The Iron, Copper and Selenium status of grazing ewe in Semirom rangelands

The present study reports the iron, copper and selenium status and their variations in grazing ewes in Semirom rangelangs in spring and summer of 2008.During 4 months of year (from May to September) the Semirom rangelands were grazed by Torki-Ghashghaii sheep.According the plant cover of Semirom, 7 major sites, that were the representative of area and in every site, one nomad sheep herd was selected. Blood samples were taken from the jugular vein of 6-7 non-pregnant and healthy ewes in each herd in 3 different times of grazing season (Early, middle and late time of grazing season). Ewes were raised under range conditions without any dietary supplementation. The concentration of iron and copper was detected in serum and selenium (Glutathione peroxidase activity) in whole blood by diagnostic laboratory kits.The results of this study indicated that, Fe, Cu and Se concentration in serum vary through 3 different times of grazing season (P0.01) but except the Fe that it's concentration in serum (2.139±0.049 mg/L) was significantly lower than critical level, the levels of them were in the recommended concentrations in the serum of sheep blood in the first time of grazing season.Fe concentration was 1.677±0.047 mg/L in the middle time and 2.139±0.049 mg/L in the late time of grazing season.Although the levels of copper and selenium were agree well with the existing literature data, but from the early to late time of grazing season increased significantly (P0.01).Copper concentration in the serum from the early to late time of grazing season of grazing season was 2.124±0.088, 1.885±0.056, 1.718±0.033 mg/L and selenium concentration in whole blood was 0.189±0.008, 0.235±0.008 and 0.275±0.009 mg/L respectivly.Commonly the Ghashghaii nomads spend 8 month of every year in winter quarters and 4 month in summer quarters and the gestation and lactation of lambs take place in winter quarters.According of this study, the deficiency of iron, copper and selenium are not confirmed, therefore the application of these trace element supplements need further investigation.