Selenium Requirements of Cattle and Means of Meeting Them

Abstract

It is becoming much easier to talk about selenium than it was and now one is more frequently faced with the problem of what to leave out, rather than what to put in. The literature on the element has expanded at a truly remarkable rate and no less than five books, completely devoted to it, have appeared in this country in the last dozen years. The first of these, a comprehensive text published in 1964 by Rosenfeld and Beath at the University of Wyoming entitled "Selenium: Geobotany, Biochemistry, Toxicity and Nutrition," successfully bridged the gap between the toxic and essential nutrient qualities of selenium. Two years later we assembled "Selenium in Biomedicine," which was the proceedings of an international symposium held at Oregon State University. In 1971 the Committee on Animal Nutrition of the National Research Council produced "Selenium in Nutrition" which was a summary of then-current knowledge. Ralph Zingaro at Texas A&M and Charles Cooper of Noranda Mines in Canada authored the text "Selenium" which was published by Van Nostrand in 1974 and the National Academy of Sciences came out this year with "Selenium: Medical and Biological Effects of Environmental Pollutants," which incidentally lists 845 reference citations.