Relationship between selenium and selected heavy metals concentration in serum of cattle from a non-polluted area

The present study was undertaken to evaluate the concentration of selenium and selected heavy metals and their possible relationship in serum of 25 healthy lactating cows (Montbéliarde) reared in a non-polluted area, in the western part of Poland. Cadmium, lead, copper, and zinc concentrations were determined by inductively coupled plasma-atomic emission spectrometry and Se concentration was determined fluorimetrically. The content of Se, Zn, and Cu was 0.083 ± 0.026, 0.629 ± 0.413, and 0.152 ± 0.042 μg/mL, respectively. The presence of the Cd and Pb was found in all serum samples. The mean concentration of these metals was 0.0009 ± 0.0008 and 0.018 ± 0.016 μg/mL, respectively. Analysis of correlations between Se and toxic metals showed a negative and significant (P < 0.05) relationship between selenium concentration and lead and cadmium concentration in the serum of the animals studied, with correlation coefficients of r = -0.595 and r = -0.618, respectively. For copper and zinc, this relationship was also negative but not significant (r = -0.255 and r = -0.203). Our study demonstrated that the level of toxic metals decreased as serum selenium concentration increased. It seems necessary to conduct further research on the interactions between these elements in blood, serum, and target organs concomitantly with the determination of their intake.