Agronomic Traits, Physiological Parameters, Chemical Composition, and In Vitro Digestibility of <i>Urochloa Brizantha</i> Cv. Piatã, <i>Megathyrsus Maximus</i> Cv. Zuri and <i>Megathyrsus Maximus</i> Cv. Tamani in Silvopastoral Systems

Urochloa species are widely used in silvopastoral systems (SPS), but production losses highlight the need for more productive forages. This study evaluated agronomic, physiological, chemical composition, and in vitro digestibility responses of Urochloa brizantha cv. Piatã and Megathyrsus maximus cvs. Zuri and Tamani in SPS and monoculture (MONO). Forages were sown in MONO or SPS with 166 eucalyptus trees/ha. Nine plots were established per system, giving three replicates per cultivar. Forage accumulation and biomass were 31.8% (35.2 vs. 51.6 kg DM/ha/day) and 32.0% (5735 vs. 8428 kg DM/ha) higher in MONO than SPS. Biomass was 34.1% higher in M. maximus cv. Zuri than U. brizantha cv. Piatã. The leaf/stem ratio was 52.3% lower (3.18 vs. 6.66) in U. brizantha cv. Piatã than M. maximus cultivars. Intercellular carbon was 16.1% (180 vs. 155 µmol CO 2 /m 2 /s) higher in MONO, while water use efficiency was 67.8% lower than in SPS. Megathyrsus maximus cv. Tamani had the highest crude protein (CP) in both systems, and CP in cvs. Tamani and Zuri was 6.43% (140 vs. 149 g DM/kg) and 18.0% (111 vs. 131 g DM/kg) higher in SPS than MONO. Although shading reduces M. maximus production, these cultivars can increase animal production compared with Urochloa in SPS.