Toxicosis in Pigs Fed Selenium-Accumulating Astragalus Plant Species or Sodium Selenate

The study investigated the effects of high selenium diets on pigs, using Astragalus praelongus, A bisulcatus, and sodium selenate as selenium sources. Each group consisted of 5 pigs, with 10 control pigs on a low selenium diet. Over 9 weeks, all selenium-fed pigs exhibited weight and hair loss, with additional symptoms like cracked hooves and inflamed coronary bands in sodium selenate-fed pigs. Blood tests showed increased serum aspartate transaminase activities in Astragalus-fed pigs, and changes in other enzyme activities across all selenium-fed groups. Selenium concentrations in tissues and fluids were significantly higher in treated pigs compared to controls. All selenium-fed pigs developed poliomalacia of the spinal cord and brain stem, with the increase in AST activity in Astragalus-fed pigs linked to swainsonine in the plants.