Produção e valor nutritivo de gramíneas do gênero Cynodon em diferentes idades ao corte durante o ano

Abstract

The aim of this experiment was to estimate production, leaf/stem ratio and nutritive value (NV) of three Cynodon gender cultivars (Coastcross, Tifton 44 and Tifton 85), harvested at 21, 42 and 63 days, during spring and summer; 42, 63 and 84 days during fall; 63 and 84 days during winter. The experimental design was split splot, with three replications. Age harvest was evaluated by regression and the models were chosen based on identity analysis. Older harvest age increased (P < 0.05) dry matter (DM) production, neutral detergent fiber (NDF) and acid detergent fiber (ADF), for all seasons. Leaf/stem ratio (L/S), crude protein (CP), metabolizable energy (ME) estimated, dry matter in vitro digestibility (DMIVD) and organic matter in vitro digestibility (OMIVD) were negatively affected (p < 0.05). However, L/S and CP were not affected (P > 0.05) by increasing forage harvest age in winter. Independently of the season, all cultivars showed similar production and NV. Considering the results for chemical composition and ME estimated, older harvest ages (63 and 84 days) are not recommended, because there was a NV decrease for all cultivars, harvest ages between 21 and 42 days being thus recommended.