Google it up. It’s a complex formula that artificially inflates the price of dairy products nationwide. Sugar has a similar scheme at the federal level.
I’m aware of the old milk price support program that was repealed and the Dairy Product Price Support Program that was also repealed by the 2014 farm bill and then replaced with ths dairy margin program which amounts to an insurance program that dairy farmers pay into to protect themselves against low margins. The old traditional dairy price supports no longer exist after the 1014 farm bill AFAIK.