Performance of nellore heifers on deferred urochloa brizantha pasture fertilized with nitrogen

The aim of this study was to evaluate the effects of different levels of nitrogen in deferred Brachiaria (Syn.Urochloa) brizantha cv. Marandu pastures on the intake, digestibility, and performance of Nellore heifers. A completely randomized design was adopted, with four treatments (nitrogen levels) and four replicates (number of fertilized paddocks). Initially, 48 Nellore heifers with an average age of 8 months and with an initial body weight of 179 kg were distributed at the rate of three animals per paddock into all treatments in a continuous grazing system with variable stocking rate. The intake and digestibility of crude protein and total digestible nutrients increased linearly with the nitrogen levels. The application of nitrogen had a quadratic effect on weight gain per area and weight gain per area per day, with maxima at 99 kg N.ha–1 for both gains. The intake and digestibility of nutrients are crucial to the animal performance, and fertilized deferred pastures provide higher intake and digestibility of crude protein and total digestible nutrients. Animal performance is better in the initial period of grazing due to the positive effects of nitrogen fertilization on forage.