just got this from macdonalds website
McDonald's has two types of milkshake machines. One pasteurises the milk every night and is taken apart and cleaned once a week. The other one is disassembled and sanitised every night. The milk can be topped up, but is completely discarded every week. This way, McDonald's can ensure its' milkshakes are always safe to drink.
so atleast we no there pasteurised!!! as ive been drinking them didnt even enter my head not to, have done in all my pregnancies.