This research aims to determine the effect of using alternative energy sources in the form of banana tubers and rejected cassava in complete pellet feed with different levels on VFA, NH3 and pH levels in vitro. The method used in this research is an experimental method using a completely randomized design (CRD) with 4 treatments and 4 replications, the treatments in this research are: R0; complete feed pellets 40% banana weevil + 60% concentrate, R1; complete feed pellets 60% banana weevil + 40% concentrate, , R2; pelleted complete feed (40% cassava + 60% concentrate, R3; pelleted complete feed 60% cassava + 40% concentrate. The data obtained were analyzed using analysis of variance. Based on the results of statistical analysis, it showed that the treatment had a significant effect (p<0, 05) on VFA, NH3 and rumen fluid pH levels. The conclusion of this research is that based on the discussion above, it is concluded that the use of different energy source materials in complete pelleted feed is able to increase VFA production and NH3 concentration and rumen fluid pH in vitro to the best level. 40%.