摘要:The objective of the present study was to investigate feed digestibility and methane emissions of ration based on oil palm by-products on addition of probiotics, namely Acetoanaerobium noterae and Saccharomyces cerevisiae and banana stem in vitro . The substrate, i.e., oil palm by-products consisted of oil palm midrib, oil palm leaf, oil palm kernel cake and oil palm sludge in the ratio of 30, 30, 30 and 10%, respectively. The following treatments were tested: control (R0), R0+ S. cerevisiae (R1), R0+ A. noterae (R2), R0+ S. cerevisiae + A. noterae (R3), R0+ banana stem (R4), R0+banana stem+ S. cerevisiae (R5), R0+banana stem+ A. noterae (R6) and R0+banana stem+ S. cerevisiae + A. noterae (R7) . The treatments were incubated in vitro with buffered-rumen fluid in four replicates (represented by three incubation units per replicate), conducted for 48 h at 39oC. Gas production and methane emission were measured at regular time point intervals. After the incubation, digestibility, Volatile Fatty Acids (VFA), ammonia and microbial counts were determined. Results showed that the highest dry matter digestibility was shown by R5 and the best reduction of methane emission was shown by R2 at 12 h of incubation. In conclusion, supplementation of probiotics did not affect the digestibility of ration based on oil palm by-products but A. noterae addition was potential to mitigate ruminal methane emission.