Selenium in cattle diseases and reproductive health

Selenium (Se) is a trace mineral critical for antioxidant activity, immune function, thyroid hormone conversion, fetal development, and reproduction. The goal is to emphasize the importance of preventing Se deficiency in cattle through year-round supplementation, soil analysis, and appropriate treatments to avoid conditions like white muscle disease, nutritional muscular dystrophy, and reproductive issues. Certain US regions have Se-deficient soils that may produce Se-deficient forages. In these areas, Se deficiency-related syndromes are common. Cattle require 0.1 mg/kg of Se for maintenance and more during pregnancy or lactation. Across age groups, deficiency results in various clinical manifestations, including white muscle disease in neonates, nutritional muscular dystrophy in calves and yearlings, and reproductive dysfunction in adults. Diagnosis involves soil and pasture analyses, Se concentrations in blood and serum, erythrocyte glutathione peroxidase activity, liver biopsies, or tissue recovery at slaughter or necropsy. Treatment is generally ineffective for neonates, but can be successful in older cattle, with injectable Se and ongoing supplementation being key. Prevention through year-round supplementation is crucial in Se-deficient regions.