Energy supplementation for beef steers grazing tropical grass (Brachiaria brizantha, cv Marandu) managed under rotational system with different initial sward heights

Abstract

The project aims to evaluate the interaction between grazing management and supplementation, and the association between levels and sources of supplement in the rainy season on forage intake, feeding behavior, ruminal fermentation, microbial synthesis and blood parameters of Nellore. To this will be carried out three experiments in the area of Brachiaria brizantha cv. Marandu.In experiment 1 and 2 will be evaluated two times of arrival of animals , determined by the rate of light interception (LI) of the sward of 95% and 100%, which correspond to the cultivar Marandu, approximately 25 cm and 35 cm respectively. The average height of post-grazing residue will be reduced to 15 cm. Each entry times will be associated with two levels of energy supplementation of animals, corresponding to 0% (unsupplemented) and 0.3% BW (body weight) in experiment 1 and 0% (unsupplemented) and 0.6 % PC in Experiment 2.In the third experiment will be evaluated the effects of two sources (finely ground corn and citrus pulp) associated with two levels of supplementation (0.3 and 0.6% BW). In this experiment the pasture management will be accomplished with a single point of entry and exit of 25 and 15 cm respectively.