Beef cattle performance on signal grass pastures deferred and fertilized with nitrogen

Abstract

The effect of four nitrogen levels (0, 40, 80 and 120kg N ha-1), applied before deferment on the beef cattle production and structural variables on Urochloa decumbens (signal grass) were assessed from January to October 2012 and from January to September 2013. A randomized block design with three replicates was adopted, in an arrangement of repeated measures in time (grazing period). An interaction effect between nitrogen level and grazing period was observed on extended-plant height and herbage mass. As the nitrogen levels were increased, extended-plant height, herbage mass, total herbage allowance, and efficiency of conversion of fertilizer into herbage were increased. Throughout the grazing period, pasture height, extended-plant height, percentage of leaves, herbage and morphological components allowance, and percentages of leaves and stems in the herbage apparently selected by the animal decreased. Nitrogen levels had no effect on average daily gain or gain per area in the first year. A fixed deferment period with increasing levels of nitrogen fertilization on signal grass pastures does not influence the average daily gain per animal, reduces the efficiency of the nitrogen fertilizer and negatively changes the structural characteristics of the pasture.

Signal Grass Deferred Pastures Fertilized with Nitrogen or Intercropped with Calopo

“…Nitrogen fertilization before pasture deferment can improve the forage mass and its chemical composition. In a study of deferred signal grass [5], the authors observed an increase in forage mass and an improvement in structural characteristics as the nitrogen dose increased, while increases in mass and allowance forage were identified [6]. However, nitrogen fertilization considerably increases the costs of production, as the synthesis of fertilizers requires sources of fossil fuel, and most nitrogen inputs are currently imported [7].…”