Composition of Preferred and Rejected Eucalyptus Browse Offered to Captive Koalas, Phascolarctos cinereus (Marsupialia)*
D. E. UllreyA, P. T. RobinsonB and P. A. WhetterA
A Department of Animal Science, Michigan State University, East Lansing, Michigan 48824, U.S.A.
B Jennings Center for Zoological Medicine, Zoological Society of San Diego, San Diego, California 92112. U.S.A.
Browse representing 1.5 m of terminal growth from 11 species of Eucalyptus shoots or mature tree limbs was divided into portions which were either consumed or rejected by captive koalas. The follow- ing nutrient concentrations (dry basis) were found in preferred browse: crude protein, 5.9-17.8%; ether extract, 5.5-19.2%; neutral detergent fibre, 16.8-37.5%; ash, 3.2-5.6%; remaining proximate fraction [(dry matter) - (crude protein + ether extract + neutral detergent fibre + ash)], 31.7-64.8%; calcium, 0.28-1.95%; phosphorus, 0.08-0.42%; sodium, 0.03-1.29%; potassium, 0.30-2.06%; mag- nesium, 0.12-0.44%; iron, 67-274 ppm; copper, 2.1-15.8 ppm; zinc, 17-54 ppm; and selenium, 0.03-0.42 ppm. Preferred browse, as compared to rejected browse, had significantly higher concen- trations of crude protein, remaining proximate fraction, phosphorus and potassium, and significantly lower concentrations of ether extract, neutral detergent fibre, acid detergent fibre, permanganate lignin, gross energy, calcium, iron and selenium.