Estrutura do pasto e desempenho de ovinos em capim-massai na época seca em resposta ao manejo do período das águas

Abstract

The objective of this study was to evaluate the canopy structure and performance of sheep raised on massai grass during the dry season in response to the management adopted during the wet season. The treatments consisted of two targets of light interception (90 and 95%) and two post-grazing heights (15 and 25 cm) in a 2 x 2 factorial scheme. Pastures were managed during the wet season, while continuous stocking was used during the dry season. The following pasture characteristics were evaluated: canopy height, forage mass, leaf blade, stem and dead matter mass, leaf blade:stem ratio, crude protein, neutral detergent fiber, acid detergent fiber and acid detergent lignin content, and dead matter of morphological components. Sixteen sheep with an initial body weight of 19 ± 4.7 kg were used and average daily gain, weight gain per hectare and stocking rate were evaluated. The interactions between sources of variation were not significant for any of the variables. Post-grazing heights modified total forage and dead matter mass in the dry season, with the highest values of 2912.5 and 1840.9 kg/ha of dry matter, respectively, being observed when the pastures were managed at 25 cm during the wet season. There was no effect of the management adopted during the wet season on the chemical composition of leaf blades during the dry season. The management adopted during the wet season exerted no effect on animal performance during the dry season. Pasture management to a post-grazing height of 25 cm during the wet season, irrespective of pre-grazing target (90% or 95% light interception), maintains the most adequate forage structure during the dry season. The management adopted during the wet season did not