Selenium and iodine status of sheep in the Markaziprovince, Iran

The aim of this study was to provide preliminary quantitative information on selenium and iodine status of sheep in Markazi province, Iran. Selenium and iodine status of grazing sheep were measured for 57different flocks in 14 regions over one year. The districts were selected to represent major sheep growing areas in the province. Blood samples were collected from 2 to 3-year-old ewes during summer, autumn and winter. Samples were analyzed for blood glutathione peroxidase (GSHpx) activity and plasma inorganiciodine. There were significant differences between regions and seasonal differences in terms of blood GSHpxactivity and plasma inorganic iodine concentration (P 0.01). Low levels of GSHpx activity ( 60 IU/gHb)and plasma inorganic iodine ( 5 (mu)g/dl) in some regions or some seasons indicated the need for dietarysupplementation of these minerals.