Impact of the copper industry on the content of selected heavy metals and biochemical indicators in the blood of dairy cows

Abstract

The aim of the study was to compare the levels of selected blood parameters of dairy cattle in an area with copper industry (LGOM, area I, n = 21) and the Wroclaw agricultural suburban area (area II, n = 20). The concentration of heavy metals Cd, Cu, Pb and Zn (atomic absorption spectrometry method) and Hg (spectrometric method) was analysed in full blood. However, other parameters were determined in the blood serum: Ca, P (inorganic), Mg and Fe (photometric method), aspartate aminotransferase (AST) – an enzyme test in accordance with the recommendations of the IFCC, lactate dehydrogenase (LDH) – the test optimized according to the guidelines DGKC, gamma-glutamyl transferase (GGT) – kinetic photometric test. Biochemical parameters in blood serum were determined with the use of an automatic biochemical analyser type Pentra 400 and reagents of Horiba ABX (France). Furthermore, the analysis covered: the total antioxidant capacity (TAS) – colorimetric assay based on the ABTS and peroxidase reaction as well as the activity of glutathione reductase (GR) – colorimetric test based on the reduction of glutathione (GSSG) in the presence of NADPH. These parameters were determined with the use of the same analyser and commercial assays kit of Randox company. The Cd concentration in both areas was very low and did not exceed 1.65 µg/l, while the Pb concentration in the LGOM region was 0.021 mg/l and 0.031 mg/l in area II. The level of mercury in area I in both regions was similar (about 0.03 µg/l). The copper content was significantly higher in area I than in region II (1.67 mgl/l and 0.72 mg/l respectively), which indicates the possibility of industry impact on copper accumulation in cows. The Zn concentration was significantly lower in the LGOM region than in area II (2.50 mg/l) in contrast to Cu. The AST activity was significantly lower in area I (66.56 U/l) than in area II (75.49 U/l). Similar findings were reported with GGT activity (lower concentration in area I – 21.42 U/l). The LDH levels in animals were similar in both areas (2015.0 and 1976.2 U/l respectively), as were TAS (1.12 and 1.16 mmol/l) and GR (422.4 and 429.3 U/l). Mean activity of AST and GGT in cows were present in both areas, reaching ranges of the reference values, but the activity of LDH was significantly higher. There are no reference values for TAS and GR. Similar concentrations of Ca, Mg and Fe were noticed in both regions during the study, while the content of P was significantly higher in area I. The mean concentration of detected macroelements were in the reference ranges. The analysis proved that the cooper industry does not negatively affect the content of biochemical parameters in the blood of dairy cows.