Effect of nitrogen fefitilization or legumes on liveweight gain of steers grazing guinea grass pastures

Abstract

The purpose of this trial was to evaluate the liveweight gam of steers grazing three types of Guinea grass pastures: grass alone (control), grass with nitrogen fertilization (100 kg/ha) and grass-legume mixture of perennial soybean (Neonoronia wightii Verdc) and centrosema Centrosema pubescens Benth). Twelve to fifteen-month old Guzerá male steers with 210kg of mean liveweight were used. The pasture-animal adjustment was realized by put-and-take method in a rotational grazing system. Animals were weighed and pasture samples were collected at 35 day intervals. During dry season, the daily and per hectare liveweight gain in the grass-legume mixture (0.264 kg/head/day and 85.73 kg/ha) were greater than the nitrogen fertilized (0.114 kg/head/day and 19.93 kg/ha) and the control (0.140 kg/head/day and 36.60 kg/ha). In a 15-month period nitrogen fertilized and grass-legume pastures showed no difference between liveweight gain per hectare, however these treatments were 16% upper when compared with the control.