This study aims to evaluate the level of Indigofera zollingeriana with Pennisetum purpureum cv. Mott  in ration on rumen fermentation characteristics (total VFA, NH3 and protozoa population) in vitro. The study used a completely randomized design (CRD), consisting of 5 treatments and 4 replications. P1 = 60% Pennisetum purpureum cv. Mott, P2 = 45% Pennisetum purpureum cv. Mott + 15% Indigofera zollingeriana, P3 = 30% Pennisetum purpureum cv. Mott + 30% Indigofera zollingeriana, P4 = 15% Pennisetum purpureum cv. Mott + 45% Indigofera zollingeriana, P5 = 60% Indigofera zollingeriana. All treatments received an additional 40% fine ricebran. The results showed that the level of Indigofera zollingeriana flour with Pennisetum purpureum cv. Mott had no significant effect on total VFA and NH3.  Total VFA and NH3 ranged from 131.65 mM-143.24 mM and 12.61 mM-13.74 mM, respectively. Meanwhile, the population of protozoa had a significant effect (P<0.05). DMRT further test results showed that P3 was significantly  (P<0.05) lower than P1, P2, P4 and P5. The average population of the protozoa ranged from 53.125 cells/ml to 90,625 cells/ml. Based on the results of the study, it can be concluded that the administration of Indigofera zollingeriana leaves by 30% was able to reduce the protozoan population in the rumen of FH cattle but had no significant effect on total VFA production and ammonia (NH3) concentration. Keywords: Rumen Fermentation Characteristics, Indigofera zollingeriana, In Vitro

The objective of this research was to evaluate the effects of different levels of Indigofera zollingeriana and Pennisetum purpureum cv. Mott on the in vitro digestibility and rumen pH. The treatments were T1=60%Pennisetum purpureum cv. Mott, T2 = 45% Pennisetum purpureum cv. Mott + 15% Indigofera zollingeriana, T3 = 30% Pennisetum purpureum cv. Mott + 30% Indigofera zollingeriana, T4 = 15% Pennisetum purpureum cv. Mott + 45% Indigofera zollingeriana, and T5 = 60% Indigofera zollingeriana. All the treatments supplied with rice bran 40%. The result showed that there are no significant difference on ruminal pH (P>0.05). The ruminal pH were in normal range that were 6.66-6.73. The increasing level of Indigofera zollingeriana to Pennisetum purpureum cv. Mott had no significant effect to dry matter and organic matter digestibility. The dry matter digestibility were around 60,56%-70.46% while the organic matter digestibility were around 60.01%-65.99%. This research indicated that the increasing level of Indigofera could decrease the digestibility. The treatment T4 (15% P. purpureum + 45% Indigofera zollingeriana) showed the highest digestibility values.