Evaluation of three cultivars of Panicum maximum Jacq. under grazing.: Chemical composition and in vitro organic matter digestibility

A study was conducted to evaluate three cultivars of Panicum maximum Jacq. under rotational grazing for the nutritive value, where the estimates of crude protein, neutral detergent fiber, acid detergent fiber, lignin, cellulose, silica, and in vitro digestibility of the organic material were performed in samples of leaves and stems. Additional nitrogen was applied in cv. Tanzania at the end of the rainny season. Samples were taken in June, September, and October 1998 and in March 1999. Some differences among treatments were observed. In general, cv. Massai showed a lower nutritive value with lower crude protein and digestibility, and higher neutral detergent fiber, acid detergent fiber, and lignin, either in samples of leaves or in stems. Therefore, its utilization as a forage option should be based on other agronomic characteristics. The cv. Mombaca exhibited higher concentrations of silica and its nutritive value was not affected by nitrogen fertilization at the end of the rainny season, except for an increase in the percentage of crude protein and a reduction in the amount of lignin and silica in March. The nutritive value of the stems was inferior to the leaves. The nutritive value was highest in all treatments at the beginning of the rainny period.