Effect of experimentally induced subchronic selenosis on thyroid hormones and biochemical indices in calves

The present investigation was performed to determine the effect of long-term administration of sodiumselenite on the biochemical indices and concentration of thyroid hormones in calves. Sodium selenitesolution was drenched at 0.1 and 0.25 mg per kg body weight for 12 weeks. Higher dose producedcharacteristic symptoms of selenosis whereas mild symptoms were observed with lower dose. The toxicsymptoms appeared when blood selenium level was 1.68 ± 0.13 μg per ml. There was a significant (P 0.05)increase in the activities of the aspartate aminotransferase, alkaline phosphatase, blood urea nitrogen andcreatinine levels in the treated animals. The repeated administration of sodium selenite resulted in asignificant p-value decline in thyroxine levels on the 10th week and increase in triiodothyronine on the 8thweek of treatment. The findings of the present study suggested that sodium selenite induced selenosis altersthyroid hormone levels in plasma.