A diet supplement for captive wild ruminants.

Nutritional husbandry of captive wild ruminants often requires feeding these animals a supplemental diet to enhance their health, reproductive performance, and productivity. Although supplemental diets for wild ruminants are commercially available, few have been evaluated in controlled intake and digestion trials. Voluntary intake, digestive efficiency, nitrogen retention, and gross energy utilization of pronghorn (Antilocapra americana), mule deer (Odocoileus hemionus), mountain sheep (Ovis canadensis), mountain goats (Oreamnos americanus), and wapiti (Cervus elaphus) consuming a high-energy, high-protein pelleted supplement were compared. Voluntary intake of dry matter, energy, and nitrogen were similar (P > 0.34) between mountain goats and mountain sheep and consistently lower (P < 0.03) for these species than for pronghorn, mule deer, and wapiti. Differences in digestive efficiency among species were inversely related to dry matter intake rates. Apparent digestibility of dry matter, organic matter, and neutral-detergent fiber was 10-20% higher for mountain goats and mountain sheep than for the other species (P < 0.04). Although these findings suggest a superior digestive efficiency for mountain goats and mountain sheep, species comparisons are inconclusive because of the confounding effects of season and ambient temperature on voluntary intake and digestion. Under the conditions of this experiment, the diet tested was safe, nutritious, and highly palatable. Protein and energy concentrations appear to be sufficient to meet or exceed known nutritional requirements of captive wild ruminants.