EFFECTS OF PASTURE DEFERMENT ON FORAGE YIELD AND CHEMICAL COMPOSITION OF Panicum maximum CV. TOBIATÃ

Abstract

An experiment was conducted in Porto Velho, Rondônia, for pasture deferment and utilization of the forage accumulated of with the purpose to determine the best time Panicum maximum cv. Tobiatã for herd supplementation during the dry season. The experimental design was a randomized complete-block (split-plot) with three replications. The periods of deferment began on February 28, March 28 and April 28 and constituted the main plots, and the months of utilization (June 30, July 30, August 30 and September 30) the sub-plots. Results indicate the feasibility of stockpiling the grass during the rainy season, to provide forage for herd supplementation in the dry season. For utilization in June or July, the herbage deferred in February provided higher dry green matter (DGM) yield, while for utilization in August or September, the herbage stockpiled in March was the most productive. The grass, irrespective of deferment dates, showed significant reductions (1 3 <0.05) in crude protein (CP) content and in vitro DOM digestibility (I VDGMD) towards the later utilization date. However, the highest CP yields were obtained in herbage stockpiled in March and used in July or August. Deferment starting in March or April and to be used in June produced forage with higher IVDGMD coeficient. In order to obtain higher forage yields with better quality, it is suggested to start deferment in February for pasture utilization in June or July, and in March for pasture utilization in August or September.