Yield and nutritional value of BRS Capiaçu grass at different regrowth ages

Abstract

The objective was to evaluate the productivity, chemical composition, ruminal degradability of dry matter and digestibility of BRS capiaçu grass (Pennisetum purpureum Schum.) managed at five regrowth ages. A completely randomized design with ten replications was used in the BRS capiaçu elephant grass subjected to five cutting intervals (30, 60, 90, 120 and 150 days) in the summer, making a total of 50 plots with a useful area of 4 x 2 m. There were daily increases in the dry matter production in the order of 382 kg ha-1, with 49,859 kg ha-1 being produced at 150 regrowth days. The dry matter content and organic matter linearly increased (P < 0.01) at different regrowth ages. The crude protein content, in vitro dry matter digestibility and in vitro digestibility of neutral detergent fiber linearly reduced (P < 0.01) 0.037%, 0.196% and 0.256% per day, respectively. Potential degradability of dry matter decreased from 68.9% at 30 days to 44.7% at 150 regrowth days (0.194 percentage units per day). The rate of degradation of fraction B 'c' was not modified (P = 0.94), averaging 1.46% hour-1. In the cultivation of BRS capiaçu elephant grass in the summer season, in the northern region of Minas Gerais, the age for harvesting between 90 and 120 days of regrowth is recommended.