Modulatory effects of condensed tannin fractions of different molecular weights from a Leucaena leucocephala hybrid on the bovine rumen bacterial community in vitro

BACKGROUND: Condensed tannin (CT) fractions of different molecular weights (MWs) may affect rumen microbial metabolism by altering bacterial diversity. In this study the effects of unfractionated CTs (F0) and five CT fractions (F1-F5) of different MWs (F1, 1265.8Da; F2, 1028.6Da; F3, 652.2Da; F4, 562.2Da; F5, 469.6Da) from Leucaena leucocephala hybrid-Rendang (LLR) on the structure and diversity of the rumen bacterial community were investigated in vitro. RESULTS: Real-time polymerase chain reaction assay showed that the total bacterial population was not significantly (P > 0.05) different among the dietary treatments. Inclusion of higher-MW CT fractions F1 and F2 significantly (P