Produtividade e valor nutricional do capim marandu em duas estratégias de manejo do pastejo

Abstract

The objective of this study was to evaluate two management strategies of Marandu grass (Urochloa brizantha cv. Marandu) grazing regarding structural, productive and qualitative parameters. The experiment was carried out at the Experimental Farm of Montes Claros State University, Campus Janaúba, MG. The experimental design used was randomized blocks, two pasture management strategies and eight replications. In the so- called rotational strategy, we assumed a pre-grazing height of 40 cm and a post grazing height of 24 cm, representing a 40% lowering of pre-grazing height. The strategy, called rotational management, was used 40 cm pre-grazing height and 10 cm post grazing, representing the maximum use of pasture. Data were subjected to analysis of variance and compared by the F test using SAS PROC GLM with α = 0.05. The rotational management presented higher dry matter production than the rotational pre (18.33%) and post-grazing (49.06%), which contributed to a 13.21% increase in pre-grazing forage density (P < 0.05). Potentially digestible dry matter yield was higher (21.3 and 39.6% before and after grazing, respectively) in the rotational strategy (P <0.05). Higher post-grazing dry green mass (45%) increased the residual crude protein content in rotational management. Both management strategies modified only fraction “a” of dry matter degradability, and did not influence the degradability of the pasture fibrous fraction. The strategy of management of rotational grazing provided an increase in forage dry matter yield, as a consequence of the larger number of grazing cycle, and can be used as a management strategy in marandu grass pastures.