Chemical composition of forage and selectivity by bovines of "sabiá" (Mimosa caesalpiniaefolia Benth.) in the rainy and dry seasons

This trial was carried out from June 1999 to March 2000 to evaluate the chemical composition of samples of sabia legume (Mimosa caesalpiniaefolia Benth.), with and without thorns, collected in the rainy and dry seasons and to compare the botanical composition of sabia pasture with that of the diet selected by the grazing animals. No significant difference was observed in chemical composition between samples of sabia with and without thorns. The mean values obtained in the rainy samples were: 26.45% drymatter (DM), 27.63% crude protein (CP), 44.39% neutral detergent fiber (NDF), 25.80% acid detergent fiber (ADF), 1.24% calcium (Ca), 0.22% phosphorus (P), 1.63% potassium (K) and 1.12% sodium (Na). In the dry period samples, the mean values observed were: 42.39% DM, 19.30% CP, 39.05% NDF, 21.83% ADF, 1.25% Ca, 0.15% P, 1.63% K and 0.27% Na. Considering the botanical composition, the rainy extrusa sample showed higher participation of sabia (83.1%) as compared to the dry period (12.3%). During the rainy period, the animals selected sabia in higher quantity while the hand plucked samples overestimated the dietary fiber fraction as compared to values for the extrusa samples.