I like to show Dirty Jobs - Dairy Cow (not the entire thing, just to cover the care of the cows on the carousel and getting the milk.
Then I go over the Milk Facts WS
You will need to find a document that tells you how to set up the milk tasting lab, super easy! I wish I could find mine to attach for you.
I do have a lactose lab alternative for the kids that won't taste milk.