FORAGE YIELD, QUALITY AND UTILIZATION EFFICIENCY ON NATIVE PASTURES UNDER DIFFERENT STOCKING RATES AND SEASONS OF THE YEAR IN THE MEXICAN HUMID TROPIC

Abstract

This study aimed to evaluate the effect of season of the year (SY) and stocking rate (SR) on forage yield, utilization efficiency, development of plant components, crude protein (CP), cell wall content (CWC), ruminal degradation of dry matter (DM), acid detergent fiber (ADF) and neutral detergent fiber (NDF) of native grasses, in two consecutive years, in Veracruz, Mexico. Treatments included 2, 3 and 4 cows ha-1 during the rainy, windy and dry seasons. For each SR, 10 Holstein x Zebu cows were used in 10 paddocks of 0.5, 0.33 and 0.25 ha for SR 2, 3 and 4 cows ha-1, respectively. Each paddock was grazed for three days and had a rest period of 27 days. A randomized design with two replications was used. Stocking rate did not affect forage yield (6171 kg DM ha-1), CP of leaves (9.9 %) and stems (7.2 %), CWC, ruminal degradation of DM of leaves (69.8 %) and stems (70.7 %), nor NDF of leaves (69.6 %) and stems (73.5 %), whereas SY did affect these variables. The SY was the main factor affecting forage yield and nutritive quality. The density and length of stems, and the length of leaves were higher at a lower SR in the rainy season.