Toano milkvetch (Astragalus toanus Jones) synthesizes the beta-D-glucoside of 3-nitro-1-propanol (miserotoxin), a highly toxic aliphatic nitro compound, and also accumulates toxic levels of selenium. The toxicity of Toano milkvetch to 1-week-old chicks was compared with Wasatch milkvetch [Astragalus miser var. oblongifolius (Rydb.) Cronq.], which contains only miserotoxin but does not accumulate selenium; stinking milkvetch (Astragalus praelongus Sheld.), which accumulates selenium but does not contain miserotoxin; and a combination of Wasatch milkvetch and stinking milkvetch. The LD50 for chicks fed Toano milkvetch was 67.8 mg NO2/kg plus 2.7 mg Se/kg of body weight. The LD50 for Wasatch milkvetch was 105 mg NO2/kg and for stinking milkvetch 5.9 mg Se/kg. The LD50s of a combination of Wasatch milkvetch and stinking milkvetch were 66.1 mg NO2/kg and 2.7 mg Se/kg. When miserotoxin and selenium were fed together, either in Toano milkvetch or the Wasatch-stinking milkvetch combination, the LD50 for each compound was significantly lower than when they were fed separately. If seleniferous and nitro-bearing species grow sympatrically, livestock might be poisoned at lower concentrations of the individual toxic compounds if they grazed both species. This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.