Tropical and Subtropical Agroecosystems (Nov 2011)
FORAGE PRODUCTIVITY IN AGROECOSYSTEMS USING TRADITIONAL AND ROTATIONAL CATTLE GRAZING IN PASO DE OVEJAS, VERACRUZ, MEXICO
Abstract
Forage biomass and chemical composition of Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs were assessed in monoculture (P) or associated with trees of Guazuma ulmifolia Lam. (PGu) or Gliricidia sepium (Jacq.) Kunth ex Walp (PGs), under traditional (TG) or rotational (RG) cattle grazing regimes, by season of the year (windy: October-February, dry: March-June, and rainy: July-September) and annually. Annual forage production (kg DM ha-1) under RG and TG was 8049±586 and 4170±319, respectively; 5441±2225 in P-TG, 2022±82 in PGs-TG, 12326±2094 in PGu-TG, 9612±1331 in PGs-RG, and 7976±737 in PGu-RG. Gliricidia sepium produced 1448±2 and 1660±3 kg DM ha-1 year-1 under PGs-TG and PGs-RG, respectively. Forage yield across plant associations and grazing regimes was higher in the rainy season (5333.6±56.7 kg DM ha-1), and decreased in the windy (2462±349.0 kg DM ha-1) and dry seasons (252.9±2 kg DM ha-1). The PGu system had the highest crude protein content annually (21.8 %) and by season (23.1 %, windy), and also showed the least neutral detergent fiber content during the year (55.2 %) and by season (55.2 %, rainy). Biomass production and chemical composition of M. maximus in monoculture or associated with G. ulmifolia and G. sepium can be increased by modifying the traditional grazing regimes to a more intensive rotational system during the growth period of the year.
