determination of copper status of grazing sheep: seasonal influence

a study was conducted to determine the copper status of different classes of grazing sheep during twodifferent seasons on a farm located in southern punjab, pakistan. a complete free-choice supplement wasavailable to all animals throughout the year. soil, forage and blood plasma from animals were taken eighttimes during the year (2005) (four times in both summer and winter seasons). soil cu2+ was affected by the seasonal changes (p0.05) fluctuation in winter. it was adequate for ruminants’ requirements during both seasons. plasma cu2+ concentrations of all classes of sheep were significantly higher in winter than that in summer showing the seasonal changes (p