Concentrations of selected toxic elements (cadmium, lead, mercury and arsenic) in ewe milk in dependence on lactation stage

Abstract

Biological investigations on ewes of Merinolandschaf breed (n = 10) were conducted by the 60th lactation day during the summer on pasture. Ewe milk sampling was carried out on the 2nd; 10th; 30th and 60th lactation day. An electrothermal technique was used to determine Cd and Pb concentrations in food and milk whereas As and Hg concentrations in food and milk were determined by a hydrid technique on an atomic absorption spectrophotometer. The investigation results indicate that concentrations of selected toxic elements in ewe milk varied in dependence on lactation stage. In colostrum (2nd lactation day) Cd and Pb (0.011 and 0.035 mg/kg)concentrations were significantly higher (P < 0.01) whereas As (0.011 mg/kg) concentrations were lower in comparison with milk on the 10th (Cd: 0.004; Pb: 0.022; As: 0.025 mg/kg), 30th (Cd: 0.005; Pb: 0.024; As: 0.028 mg/kg) and 60th (Cd: 0.006; Pb: 0.026; As: 0.029 mg/kg) lactation day. However, no significant differences (P > 0.05) were found in milk Hg concentration in relation to lactation stage (from 0.021 to 0.026 mg/kg). The selected toxic elements appeared to be present in ewe milk in very low concentrations.

Keywords

• ewe milk
• cadmium
• lead
• mercury
• arsenic
• lactation stage