CONCENTRATION OF SELENIUM IN SOIL, PASTURE, BLOOD AND WOOL OF SHEEP

Investigations have been conducted on Slavonia during a three year period on six locations, two per each year during June (in the first year = Vinkovci and Beli Manastir; in the second year = Valpovo and Djakovo; in the third year Slatina and Donji Miholjac). Six samples from the soil, pasture and sheep wool, as well as 15 sheep blood samples were taken from each locality. There was a deficit of selenium content in the soil on four locations in the second and third year (0.18; 0.14; 0.10 and 0.07 mg/kg) and an adequate content on locations Vinkovci and Beli Manastir in the first year (0.98 and 0.71 mg/kg). The locality Valpovo was characterized by the highest selenium concentration in pasture, blood and wool of sheep, as well as by the lowest blood enzymes activities (ALT, AST, CK, LDH) when compared to other locations. Selenium concentration in pasture was under the critical range on all locations (from 0.006 to 0.03 mg/kg DM), except the locality Valpovo in the second year (0.05 mg/kg DM). Serum selenium concentrations (from 0.035 to 0.082 mg/L) on all locations were below the adequate range for adult sheep and differed among locations. Activities of enzymes in the blood of sheep (AST: 3.59, CK: 4.93 and LDH: 6.87 μkat/L) showed severe selenium deficiency. Selenium concentrations in the wool were under the critical level on all locations (from <0.0002 to 0.06 mg/kg). The results regarding selenium in wool showed that, apart from blood selenium and activities of plasma enzymes (AST, CK, LDH), wool should also be taken in account as a selenium status indicator.