Effect of polyphenol-rich oil palm empty fruit bunch extract on in vitro rumen fermentation, fatty acid profile and microbial population

The aim ofthis study was toevaluate the effect ofoil palm empty fruit bunch (OPEFB) extract oninvitro rumen fermentation, fatty acid profile, and microbial population. Rumen fluid was obtained from three female dairy goats fed asimilar diet of60% Napier grass and 40% commercial pellets. The substrate used for the fermentation was aNapier grass and commercial pellet mixture (60 : 40 indry matter) and the treatment diets were: CON (substrate without OPEFB extract), OPEFB-5 (substrate with 5% ofOPEFB extract), OPEFB-10 (substrate with 10% ofOPEFB extract). The characteristics ofrumen fermentation including pH, fermentation kinetics, total gas production, volatile fatty acid (VFA) production, fatty acid (FA) production, and microbial populations were examined. Results showed that OPEFB supplementation decreased rumen acetate concentration, increased isoacid concentrations aswell aspalmitic acid concentration. Meanwhile, the population oftotal bacteria, protozoa, and B.fibrisolvens decreased with the OPEFB supplementation. OPEFB-5 resulted inamoderate amount ofacetate, isobutyrate, isovalerate concentration, insoluble fraction ofgas production (but degradable), estimated potential gas production aswell asB.fibrisolvens population when compared with the control and OPEFB-10 diet. Therefore itissuggested that the supplementation ofOPEFB extract at5% issuitable and practical tobeused inruminant feed without causing animperative effect onrumen fermentation.