Changes of macromineral and trace element concentration in the blood of ewes during lactation period

The aim of the present research was to determine the changes in macromineral and trace element concentrations in ewes' blood during the lactation period. Thirty-six Travnik pramenka ewes at the average age of 3-5 years were included in research and they were evaluated at three stages of lactation: early stage (40 ± 5 days of lactation), medium stage (80 ± 5 days of lactation) and late stage (120 ± 5 days of lactation). In ewes' blood concentrations of macroelements (Ca, P, K, Na, Mg) and trace elements (Fe, Cu, Zn, Mo, Co, Se, Cd, As) were determined. The average concentrations of macroelements and trace elements in the blood of ewes during lactation were mostly within the reference values. Se concentrations in blood were close to the deficient ones, while concentrations of Cd and As were negligible. Concentration of Ca in blood was the lowest in the early lactation stage, higher in the late stage, and the highest in the medium stage (88.25 mg/l, 96.43 mg/l and 103.43 mg/l, respectively). A significant increase in the concentrations of Mg, Co and Cd and a significant decrease in the concentrations of Na, Fe, Cu, Zn, Mo and Se were found in blood with lactation progress. Significant correlations between the studied parameters were found, especially between macroelements (Ca : K, P : Na, K : Na, K : Mg). Positive correlations were found between some macroelements and trace elements (Ca : Co, Ca : Cd, K : Co, Na : Zn, Na : Se) and between trace elements (Fe : Cu, Cu : Zn, Cu : Mo, Cu : Se, Zn : Se, Mo : Se and Co : As). Negative correlations were found between Ca and Cu, Ca and Mo, P and Cd, K and Cu. Obtained results may help in monitoring the nutritional status and health of ewes during the lactation period, providing a clearer idea related to the supply of macrominerals and trace elements to ewes. Besides, results indicated that the environment of the farming area was not polluted with toxic elements.