Abilities to digest dry matter, crude protein, and gross energy were evaluated for 2 captive grizzly bears (Ursus arctos) in 1977 and 1978. Four diets were used: 1 basal (horsemeat plus dog chow), 2 incorporating natural foodstuffs (blueberries and salmon), and 1 containing high fiber (beet pulp). Average apparent digestibilities (% dry weight) for the horsemeat plus dog chow, blueberry, and salmon diets were 82% (dry matter), 90.2% (crude protein), and 88.1% (gross energy). Relative digestibilities of specific foodstuffs in descending order were: blueberries, salmon, and beet pulp. Addition of beet pulp to the diet reduced measured digestibilities to: 48.7% (dry matter), 75.1% (crude protein), and 62.0% (gross energy). Grizzly bears feeding on horsemeat exhibited digestibilities similar to those reported for obligate carnivores. Although U. arctos has evolved omnivorous food habits and morphological adaptations for herbivory, it digests cellulose poorly but has apparently conserved the ability to digest meat efficiently. The ability to digest high quality forage rapidly is presumably a necessary concomitant of denning.
- Volume 5
- Issue
- Pages 179-185
- Publication Date 1 January 1983
- DOI 10.2307/3872536
- File Size 257.63 KB
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