The objective of this work was to evaluate the biometric measurements and nutrient contents of the corn, sorghum, and pearl millet crops from 30 days after sowing up to ensiling time. The experiment was conducted in a randomized complete block design, in which the three crops were evaluated with eight replicates. Stem height and diameter and leaf length and width were measured to determine plant growth. In addition, samples were collected to evaluate plant chemical composition. For the characterization of nutrient accumulation and biometric evaluation, linear and nonlinear models were used. Dry matter accumulation did not differ between corn and sorghum, but decreased in pearl millet from the fiftieth day up to ensiling. Crude protein, ashes, and neutral detergent fiber tend to reduce over time. The biometric variables do not differ between corn, pearl millet, and sorghum from 30 days after sowing until ensiling time.