Suplementação de novilhos nelore no período de transição águas-seca em pastagens de capim-piatã diferidas

Abstract

The effects of different levels of supplementation on performance and forage dry matter intake of steers grazing Brachiaria grass (Brachiaria brizantha cv. Piatã), deferring by 60 and 100 days, during the rainy/dry transition period, on Cerrado Biome, were evaluated. The treatments were: control (mineral salt plus urea offered ad libitum); proteic supplement offered at 0.2% BW and proteic-energetic supplement, offered at two levels (0.3 and 0.5% BW). Performance trial was evaluated for a period of 84 days. Dry matter intake was estimated using LIPE® as external marker, and diet digestibility obtained by hand pluckingsampling. Forage deferring for 60 and 100 days allows adequate quantities of green forage mass and high rates of forage accumulation, being effective strategy to store forage to be used during the rainy/dry transition period. Comparing to control, supplementation increasedtotal dry matter intake in 8.3; 6.6 and 14.6%, for 0.2, 0.3 and 0.5% BW, respectively. The average intake of supplements was 0.167; 0.597; 0.865 and 1.469 kg/animal/day, and the average daily gain (ADG) 0.686; 0.761; 0.719 and 0.850 kg/animal/day, for control, 0.2, 0.3 and 0.5% BW, respectively. Results suggest that all strategies of supplementation reachsimilar performance during the rainy/dry transition period, under conditions of high herbage availability. All supplementation strategies are economicaly viable. It is recomended to antecipate proteic suplementation from dry season to rainy/dry transition period, for betteranimal performance and economic results