The objective of this trial was to evaluate the effects of different levels of supplementation on performance of grazing steers in the growing phase. The experiment was carried from March to November 2003. Fifty-five steers averaging 10 months old and initial body weight of 226 kg were assigned to a completely randomized design. The treatments were as follows: control (mineral salt) and supplements fed at different levels (0.125, 0.25, 0.50, and 1.0% body weight/animal/day) and contained corn and soybean meal formulated to yield 24% crude protein. The control group intaked 70 g/day and averaged daily gain of 0.28 kg. The control group showed protein content below the threshold value, which did not meet gain requirements. Animals fed other treatments averaged daily gain of 0.51, 0.58, 0.68 and 0.72 kg/day, with the supplement conversion of 1.48, 1.56, 2.67 and 4.43, during the transition time, and 1.52, 3.17, 5.29 and 10.19, during the dry season, for 0.12; 0.25; 0.5 and 1.0% BW. The supplementation provided higher values of weight gain at the levels of 0.5% and 1.0%, with higher efficiency at the levels of 0.125 and 0.25%.
corn; daily gain; efficiency of the supplement; protein supplementation; soybean meal
