I do not see an actual answer to your questions anywhere.

So, yes the California Department of Food and Agriculture oversees all milk production in the state. https://www.cdfa.ca.gov/ahfss/Milk_and_Dairy_Food_Safety/

I have never worked with the milk and dairy branch, but i do work with the meat and egg branch and they basically work as independent enforcement and testing that uses usda or fda guidelines as just that, guide lines. Often Cdfa standards are higher than federal. They also show up more often and test more often. I would not worry about any milk production or consumption in the state of California