Effects of diet and season on hormonal correlates of nutrition, reproduction and stress in female moose (Alces alces)

Understanding the interrelationships between nutrition and reproduction in herbivores such as moose (Alces alces) could provide wildlife managers with a tool to aid in management decisions. Historically, the impact of nutrition on moose reproduction has been quantified superficially via vegetation analysis and direct observations of cows preceding calving. This study investigated hormones linked to nutrition, reproduction and stress in captive moose. To accomplish this, I verified the accuracy of assays for several nutritional (leptin, ghrelin, insulin-like growth factor-1), stress (cortisol) and reproductive (estradiol and progesterone) hormones. I then monitored seasonal fluctuations of these hormones in captive female moose fed a maintenance diet over a 10-month period. Finally, I placed moose on two three-week dietary treatments representing high and low planes of nutrition and measured the response of these hormones to the different planes of nutrition. I found that several nutritional hormones in moose are influenced by season, but do not appear to be responsive to short-term changes in nutrition.