Effects of Seleniferous Grains and Inorganic Selenium on Tissue and Blood Composition and Growth Performance of Rats and Swine

Abstract

Two experiments were conducted to determine the effect of varying dietary selenium (Se) levels and Se source on growing swine. In Exp. 1, seleniferous wheat and oats were used to formulate diets containing .47, 2.58, 5.60 or 8.40 µg/g organic Se. Dietary Se level had no effect on pig performance during the 6-wk experiment as measured by daily gain, daily feed intake or feed/gain. Blood composition and enzyme activity were not affected by dietary treatment. Selenium concentrations of blood, hair, liver, kidney, heart, spleen and diaphragm muscle were increased linearly (P<.01) as dietary Se increased. In addition, liver weight as a percentage of body weight was increased linearly (P<.01) as dietary Se level increased. No signs of chronic Se poisoning were observed. Dietary treatments in Exp. 2 were similar to Exp. 1 with the exception that sodium selenite was utilized as the Se source and the diets were fed for 17 wk. Inorganic Se levels of .54, 2.63, 5.69 or 8.3 3 µg/g had no effect on pig performance as measured by daily gain, daily feed intake or feed/gain. Selenium concentrations of blood, hair, liver, kidney, spleen and diaphragm muscle were significantly increased as dietary Se level increased. Liver weight as a percentage of body weight was increased at the two highest dietary Se levels. Blood glutathione peroxidase activity was significantly increased by dietary treatment, while other blood variables were not affected. No signs of chronic Se poisoning were observed. These results suggest that the toxic level of Se for growing pigs fed diets of this type is greater than 8.33 µg/g regardless of the Se source. The data for rats, while generally indicating the same degree of effects as the data for swine, suggest that rats are more susceptible to chronic poisoning by selenium. Copyright © 1984. American Society of Animal Science . Copyright 1984 by American Society of Animal Science