Avaliação da Folha e do Colmo de Topo e Base de Perfilhos de Três Gramíneas Forrageiras. 1. Digestibilidade in vitro e Composição Química

Abstract

The degree of a simple linear correlation among the in vitro dry matter disappearance (IVDMD) and chemical composition of the leaf blades and sheath, and stems, sampled from the top and bottom tillers of dwarf elefantgrass (Pennisetum purpureum, Schumach cv. Mott, setariagrass (Setaria anceps, Stapf ex Massey cv. Kazungula) and jaraguagrass (Hyparrhenia rufa, Nees Stapf), was evaluated. A gradient pattern was observed for IVDMD, crude protein (CP) and cell wall (NDF) along the tiller profiles and difference among the tiller fractions. The leaves inserted on the top of tiller showed higher CP content and digestibility, despite of the higher NDF content than those leaves inserted on the bottom level of the tiller. The leaf blades showed a relative high IVDMD, CP and NDF than leaf sheath. No correlation was observed among the chemical components and IVDMD of the top leaf blades of the tiller. Only the lignin content showed a significant correlation (r = -0.53) with the IVDMD, when the top and bottom leaf blades were grouped. The neutral detergent fiber, acid detergent fiber, crude protein and lignin showed correlation with the IVDMD of bottom leaf blades, leaf sheath and stem.