Comparison of ruminal fermentation characteristics and microbial population in swamp buffalo and cattle

The aim of this study was to determine the ruminal cellulolytic bacterial population in swamp buffalo and beef cattle fed on rice straw by real-time PCR techniques. Four, rumen-fistulated swamp buffalo and four beef cattle (Native × Brahman) were randomly assigned to receive rice straw as a main feed with minimal amount of concentrate. All animals were allowed to adapt to feeds respective before samplings were conducted. It was found that diurnal ruminal pH and NH3-N concentration of buffalo were not different with those found in cattle, population of bacteria and fungal zoospores while the protozoal population were lower (P < 0.05). In addition, the nutrient digestibilities of DM, OM, CP, NDF and ADF were found higher in buffalo than in cattle. Employing the real-time PCR techniques for the quantification of cellulolytic bacterial numbers (Ruminococcus albus) in the digesta of swamp buffalo, the results revealed significant higher in buffalo than those in cattle. However, at 4 h post-feeding R. albus were significantly higher in buffalo than those in cattle measured in rumen fluid, while F. succinogenes resulted in higher number in cattle than those in buffalo. Interestingly, the values found in the digesta samples were higher in cellulolytic bacteria than those found in the rumen fluid. This finding indicates higher ability of swamp buffalo in digesting low-quality roughages, especially rice straw.