Power ML, Maslanka MT. 2009. The milk repository at Smithsonian’s National Zoological Park. In Ward A, Treiber K, Schmidt D, Coslik A, Maslanka M, Eds. Proceedings of the Eighth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Tulsa, OK.
Lactation, the exocrine secretion of milk from mammary glands for the nourishment of young, is a defining characteristic of mammals. All female mammals produce milk, and milk is the first food of all neonatal mammals. The diversity of the mammalian radiation is reflected in the diversity of lactation strategies that have evolved. This in turn is reflected in differences in milk composition among mammals. Lactation is an ancient mammalian adaptation that predates live birth. The egg-laying monotremes lactate, though they do not have nipples.28_PowerMilkComp.pdf     121 KB