Partly true....All mammalian infants depends on milk. But only the humans continue to consume some form of milk or it's products while they are adults.
It's said that about 60 percent of Asian and African descent stop producing lactase, as they mature. This is the enzyme required to digest milk.
OTOH the people of northern European descent, however, tend to retain the ability to produce this enzyme and drink milk throughout their life.
PS: I have visited real Masai Mara villages and they said they drink milk with the Cows Blood. They cut a vein and bleed just enough blood to mix with the milk.