Suplementação da dieta de novilhos de três grupos genéticos em pastagem de Brachiaria brizantha cv. Marandu

Supplementation of the diets of three genetic groups of crossbred steers on Brachiaria brizantha cv. Marandu pasture. This trial was carried out to study the effects of supplementation level on performance of steers from different genetic groups (Nellore x Red Angus (NR), Nellore (NL) and Holstein crossbred (MH), and three experimental periods. The performance data for first period were analyzed according to randomized block (RB) design, with 3 treatments ((NR, NL and MH)) and 3 blocks. In second period, the RB design used with 3 x 3 factorial design, and 3 blocks. Factor A determined the group (NL and MH) and factor B the supplementation levels (0.2, 0.6 and 1% LW). In third period, the data were evaluated according to completely randomized design, with 2 x 3 factorial design. Factor A determined the group and factor B, three levels of supplementation. In the first, higher weight gain (p < 0.05) was observed for NR (0.79 kg day -1 ) compared to MH and NL (0.73 and 0.61 kg day -1 ). The concentrate intake varied for N. NR showed higher (p < 0.05) WG (0.91 kg day -1 ) compared to NL (0.75 kg day -1 ) and MH (0.76 kg day -1 ). The levels of supplements influenced (p < 0.05) WG (0.68, 0.81 and 0.92 referring to levels of 0.2, 0.6 and 1.0% LW). In third period, MH presented greater WG < 0.05) (0.895 kg day -1 ). No difference was verified on animals with 0.8 and 1.2% LW, with WG of 0.92 and 0.82 kg day -1 .