yogurt or cream cheese would both work, as well.

the origins of various foods is facinating... a wonderful film called The Weeping Camel shows a bit how the pastoral folks of Mongolia live by milking their flocks and consuming the milk flavored with various herbs. Sheep, goats, horses and camels are all milked... yaks, cows and water buffalo are milked elsewhere in the world.   Butter is rendered down into ghee - clarified butter- to preserve it and meat is a rarity in the diet. Only so many excess bucks & rams to be found in a culture that measures wealth in livestock.