Desempenho de bovinos em pastagens de soja perene exclusiva e green panic fertilizado com nitrogênio

This experiment was conducted, during four consecutive years, to evaluate the performance of steers of Santa Gertrudes and Nelore breeds, grazing green panic fertilized or of perennial soybean pastures. The experiment was arranged in a completely randomized design with four replicates. The interaction breed/type of pasture was significant for animal liveweight gain. No difference was observed between animal breeds for the green panic pastures (331 e 303 g/anim./day, respectively for Nelore and Santa Gertrudes breeds). However, in the perennial soybean pastures, the gain for Santa Gertrudes was higher than for the Nelore (469 and 410 g/anim./ day, respectively). Both pastures showed a decrease in daily liveweight gain from the first to the last year of the trial (from 434 to 181 and from 544 to 375 g/anim/day, respectively for the green panic and perennial soybean pastures). The total liveweight gain during the total experiment period was higher for the perennial soybean than for the green panic pastures (1375 and 1047 kg/ha, respectively).(RA)