Use of the rumen simulation technique (rusitec) to provide micro-organisms for assessing forage rate-of-fermentationin vitro:effect of solid food input to rusitec

Abstract

In a previous experiment (Barbi, Owen & Theodorou, 1993) effluent fluid from thein vitrorumen simulation technique (RUSITEC - Czerkawski & Breckenridge, 1977) was used as a source of inoculum when fermenting forage in the Pressure Transducer Technique (PTT - Theodorou, Williams, Brooks, Dhanoa, McAllan & Gill, 1993). The main objective was to replace rumen fistulated animals for assessing the fermentation kinetics of forages. However, low microbial activity in RUSITEC effluent-fluid affected the results, such that fermentation profiles were lower than those in controls inoculated with rumen liquor (Barbiet al,1993).In the present study, in an attempt to increase the microbial cellulolytic activity in the effluent fluid, we altered the particle size and increased the amount of substrate added daily to the RUSITEC vessels. Two particle sizes were examined in an attempt to enhance microbial activity and growth by increasing the availability of colonization surfaces.