nutritive value and in situ rumen degradability of marandu palisade grass at different locations within the pasture in a silvopastoral system with different babassu palm densities

The objective of this study was to evaluate the nutritive value and in situ rumen degradability of grass collected from different locations within the pasture in a silvopastoral system with different densities of trees. The silvopastoral system consisted of Urochloa (syn. Brachiaria) brizantha cv. Marandu and the babassu palm, Orbignya sp. (now: Attaleia speciosa). We used a completely randomized design with a 3 x 3 factorial arrangement for nutritional value (3 differently shaded locations and 3 palm tree densities) and a 3 x 3 x 3 factorial arrangement for dry matter (DM) disappearance (3 locations, 3 palm densities and 3 incubation times). There was no effect of location within the pasture nor of palm tree density on the concentrations of NDF, ADF, lignin, cellulose and hemicellulose. However, location influenced the concentrations of crude protein (CP) and DM, with highest CP in material grown in full sunlight. At all densities, DM disappearance at 96 h for pasture grown in full sunlight exceeded that for pasture grown in full shade. These factors need to be compounded with the possible depressant effect of trees on DM production of pasture when considering the benefits of silvopastoral systems.

Keywords: Digestibility, fiber, Northeast Brazil, protein, tree-grass associations, Urochloa  brizantha.