Selenium levels and productivity in three Oregon elk herds

Selenium (Se) is an essential dietary trace mineral and Se deficiency has been linked to decreased productivity in livestock and some species of wildlife. Productivity of elk (Cervus elaphus) in some areas of the Coast, Cascade, and Blue Mountains of Oregon is low or declining, yet the Se status of these herds is unknown. We compared liver Se levels and measures of elk productivity for 447 female elk collected from these 3 geographic regions of Oregon during controlled hunts held in December and January 1987-1993. Elk liver Se concentrations ranged 0.002 - 3.519 ppm, with 42% of the elk liver samples considered deficient by standards determined for cattle (liver Se ltoreq 0.120 ppm). Liver Se concentrations varied significantly between areas, and between some years within areas (P ltoreq 0.01). However, liver Se concentration was not related to age, body condition or conception dates of females gtoreq 1 year of age, and mean herd Se concentration was not related to post season calf:cow ratios, (P gtoreq 0.05). Liver Se was not significant in predicting the probability of pregnancy or lactation in females 3-13 years of age (P gtoreq 0.05). Therefore, we conclude that liver Se levels were not related to the elk productivity parameters we measured. However, liver Se may not be the most appropriate measure of an animal's Se status, because it does not represent a measure of the bioactive form of Se. Instead, we recommend measuring levels of Se in bloodStussy et al "Selenium levels and productivity in three Oregon elk herds." Northwest Science. 2000; 74(2): 97-10