| Abstract
| - Beef provides a significant portion of human dietary selenium (Se), and it is possible that modestportions of beef produced in areas with high-Se soil and forage could provide the entire RecommendedDietary Allowance (RDA) for Se. The present study has addressed the environmental conditionsthat resulted in the production of high-Se beef. One hundred and thirty-eight cull cows were obtainedfrom 21 ranches in five distinct geographic regions that, on the basis of soil parent material, reportsof Se deficiency, and previous soil and forage Se surveys, were likely to have high or low Seconcentrations in the soil. Grass and soil samples were taken from ranch sites, and hair, wholeblood, skeletal muscle, diaphragm muscle, and liver samples were obtained from the animals. Hairand whole blood samples were taken 1 day prior to shipping. Selenium concentrations of all sampleswere determined by hydride generation atomic absorption spectroscopy. Geographic origin affectedSe content of all samples (p< 0.05). Selenium concentrations in soil (r = 0.53; p< 0.01) and grass(r = 0.63; p< 0.01) were correlated to Se content of skeletal muscle. Selenium concentrations inwhole blood, diaphragm, hair, and liver also were significantly correlated to Se content of skeletalmuscle (p< 0.01). Cows that received Se in mineral supplements did not have significantly higherconcentrations of Se in sampled tissues (p> 0.05). Results of this study suggest that the greatestsource of variation in Se content of bovine skeletal muscle was the geographic region from whichthe beef originated and not production or management practices. Results also demonstrated that a100 g serving of high-Se beef could provide 100% of the RDA for Se. Keywords: Selenium; beef; soil
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