Thirty-five Nellore bulls were used to determine the effect of supplementation of 2 levels and 2 sources of copper (organic and inorganic) on performance, copper status in the body and ruminal parameters. The 5 treatments used were: 1) Control (C) - without copper supplementation; 2) 10 mg of Cu / kg of DM (as Cu sulfate; CuI10), 3) 40 mg of Cu/ kg of DM (as Cu sulfate; CuI40); 4) 10 mg of Cu/ kg of DM (as Cu proteinate; CuO10); 5) 40 mg of Cu / kg of DM (as Cu proteinate; CuO40), for a period of 84 d. Body weight and blood samples were collected every 28 d for copper and ceruloplasmin analysis. At slaughter samples collected consisted of rumen fluid for short chain volatile fatty acids (VFA) determinations and ammonia nitrogen, also liver and muscle samples were collected for copper analysis. The experimental design was a completely randomized design with 7 replicates. Data were analyzed using PROC GLM of SAS. Means were compared by contrasts at a 5% significance level. There were no significant effects of copper level in the muscle (4.45, 4.24, 4.82, 4.21 and 5.79 with 1.05 of SEM for C, I10, I40, O10 and O40, respectively) and copper concentrations in the serum (0.873, 0.885, 0.967, 0.896 and 0.901 with 0.03 of SEM for C, I10, I40, O10 and O40, respectively). However, there was a quadratic effect for supplementation with different sources and Cu levels, with respect to time. The Cu concentration in the liver was higher (P < 0.05) in animals supplemented with CuO40 with the values 237.3, 435.7, 607.5, 466.6 and 765.4 with 48.71 of SEM for C, I10, I40, O10 and O40, respectively. The CuI40 treatment showed the highest serum activity of ceruloplasmin (P < 0.05). There was no significant effect for feed efficiency between treatments. The ruminal pH, VFA and ammonia nitrogen were not affected by treatments. In general, copper supplementation altered the Cu “status” in the animal with a greater accumulation of Cu in the liver of animals receiving the CuO40. These results show that feeding higher amounts of organic Cu make the mineral more bioavailable.