Forage legumes have played important roles in crop-livestock systems and in forage research. Research conducted to test the effect of forage legumes on livestock productivity in the sub humid zone of Nigeria is scanty. This research aimed at developing a model that can correctly predict the growth rate and biomass accumulation of Mucuna pruriens, Centrosema pubescens, Gliricidia sepium, and Leucaena leucocephala. The experiment was conducted at the screen-house of the Faculty of Agriculture, Federal University, Oye-Ekiti, Ikole campus (07°48.308 N, 005°29.573 E; 548.4m above ground level). Planting was done using a completely randomized design (CRD) in 4 rows with 4 replicates of 8 pots of each legume species and a spacing of 1 m apart was applied between each bed. The soil used for this study contained 39.83% organic matter before planting and 57.72% after harvesting. The highest growing legume was Mucuna pruriens during the experiment. Plant heights of the 4 legume species were different from each other. Leucaena leucocephala had the highest N and CP contents and this was observed in all the cuttings, at wk 2 (2.83, 2.28, 1.95, 1.77), 4 (3.05, 2.30, 1.69, 1.46), 6 (3.04, 2.70, 2.22, 1.77), and 8 (2.51, 2.21, 1.89, 1.53). Moisture content (MC) varied between the legume species and the times of cuttings; Leucaena leucocephala had the highest MC throughout the 8 wk of study. Crude protein, crude ash (CA), and crude fat (CF) varied among the 4 species with values ranging from 15.71 to 9.59% CP, 16.16 to 9.86% CA, and 2.41 to 1.47% CF at wk 8 of the experiment with Leucaena leucocephala having the highest values and Mucuna pruriens the least. There were fluctuations in the nutrient contents of the legume species due to cutting times. Growth rate of legumes was observed throughout the course of undertaking this study and varietal differences were observed with Mucuna pruriens the fastest. The observed biomass accumulation was 39.26 to 80.51% whereas the growth rate of the legume was 87.39 to 88.98%.