Cal. Food & Agric. Code § 64221

Every handler and producer-handler shall keep complete and accurate records of all milk in unprocessed form that the handler or producer-handler purchases, or possession or control of which it acquires from any producer or other handler. Every handler that produces milk and producer-handler shall include its own production in these records. Every handler and producer-handler shall also keep complete and accurate records of all milk that it utilizes for processing.