Altura do pasto para o diferimento de Capim-Marandu como determinante na produção de ovinos.

Abstract

The sward height for the deferral can modify the structure pasture during the dry season which may influence the performance of animais. Therefore, this study aimed to determine the effect of different heights of pasture of Brachiaria hrizanlha cv. Marandu for the deferral, about the structural characteristics of the pasture and the sheep performance. Two experiments were conducted in Uberlândia - Minas Gerais, Brazil, both in a split plot scheme in time and completely randomized design with three replications, evaluating combinations of four heights pasture (15, 25, 35 and 45 cm) at the beginning of the deferral period, corresponding to the portion, with grazing periods (beginning, middle and end), referring to the subplot. The beginning, middle and end of the grazing period correspond to the evaluations conducted on Ist, 45 0 and 90 0 days of grazing period, respectively. In the first experiment have been determined to forage mass, the percentage of morphological components of herbage mass, grazing simulation, the percentage of morphological components of the samples grazing simulation, the apparent selectivity index and performance of sheep. In the second experiment determined the height of the plant, extended plant height, the falling index, the number of vegetative and reproductive tillers, leaf arca index, mass living and dead leafblade and the mass of living stem and dead. Both experiments were repeated in two years and each variable was analyzed with 5% significance. There was interaction between height and grazing period for percentage and leaf blade dead in mass forage and sample grazing simulation, apparent selectivity index of living and dead leaf blade, and the percentage of live stem. The pastures 35; 45 and 25 have higher forage mass, but these pastures afforded worst animal performance compared to pasture 15 cm, The number of vegetative tillers (VET), the mass of living leaf blade and leaf arca index (LAI) were higher in deferred pasture with 15 cm. Pastures with greater height had the highest number of reproductive tillers (RET). The number of VET and RET, the mass of living leaf blade and live stem, and the LAI were higher at the beginning of the grazing period. The pasture ofBrachiaria hrizanlha cv. Marandu deferred to 15 cm showed better structure in the grazing period, as well as increased production of sheep during the winter in deferred grazing.