Pasteurization allowed a longer preservation of the product and even its exportation. A´rag (mongol name of koumis) was already a popular drink in Mongolia at Genkis Khan's period. Genkis cavalery comprised 20 000 horses. It's to notice that the mare, just like the woman is a mono-gastric, and doesn't ruminate, whereas goats, cows and sheeps are poly-gastrics. Mare's milk has the closest composition to human milk.