Frecuencia de cosecha sobre la producción, valor nutricional y crecimiento del pasto estrella africana (Cynodon nlemfuensis Vanderyst)

The frequency of defoliation impacts the recovery, and productivity of forage plants. The objective of this study was to evaluate the type of growth, forage yield, and nutritive value of African Stargrass (Cynodon nlemfuensis Vanderyst) at different frequencies of harvest to determine the range of time to optimize its utilization. The study was conducted from June through December 2019 at the Alfredo Volio Mata Dairy Cattle Experimental Station (EEAVM), in Cartago, Costa Rica. Five harvest frequencies (14, 21, 28, 35 and 42 days of regrowth) were used to assess morphological traits, forage yield, and nutritive value. Nutritional value was evaluated using cell wall structural components (FND, FAD and lignin), intracellular components (DM, CP, EE, Ash), dry matter digestibility (DIVDM), neutral detergent fiber digestibility (DIFND) and energy content (NEL, Mcal kg-1 DM). Lower frequency of harvest (more days of regrowth) yielded greater proportions of stems and senescent material. Forage yield increased significantly with lower frequency. The variables of nutritive value (DM (17.80-20.87 %), CP (15.38 - 18.10 %), EE (3.39 - 3.93 %), FND (59.11 - 61.78 %), FAD (27.90 - 30.11 %), NEL (1.38 - 1.44 Mcal kg-1 DM) did not show significant differences with the harvest frequencies evaluated. The integrated analysis of variables shows that harvesting of up to 42 days regrowth allowed greater biomass production with adequate nutritional value to meet the requirements of ruminant animals without affecting pasture recovery and development. Besides nutritive value, Stargrass harvested at 20 cm height and 7 leaves per shoot can be used as indicators to optimize the point for harvest.