AN EVALUATION OF INVITRO METHOD USING BUFFALO FAECES AS A SOURCE OF INOCULUM FOR THE MEASUREMENT OF TROPICAL FEED DIGESTIBILITY

Abstract

The use of faeces as a source of inoculum has been reported to be a reliable method for measuring in vitro feed digestibility. However, the method was based on studies carried out in temperate or subtropik regions so its application to measure digestibility oftropical feeds may not be accurate. In the first experiment, a relationship between faeces density (g faeces/L distilled water) and in vilro digestibility was studied to establish an optimum level of faeces to be used in the inoculum. In the second experiment, in vii‘/"0 digestibility of elephant grass, rice straw and pangola grass was measured using faeces liquor as inoculum. In this study, the faecal inoculum was dissolved in distilled water, not in artificial saliva as commonly used in previous studies, due to technical and economical considerations for application in Indonesia. The in virro digestibility data obtained by using faecal inoculum were plotted agains those obtained by using rumen fluid as the inoculum to establish regression equations for the tested feeds. The results show that level of faeees in the inoculum did not significantly affect in vilro digestibility of dry matter. Relatively good regressions coefficient between in vi/1'0 digestibility using faecal inoculum and rumen fluid inoculum were obtained using fecal density of 350 and 400 g/L distilled water. However, the regression equations vary considerably between feed samples, indicating that the use of buffalo faeces as a source of inoculum requires further validation before the method can be used satisfactorily for Indonesian forages.