Evaluation of Sel-PlexTM as a Source of Selenium for Gestating and Lactating Beef Cows

The objective of this study was to compare the plasma selenium (Se) concentrations of cows and calves consuming inorganic Se vs an organic yeast Se source (Sel-PlexTM, Alltech, Inc., Nicholasville, KY). Mature cows were fed one of the two mineral treatments, which were offered freechoice with a targeted intake of 2 oz/ head/d. Each supplement contained equal recommended amounts of supplemental minerals. Cow body weight and body condition score were recorded on three sampling dates (Sept. ’05, Dec. ’05, March ’06), and blood samples were taken from randomly selected cows. Blood samples were also taken from calves born to these cows at the completion of the study. Mineral supplement containing Sel-PlexTM increased plasma Se concentration of both cows and their calves compared to inorganic Se sources. A decrease in mineral consumption by cows in each treatment resulted in less than adequate plasma Se concentrations in cows after calving. However, Sel-PlexTM treated cows still maintained greater plasma Se concentrations than Control cows following the initiation of the study.