Whole milk has had cream taken out of it. A cow gives milk at 3.5 to 5% fat. Whole milk in the carton is 3.25%. The FDA standard for milk says you can pull fat off to hit that number, and that's how it's done. All the milk in the case comes off one machine. Raw milk goes into a centrifuge. Fat is lighter than water, so the cream spins to the middle and the skim spins to the wall. Two pipes come off the separator, one cream and one skim. Everything after that is a mix. Skim plus a little cream is 1%, a little more is 2%, and 3.25% is whole. Half and half is 10.5% and heavy cream is 36%. The plant sets the ratio and fills the carton. There is no such thing as a 2% cow. It's whole milk with some of the cream pulled off, in a different carton at a different price. The cream that came off goes to the churn and comes back as butter.