If you don't mind sugar with your milk, milk is easy to stock pile. Just buy sweetened condensed milk. Its canned and not acidic so its about as bomb proof as a food can get.

Also, sweetened condensed milk is an all around good survival food. High in calories, about 1200 per a 14 ounce can. Its also dense in nutrition vitamins A and B, carbohydrates, protein and fat. Its also easier to digest then uncondensed milk.
_________________________
A gentleman should always be able to break his fast in the manner of a gentleman where so ever he may find himself.--Good Omens