• Arsenic interacts with many other dietary factors, resulting in either increased or decreased toxicity.
• Livestock should not be fed water containing more than 10 mg Ba21/L even for short periods. Until there are better data, it is impossible to make any recommendations regarding chronic exposure.
• The effects of fluoride in feedstuffs and water are additive; what counts is the total dose of biologically available fluoride ion ingested by the animal.
Water is the most important nutrient for rangeland livestock. However, competition with municipalities, industry, and other water users often results in grazing livestock being forced to use water supplies that are less than perfect. Surface water in western rangleands are often contaminated by mineral extraction, irrigation runoff and other human activities. Mineral contaminants in drinking water are additive with similar contaminants in feedstuffs. The goal of this article is to provide producers and veterinarians with the basic background to make informed decisions about whether a given water supply is “safe” for livestock.
Water quality: Arsenic, Barium, Fluoride, Molybdenum, Selenium
The author is with the Department of Veterinary Sciences, College of Agriculture, University of Wyoming, 2852 Riverside, Laramie, WY 82070, USA