Quote: "Don't Drink Your Milk"

In no mammalian species, except for humans (and the domestic cat), is milk consumption continued after the weaning period (the period of breast-feeding). Calves thrive on cow milk. Cow milk is for calves.

From the 1977 book "Don't Drink Your MilK" by Frank Oski, MD, Chairman of Pediatrics (1985-1996), Johns Hopkins University

via The Paleo Answer