Fatty-acid, amino-acid and mineral composition of two milk replacers for marsupials

Abstract

Although milk replacers are widely used to feed orphaned and injured marsupial joeys in Australia, little is known about the nutrient composition of these foods. We analysed two milk substitutes, Di-Vetelact (DiV) and Wombaroo Kangaroo (Wom) [milk stage >0·7 (joeys having completed 70% of their pouch life)], for their content of fatty acids, amino acids, and minerals and trace elements. The protein contents of DiV and Wom were 25·0% and 17·3% of fresh weight, respectively, and, except for tryptophan, the amino-acid profile compared favourably with three high-quality proteins. The fatty-acid content of DiV and Wom was 9·65% and 17·6%, respectively. Relative to marsupial milk, linoleic acid (DiV, 18·3%; Wom, 9·32%) and α-linolenic acid (DiV, 2·97%; Wom, 3·94%) were well represented in both milk replacers, but docosahexaenoic acid was not detected. Comparable amounts of zinc, iron, potassium, calcium, magnesium and phosphorus were present in DiV and Wom, but the copper content of DiV was only 5% that of Wom and manganese was not detected in DiV. These data indicate that two popular marsupial milk replacers contain healthful amounts of many essential nutrients relative to marsupial milk but lack the docosahexaenoic acid that is critical for brain growth and development in mammals. © 2013 The Zoological Society of London.