Cambios bromatológicos y estructurales en Megathyrsus maximum bajo cuatro arreglos silvopastoriles

The aim of this study was to compare the bromatological and structural behavior of Megathyrsus maximus (Poaceae) in four silvopastoral arrangement systems and a treeless prairie. Exclusion cages were used to evaluate four regrowth ages: 7, 14, 21 and 28 days. In each stage, the following were assessed: crude protein, neutral detergent fiber, acid detergent fiber and in situ degradability of dry matter (bromatological) and plant height, stem-leaf ratio and leaf width (structural). Crude protein in M. maximus was affected by silvopastoral arrangement (p < 0.05). The crude protein in Pasto and p-Arbust treatments were 2,42 % less than the mean of p-Arbor, p-Arbust-Arbor and p-Arbust-Arbor-M treatments. The neutral (65,16 %) and acid (37,30 %) detergent fibers were higher in the dry season (p < 0.05). The treatment affected (p < 0.05) plant height, stem-leaf ratio and leaf width, with highest value in p-Arbor (80,26 cm), Pasto (51,75:1 g) and p-Arbust-Arbor (2,73 cm), respectively. The interaction treatment, season and regrowth age affected plant height and leaf width. In the silvopastoral arrangement system with tree cover, plant height and leaf width were higher at 28 regrowth days in the dry season, compared with the Pasto and the p-Arbust treatments. In conclusion, the silvopastoral arrangement system influence the adaptative response of M. maximus, with an increase in crude protein and better response of the plant height and leaf width.