Study of rumen metagenome community using qPCR under different diets

• Major fibrolytic and non-fibrolytic bacterial communities were detected.
• R. flavefaciens were the highest in population in the rumen of Surti buffalo fed wheat straw as roughage source.
• In non-fibrolytic bacteria, the maximum population was observed in Selenomonas ruminantium.

The aim of this study was to detect the major bacteria present in rumen microbiota. Here, we performed qPCR based absolute quantitation of selected rumen microbes in rumen fluid of river buffalo adapted to varying proportion of concentrate to roughage diets. Animals were adapted to roughage-to-concentrate ratio in the proportion of 100:00 (T1), 75:25 (T2), 50:50 (T3) and 25:75 (T4) respectively for 30 days. At the end of each treatment, rumen fluid was collected at 0 h and 2 h after feeding. It was found that among fibrolytic bacteria Ruminococcus flavefaciens (2.22 × 108 copies/ml) were highest in T2 group and followed by 1.11 × 108 copies/ml for Fibrobacter succinogenes (T2), 2.56 × 107 copies/ml for Prevotella ruminicola (T1) and 1.25 × 107 copies/ml for Ruminococcus albus (T4). In non-fibrolytic bacteria, the Selenomonas ruminantium (2.62 × 107 copies/ml) was predominant in group T3 and followed by Treponema bryantii (2.52 × 107copies/ml) in group T1, Ruminobacter amylophilus (1.31 × 107copies/ml) in group T1 and Anaerovibrio lipolytica (2.58 × 106 copies/ml) in group T4. It is most notable that R. flavefaciens were the highest in population in the rumen of Surti buffalo fed wheat straw as roughage source.