Effect of Waste Products on Ruminal Microbe Population and Rumen Charateristics in Vitro

Abstract

Certain tropical plants may have a nutritional value beyond simply their nutrient content, i.e. as rumen-manipulating agents that can be used as an alternative mean to solve problems in animal nutrition and livestock production in Indonesia. The objective of the present study was to measure the nutrient and phytochemical contents, and their effects on rumen microbial population and rumen fluid characteristics in vitro, of different parts of Uncaria gambir leaves and Cacao (Theobroma cacao L). Determination of nutrient content according to AOAC procedures (1995), fiber fractions (NDF and ADF) according to van Soest et al. (1991), phytochemical (alkaloid, phenol, terpenoid, saponin and tannin) content qualitatively and the effect of plant fractions on rumen microbial fermentation were evaluated in in vitro batch culture of rumen fluid. Parameters observed were total rumen ciliate population, total bacteria, cellulolyt ic bacteria, total VFA, ammonia N concentration, and pH. There was no significant effect (P>0.1) of phenolic and tannin present in Uncaria gambir on total microbial population, although the presence of saponin indicated a tendency to reduce the number of protozoa. However, it gave a significant effect (P<0.01) on VFA total and ammonia N concentration compared to control. Meanwhile, fractions of cacao waste (cacao pod and leaves) resulted in significant effect (P<0.01) on pH, ammonia N concentration and VFA total. But, the presence of phenolic (tannin) and alkaloid (theobromine) has no significant effect on total ciliate, total bacteria and cellulolytic bacteria and therefore they may have the potential as beneficial manipulators of rumen fermentation.