Butter is a dairy product made by churning fresh cream which separated from Yak milk.It has unique and wonderful flavor,but also nutrient - rich;rich in vitamin A,vitamin D,vitamin E,cholesterol and various essential fatty acids.It can play the role of anticancer,cardiovascular disease prevention and enhance immunity. Butter is used as a spread and a condiment,as well as in cooking applications such as baking,sauce making,and frying.