Fresh milk from the cow.
Not that I have tried it "straight" from the cow. but cooled whole fresh milk from the cow before it is taken from the farm is soo much better than standardised, homogenised, pasteurised milk bought at the supermarket..These three process are only present to improve the manufactures profit, presentation, and self life of milk in that order, and do nothing to improve the flavour. Heating it back upto 40 degrees or warmer makes for a pleasent drink.
Being bought up on a farm, drinking cows milk was the most natural thing you could do, however, I now would agree with others here, there is nothing "natural" about drinking cows milk, if you asked anybody to suck on a cows teat they would probably become nauseous at the idea, but they are doing just that, (Less the supply chain in between).
I see no reason why people cannot buy normal (Human) milk ice cream.