>Actually, I meant that primitive peoples might have consumed whatever
>milk was in the animal when it was killed.

You would be talking about an amount of milk about the equivalent to the
amount of raw grass seeds that would be eaten--i.e. a pittance.  Find a
lactating animal (how often are those available?  A few months a year, in
maybe a quarter of the prety population?), kill it, and extract and consume
whatever milk was in the udders (no more than a quart or two even for a big
animal, modern dairy cows are specialty bred pituitary freaks), and then
what?  Drink it yourself as the hunter, or share with your family so
everyone gets a tablespoon or two?

Dairy is as good as nonexistant to hunter/gatherers.  Whether it's a health
concern or not is the subject of considerable debate but it's certainly not
a "natural" food to the human animal.