Desempenho de vacas girolando mantidas em pastejo de tifton 85 irrigado ou sequeiro

Abstract

The aim of this study was to determine the stocking rates and milk production of crossbred Holstein x Zebu cows managed under irrigated or rainfed Tifton 85 pastures in Uberaba- MG. The statistical design adopted was completely randomized blocks with three repetitions per treatment, in a 2 x 10 factorial arrangement (2 treatments and 10 seasons). The average was compared using the Scott-Knott test with 5% probability (P<0.05). To evaluate animal performance, 11 lactating cows per treatment were used. The pasture was managed in a rotational grazing system with 21 and 35 days of grazing interval and 3 and 5 days of grazing in each paddock, in the rainy and dry seasons respectively. The stocking rate of the irrigated system was 4.6 UA.ha-1 and was superior (p<0.05) to the stocking rate of the rainfed system that was 2.2 UA.ha-1. There were no differences among the systems (p>0.05) for the average daily milk yield of the cows. In the irrigated system the average milk yield was 51.7 liters.ha-1.dia-1. With irrigation, a considerable intensification of the system was possible because it provided a superior stocking rate capacity compared to the rainfed system.