinia and in vitro Cellulolysis and Xylanolysis

Abstract

In vitro cultures of rumen fluid taken from defaunated (period-DF), Entodinium spp.-inoculated (period-E), and Entodinium spp., Diploplastron affine and Polyplastron multivesiculatum-inoculated (period-EDP) sheep rumen were used to determine the effect of presence or absence of protozoa on the digestibility of cellulose and xylan.Digestibilities of cellulose during48h incubation in period-DF, -E, and-EDP were respectively0.524, 0.709and0.739. Those of xylan were respectively0.431, 0.466and0.598.Stimulation of cellulolytic bacteria by the presence of protozoa was shown to be responsible for higher cellulolysis and engulfement and digestion of fine xylan particles by two large entodiniomorphid protozoa would improve xylanolysis.Propionate and butyrate production from cellulose were significantly increased by the inoculation of Entodinium spp.(period-E) and further increase was observed in the period-EDP. While acetate production did not show any notable change.Cellulose carbon recoveries into the fermentation end products was lowest in the period-DF, suggesting higher synthetic efficiency in the defaunated sheep rumen. Bacterial number reduced from18.8to5-7 (×10⁹/ml) by the inoculation of protozoa. Gram negative strains decreased while gram positive strains maintained their numbers.Frequency of Entodinium spp. was modified after inoculation of D.qffine and P. multivesiculatum;larger species decreased and smaller species increased.