Milk composition of the Tasmanian pademelon (Thylogale billardierii Desmarest) (Macropodoidea : Marsupialia) in captivity

Abstract

This is the first study of milk composition in any member of the wallaby genus Thylogale. Milk samples (n = 44) were collected after oxytocin injection from 12 females carrying pouch young aged 2–30 weeks followed by sampling of the mothers until weaning by Week 39. The lactation period could be partitioned into early (Weeks 2–20), mid (Weeks 21–30) and late (>30 weeks) stages. Although milk concentrations changed little during lactation the energy content increased almost 4-fold from 540 ± 39 kJ (100 mL)^–1 (mean ± s.e.) to 1908 ± 102 kJ (100 mL)^–1. Carbohydrate concentrations decreased from 13.3 ± 0.1 g (100 mL)^–1 (early lactation) to 10.9 ± 0.9 g (100 mL)^–1 in mid-lactation, falling to 4.8 ± 0.9 g (100 mL)^–1 in late lactation. Lipid increased from 6.3 ± 1.1 g (100 mL)^–1 to 12.5 ± 4.1 g (100 mL)^–1, reaching 31.4 ± 5.0 g (100 mL)^–1 in late lactation. Protein increased from 3.3 ± 0.1 g (100 mL)^–1 to 9.7 ± 1.6 g (100 mL)^–1 in mid-lactation to 14.0 ± 1.5 g (100 mL)^–1 in late lactation. This relatively high level of lipid and protein in late lactation may be the cause of the more rapid growth and, hence, shorter pouch life of the Tasmanian pademelon (Thylogale billardierii) compared with the well studied tammar wallaby (Macropus eugenii).