This work aimed to determine the concentration of lead (Pb), cadmium (Cd), and chromium (Cr) in mineral feeds and supplements for cattle produced in the Mato Grosso State, Brazil. Three different lots of nine mineral supplements and eleven mineral feeds were collected, and the samples were prepared by wet decomposition and quantified by flame atomic absorption spectrometry. The limits of detection and quantification ranged from 0.18 to 0.64 mg kg-1 and 0.54 to 1.94 mg kg-1, respectively. Cr concentrations varied from lower than the LQI to 11.9 mg kg-1, and all samples presented values below the maximum recommended by the National Research Council (NRC) and European Union (EU). Cd concentrations varied from lower than the LQI to 6.1 mg kg-1, and 100 % of the mineral supplements and 60 % of the mineral feed showed Cd concentrations above the recommended by the EU (1.0 mg kg-1). Pb concentrations ranged from lower than the LQI to 33.1 mg kg-1, and 100 % of the mineral supplements and 90 % of the mineral feed showed Pb concentrations above the recommended by the EU (5.0 mg kg-1). All samples presented values below the maximum recommended by the NRC for Cd and Pb (10 and 100 mg kg-1, respectively). A large scatter of results was observed in the different samples for the three elements analyzed. This can be attributed to inhomogeneous impurity levels between batches of phosphate rocks used in the mineral feeds and supplements. A strict control of such mineral feeds and supplements should be implemented.
Keywords: Cadmium; Cattle; Chromium; Feeding; Food safety; Lead.