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Selenium Levels

Program Contact: Kathryn Hoogheem, Agriculture Extension Coordinator
(509) 684-2588 •

Selenium Levels in Much of the Northwest

Symptoms of Selenium Deficiency in Livestock – WSU Extension

Symptoms of Selenium Toxicity in Livestock – Colorado State University Extension

See the map below to see how Stevens County selenium levels compare with other areas in the Northwest.

Map showing average selenium levels in the Northwest – US Geological Survey

Selenium Toxicity from Forage

Selenium Toxicity can also be caused when animals eat certain plants which accumulate Selenium such as Locoweeds and Milkvetches.  For more information, please see the WSU document called Selected Poisonous Plants of the Northwest

Managing Selenium Levels in Forage and Livestock

Selenium level mapping in Stevens County soils is not of high enough resolution to tell us which soils have high levels and which are low.  The best way to know for sure about selenium levels in your soil, water, and forage is to have them tested in by a qualified lab.

Information on maximum allowable selenium levels for different livestock:  Selenium Toxicity for Ruminants, Paranoia or Precaution (McDowell)

Selecting a Soil, Forage, or Water Testing Lab

The Washington Animal Disease Diagnostic Lab (WADDl) in Pullman can test selenium levels in forage for you for a reasonable fee.  For more information, contact WADDL at:
Phone: 509-335-9696

For more information about other labs and testing check with the WA State Department of Ecology (see link below) or contact the Stevens County Extension office.

WA State department of Ecology web page dedicated to accredited testing labs for Washington State, including information on selecting a lab.

University of Idaho Analytic Sciences Lab (ASL)