Fertilization becomes an important factor in plant production management. The availability of pastures in cattle’s industry, therefore, becomes a prerequisite step. Current research was then aimed to know the effect of combined-fertilizers between cattle’s manure and urea to the growth of three species of grasses which commonly cultivated for grassing, including their best combination as part of a good management practices on crop production. In order to answer the question, a split plot design was applied to observe the effect of combined-fertilizers between cattle’s manure and urea toward plant’s height and mass production along the three grassing periods. The main plot was three species of grasses as follows: Setaria anceps, Nevalensis, and Brachiaria Hybrid cv “Mulato”, while the sub-plot is combined-fertilizers of cattles’ manure at concentrations of 10 and 20 tons per hectare per grassing period and urea at concentrations of 100, 150 and 200kg per hectare per grassing period. Each treatment was performed in triplicates, to end up a total of 54 treatment plots. The observed variables were plant’s height, fresh and dry masses, these data were obtained from three grassing periods and analysed statistically. The currfent study indicated the genetic factors of the grasses were taking more significant role than treated-combined fertilizers. Here, different types of grasses showed significant different among them, in all observed parameters, while the combined-fertilizers showed a linear graph in all variables. The best dosage of combined-fertilizers, however, was reached by combination of 20 tons cattles’ manure and 200 kgs urea per hectare per grassing period.