Elk (Cervus elaphus canadensis) preference for feeds varying in selenium concentration

Authors: Pfister, James; Davis, Thomas - Zane; HALL, JEFFERY - Utah State University; Stegelmeier, Bryan; Panter, Kip

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2015
Publication Date: 7/1/2015
Publication URL: http://handle.nal.usda.gov/10113/62880
Citation: Pfister, J.A., Davis, T.Z., Hall, J.O., Stegelmeier, B.L., Panter, K.E. 2015. Elk (Cervus elaphus canadensis) preference for feeds varying in selenium concentration. Journal of Animal Science. doi: 10.2527/jas2015-9008.

Interpretive Summary: Selenium-accumulator plants are reputed to be unpalatable to large ungulates. Elk (Cervus elaphus canadensis) populations in south-eastern Idaho overlap with populations of selenium-rich plants, but there is no information on the influence of plant Se concentration on elk dietary preferences. The objective of this study was to determine the preference of elk for pellets varying in Se concentrations. Seven yearling female elk (128 ± 5 kg) were purchased from a commercial elk farm in southeastern Idaho, and adapted to low-Se alfalfa pellets. Three feeding trials using pellets with predetermined Se concentrations were conducted. Alfalfa pellets were commercially made with the addition of Symphyotrichum ascendens (western aster) so that the pellets contained 0.4-, 5-, 20-, 50-, or 100- ppm Se. In trial 1, 5 Se-containing alfalfa pellets (0.4-, 5-, 20-, 50-, and 100-ppm Se) were offered for 10 days; trial 2 used 4 Se-containing alfalfa pellet choices (0.4-, 20-, 50-, and 100- ppm); trial 3 used 3 pellet choices (0.4-, 50-, and 100- ppm) for 6 days. In trial 1, consumption of the control pellets by elk was greater than each of the other pellet choices. Similarly consumption of the 5-ppm Se pellet was less than the control pellet but greater than the other Se-containing pellets. There were no differences in consumption of the 20, 50, or 100 ppm Se pellets. In trial 2 elk consumed more of the control pellet than the 20, 50, and 100 ppm Se pellets. Similarly, elk consumed more of the 20-ppm pellet than the 50- and 100-ppm Se pellets. There were no differences in elk consumption of the 50- and 100-ppm Se pellets. In trial 3, elk consumption of the control, 50-, and 100-ppm Se pellets differed from one another each day except that on day 1 and 2, where elk consumption of the 50- and 100-ppm Se pellets did not differ. Elk clearly discriminated against pellets with the highest Se concentrations when they were given pellets with differing Se concentrations. These results suggest that elk are not likely to select forages with high Se concentrations, particularly when high Se plants are present in a rangeland situation with numerous other forage choices.

Technical Abstract: Selenium-accumulator plants are reputed to be unpalatable to large ungulates. Elk (Cervus elaphus canadensis) populations in south-eastern Idaho overlap with populations of Se-rich plants, but there is no information on the influence of plant Se concentration on elk dietary preferences. The objective of this study was to determine, under controlled conditions, the preference of elk for feeds varying in Se concentrations. Seven yearling female elk (128 ± 5 kg) were purchased from a commercial elk farm in southeastern Idaho, and adapted to low-Se alfalfa pellets. Three feeding trials using pellets with predetermined Se concentrations were conducted. Alfalfa pellets were commercially made with the addition of Symphyotrichum ascendens (western aster) so that the pellets contained 0.4-, 5-, 20-, 50-, or 100- parts per million Se. In trial 1, 5 Se-containing alfalfa pellets (0.4-, 5-, 20-, 50-, and 100-ppm Se) were offered for 10 days; trial 2 used 4 Se-containing alfalfa pellet choices (0.4-, 20-, 50-, and 100- ppm); trial 3 used 3 pellet choices (0.4-, 50-, and 100- ppm) for 6 days. In trial 1, consumption of the control pellets by elk was greater than each of the other pellet choices (P < 0.001). Similarly consumption of the 5-ppm Se pellet differed from control pellet and all other Se-containing pellets (P < 0.0001). There were no differences (P > 0.50) in consumption of the 20, 50, or 100 ppm Se pellets. In trial 2 elk consumed more (P < 0.0001) of the control pellet than the 20, 50, and 100 ppm Se pellets. Similarly, elk consumed more (P < 0.0001) of the 20-ppm pellet than the 50- and 100-ppm Se pellets. There were no differences (P > 0.99) in elk consumption of the 50- and 100-ppm Se pellets. In trial 3, elk consumption of the control, 50-, and 100-ppm Se pellets differed (P < 0.03) from one another each day except that on d 1 and 2, where elk consumption of the 50- and 100-ppm Se pellets did not differ (P > 0.32). Elk clearly discriminated against pellets with the highest Se concentrations when they were given pellets with differing Se concentrations. These results suggest that elk are not likely to select forages with high Se concentrations, particularly when high Se plants are present in a rangeland situation with numerous other forage choices.