A study of the in vitro fermentation dynamics of the forages star grass (Cynodon plectostachyus; E), Guinea grass (Megathyrsus maximus; G) and Leucaena leucocephala (L), available in intensive silvopastoral systems (ISS) was carried out. Samples of these forages were harvested in ISS set in tropical dry forest in the Valle del Cauca, Colombia. With these forages, ten mixes or different treatments were generated: E100, G100, L100, E33G66, E66G33, L33E66, L66E33, L33G66, L66G33 and L33E33G33. The shorter lag phase was observed with L100 (7.02 h) and E33G66 (7.11 h), lower (α= 0.05) than that of L33E66 (10.22 h) and G100 (9.85 h). The maximum production of gas (a) ranged between 97.34 and 253 ml/ g substrate for L100 and G100, respectively. The lowest HIP value was obtained with L100 (23.3 hours) and the gas accumulated to that point was 35.08 ml, which coincides with the lower value. The treatments that most accumulated gas were the grasses alone or their mixtures and those with the least accumulated gas included leucaena. Regarding FP, after 24 hours of incubation, the greater values occurred with L100 and mixtures that included leucaena. It is concluded that the inclusion of Leucaena was associated with decreases in the lag phase time and maximum gas production rates and with high values of FP, characteristics that may be associated with more efficient fermentation processes.