Animal Performance in Pastures of Panicum maximum cv. IPR 86 Fertilized with Nitrogen

Animal Performance in Pastures of Panicum maximum cv. IPR 86 Fertilized with Nitrogen

The experiment was carried out at the Experimental Station of the IAPAR in Paranavaí– PR, Brazil, from October 1998 to May 1999 to evaluate the response of crossbred steers grazing pastures of Panicum maximum cv. IPR 86 fertilized with four doses of N (0; 150; 300 and 450 kg.ha^-1.year). The grass was grazed according to a rotational grazing system with grazing cycles (GCs) of 40 days (grazing period of 5 days and rest period of 35 days). It was used a randomized complete block design, with split-plots, and two replications per treatment, being the N-doses studied in the main plots and the GCs in the sub-plots. The availability of green leaf-blades increased with the increase of N-doses, resulting in 4.09; 8.18; 11.18; and 13.92 steers.ha^-1.day^-1 and daily LWG of 2.73; 5.25; 7.40; and 9.24 kg.ha^-1 when the pastures were fertilized with 0; 150; 300 and 450 kg N.ha^-1, respectively. The efficiency of N-utilization was 3.35; 3.11; and 2.89 kg LWG kg.N^-1 when the pastures were fertilized with 150; 300; and 450 kg N.ha^-1, respectively.