Valor nutritivo de gramíneas forrageiras tropicais irrigadas em diferentes épocas do ano

Abstract

Bromatological composition and in vitro dry matter digestibility (IVDMD) of six forage grasses, under different irrigation depths and seasons, were evaluated. The experiment was carried out in a completely randomized arrangement, with two replications, in a split-split plot design. six grass species (Xaraés, Mombaça, Tanzânia, Pioneiro, Marandu, and Estrela) constituted the plots, six irrigation depths (0%, 18%, 45%, 77%, 100%, and 120% of the reference) the split-plots, and two seasons (autumn/winter and spring/summer) the split-split-plots. In order to vary irrigation depths, a line source sprinkler system was used. Raw protein (RP), neutral detergent fiber (NDF), and IVDMD were evaluated. Higher RP and IVDMD levels were found in autumn/winter and higher NDF in spring/summer. Irrigation depths affected Xaraés, Mombaça, and Estrela IVDMD, but did not affect their RP and NDF. Pioneiro presented higher RP and lower NDF, while Xaraés and Estrela presented higher and lower IVDMD, respectively.