Areas with high concentrations of selenium in the soil and forage produce beef with enhanced concentrations of selenium

Beef provides a significant portion of human dietary selenium (Se), and it is possible that modest portions of beef produced in areas with high-Se soi l and forage could provide the entire Recommended Dietary Allowance (RDA) f or Se. The present study has addressed the environmental conditions that re sulted in the production of high-Se beef. One hundred and thirty-eight cull cows were obtained from 21 ranches in five distinct geographic regions tha t, on the basis of soil parent material, reports of Se deficiency, and prev ious soil and forage Se surveys, were likely to have high or low Se concent rations in the soil. Grass and soil samples were taken from ranch sites, an d hair, whole blood, skeletal muscle, diaphragm muscle, and liver samples w ere obtained from the animals. Hair and whole blood samples were taken I da y prior to shipping. Selenium concentrations of all samples were determined by hydride generation atomic absorption spectroscopy. Geographic origin af fected Se content of all samples (p < 0.05). Selenium concentrations in soi l (r = 0.53; p < 0.01) and grass (r = 0.63; p < 0.01) were correlated to Se content of skeletal muscle. Selenium concentrations in whole blood, diaphr agm, hair, and liver also were significantly correlated to Se content of sk eletal muscle (p < 0.01). Cows that received Se in mineral supplements did not have significantly higher concentrations of Se in sampled tissues (p < 0.05). Results of this study suggest that the greatest source of variation in Se content of bovine skeletal muscle was the geographic region from whic h the beef originated and not production or management practices. Results a lso demonstrated that a 100 g serving of high-Se beef could provide 100% of the RDA for Se.