Effect of Albizia myriophylla bark and its secondary metabolites on rumen fermentation parameters and microbial population

Abstract

The objective of this study was to evaluate the in vitro effects of Albizia myriophylla bark and its secondary metabolites on rumen fermentation parameters and microbial population, in particular its effectiveness for mitigating ruminal methanogenesis and its potential as a feed additive to enhance performance of ruminants. Control (50% concentrate + 50% Alfalfa), treatment 1 (10% Albizia replaced Alfalfa) and treatment 2 (20% Albizia replacement) were added to the rumen fluid-buffer mixture for 24h incubation. Total gas production, volatile fatty acids, pH, NH 3 -N, methane gas production and ruminal microorganisms were measured. Estimates of rumen microbial population using real-time PCR assay showed that supplementing different levels of Albizia did not affect the relative abundance of total bacteria, Fibrobacter succinogenes, Butyrivibrio fibrisolvens, Ruminococcus flavefaciens, Methanobacteriales, total protozoa and fungi but had a decreasing effect on Ruminococcus albus. There were no significant changes (p > 0.05) on any of the measured fermentation parameters (pH, NH3-N, VFA). Cumulative gas production and methane production at different inclusion levels of Albizia myriophylla were not affected by the experimental treatments. It was concluded that Albizia can probably be included in the diet of goats up to 20% without any adverse effects on ruminal fermentation, however its potential as alternative performance enhancer and methane mitigation agent was not confirmed.