Selenium accumulation in captive american kestrels (falco sparverius) fed selenomethionine and naturally incorporated selenium

Abstract

Male-female pairs of kestrels were maintained for 11 weeks on diets Containing 5 or 9 ppm selenium (Se) (dry weight) as seleno-L-methionine, or naturally incorporated Se in the form of mammals collected at Kesterson Reservoir, CA, USA. Selenium concentrations in blood and excreta of male and female kestrels within groups were similar. Near-maximal mean Se concentrations in blood were observed after the 5th week of treatment in the seleno-L-methionine-treated kestrels, and an approximately 1:1 ratio was observed between maximal blood concentrations and dietary concentrations. All treatment groups exhibited reduction of Se concentration in excreta, but not in blood, to baseline' values 4 weeks after treatment ended. No birds were observed to exhibit signs of general illness or Se toxicity during the study.