Resumen
The wilting technique to increase the dry matter content has been used as an alternative to improve the quality of tropical grass silages. The wilting partially removes the water from the plant in order to improve anaerobic fermentation and limit the extent of undesirable secondary fermentations. In this sense, it was aimed in this experiment to evaluate the chemical composition of xaraés and piatã grass silage under different wilting times. The experimental design was completely randomized with four replications in a factorial 4 x 2 with four times of wilting (0, 2, 4 and 6 hours) and two cultivars of B. brizantha (xaraés and Piatã), totaling 32 experimental silos. For the process of ensilage the xaraés and piatã grass were harvested at growth stage of 40 days, and 20 cm from ground contents. The results showed that Brachiaria brizantha cultivars harvested at 40 days of growth can be ensiled using wilting technique, with a time of 4 hours of sun exposure for the piatã grass and 6 hours for the xaraés grass.