Resumen

HERNANDEZ HERNANDEZ, Manuel et al. Forage yield and nutritional quality in Leucaena leucocephala and Megathyrsus maximus cv. Tanzania in an intensive silvopastoral system. Rev. mex. de cienc. pecuarias [online]. 2020, vol.11, n.1, pp.53-69.  Epub 11-Jun-2020. ISSN 2448-6698.  https://doi.org/10.22319/rmcp.v11i1.4565.

The biomass and nutritional value of Leucaena leucocephala cv. Cunningham (5,000 trees ha-1) and Megathyrsus maximus cv. Tanzania was assessed in a silvopastoral system in a tropical hot sub-humid climate in the rainy and dry seasons. Samplings were done from August-October 2014 (rainy) and March-April 2015 (dry). The treatments were harvests at 20-, 30-, 40- and 50-d intervals in both seasons, randomly assigned to twelve (24 m2) paddocks. The grass accounted for most of the total available forage in the silvopastoral system (80 vs 20 %). In both seasons, the association yielded more forage at the 50-d interval (5,300 kg DM ha-1 in the rainy season and 1,620 kg DM ha-1 in the dry season) (P<0.05). During the rainy season, crude protein (CP) in the tree forage was higher at the 50-d interval (22 %; P<0.05), but did not change over the intervals during the dry season (28 %; P>0.05); neutral detergent fiber (NDF) did not change over time (44 %; P>0.05) and acid detergent fiber (ADF) increased in the 50-d interval (25 %, P<0.05) but in vitro dry matter digestibility (IVDMD) decreased (49 %; P<0.05), regardless of season. Crude protein (10%; P<0.001) and IVDMD (58 %; P<0.03) of M. maximus remained high from the 20- to 40-d intervals, although in both seasons NDF and ADF fractions significantly increased after the 40-d interval. The evaluated silvopastoral system attains highest yield between the 40- and 50-d intervals. The highest nutritional quality of M. maximus was at 40 ds, after which the nutritional quality of L. leucocephala may compensate for the lost nutritional quality of the grass, regardless of season.

Palabras llave : Tree-grass association; Silvopastoral system; Nutritional quality; Season.