Selenium Poisoning in Livestock

ABSTRACT Selenium in certain soils may be taken up by plants in amounts to render them toxic. Seleniferous forage can be found in most of the western states. Intoxication of livestock by seleniferous plants has been classified as acute and chronic. Acute poisoning results from consumption,of plants having high levels of Se; chronic Se poisoning has been described in two forms— alkali disease and blind staggers. Alka- li disease is said to result from the consumption of seleniferous grains and grasses, and is manifest by loss of hair, lameness, and loss of weight. Blind staggers is slid to result from the consumption of Se indicator plants and is manifest by wandering, circling, loss of ability to swallow, and blindness. Some research casts doubt on the above classification of Se poisoning. Research using pigs (Sus scrofa domesticus) in- dicates that the source of Se does not alter the type of lesion or signs of poisoning observed. There are data available that suggest that blind staggers is not related to Se poisoning. Selenium (Se)-containing plants have long been recognized for their toxic