Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/10/2000
Publication Date: N/A
Interpretive Summary: Because of the recent publicity of the multiple health benefits of selenium, there is much interest for increasing and/or supplementing Se intakes. Presently there are few options, other than taking commercially available supplements, for accomplishing this. Beef supplies the greatest portion of dietary selenium for any single food, and beef enriched in selenium may provide a dietary option to supplementing Se. This study collected soil and forage samples from ranches in various locations in the sate of North Dakota. Ranch locations were chosen because there was reason to believe that soil Se concentrations were either very high or low. Cull cattle were obtained from each ranch and slaughtered, and organ and meat samples were collected. Cattle from areas of low soil and forage Se had the lowest concentration of Se in the meat. A normal portion of beef from these animals would supply 1/2 to 1/3 of the Recommended Dietary Allowance (RDA) for Se. Conversely, cattle from areas with high concentrations of Se in soil and forage had the highest concentrations of selenium in the meat. A normal portion of beef from such cattle would supply more than the RDA for men and women. The health benefits of Se in beef are being investigated. Production of enhanced nutrient content in cattle from high-Se areas may be a means of enhancing the marketability and profitability of cattle from these ranches and farms.
Technical Abstract: Selenium (Se) is an essential trace element that provides many health benefits. Beef provides a significant portion of human dietary Se, and it is possible that modest portions of beef produced in areas with high-Se soil and forage could provide almost the entire Recommended Dietary Allowance (RDA). The present study has addressed the environmental conditions that result in the production of high-Se beef. 128 cull cows were obtained from twenty-one different ranches throughout the state of ND. Ranches were from five geographic regions that, based on soil parent material, reports of Se deficiency, and previous soil and forage Se surveys, were likely to have high or low Se concentrations in the soil. Grass and soil samples were taken during the growing season, and cattle were shipped to a commercial abattoir where skeletal muscle, diaphragm, liver, hair and whole blood samples were taken. Se concentrations of all samples were determined by hydride generation atomic absorption spectroscopy. Geographic origin affected Se content of all samples (p < 0.05). Se 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. Se concentrations in whole blood, diaphragm, hair, and liver also were significantly correlated to Se content of skeletal 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 is the geographic region where the beef originates, and not production or management practices. Results also suggest that a 100g serving of high-Se beef could provide 100% of the RDA for Se.