Composition of Preferred and Rejected Eucalyptus Browse Offered to Captive Koalas, Phascolarctos Cinereus (Marsupialia).

Abstract

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 following 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%; magnesium, 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 concentrations 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.