The effects of different dietary concentrate levels on the net requirements of Ca, P, Mg, Na and potassium (K) were studied. Twenty-nine F1 Simental x Nellore bulls, averaging 17 months of age and initial LW of 354 kg, were used. Five animals were slaughtered at the beginning of the experiment as a reference and the remainders were allotted to a completely randomized design, according to the different dietary concentrate levels: 25.0, 37.50, 50,0, 62.5, and 75.0%. The animals were were full fed until a pre-established slaughter weight of 500 kg. The logarithm of mineral macroelement amounts were regressed on the logarithm of empty body weight (EBW). By deriving those regression equations, the net requirements for 1 kg EBW were found. The net requirements of Ca, P, Mg, Na and K for 1 kg EBW gain for an animal of 400 kg LW, using the overall equation, were, respectively: 10.33, 4.68, 0.30, 1.25, and 1.46 g. The mineral concentrations decreased, in the empty body weight, as the EBW increased
crossbred bovine; body composition; requirement; mineral; concentrate level; diet
