Dealers shall furnish to the Commissioner of Agriculture such information as he deems necessary, from time to time, to effectuate the policy and provisions of this part or any order, ruling, regulation or direction issued thereunder; and such information shall be furnished upon such forms or reports as the commissioner prescribes. Dealers shall keep within the state such books, records and accounts of their operations as the commissioner deems necessary for correctly furnishing information required hereunder; and such data shall be preserved for not less than two years unless the commissioner otherwise provides. Such information, books, records and accounts may pertain to or include: (1) The quantities, butterfat test and sources of milk or milk products produced, received or purchased and contracts with respect thereto; (2) the quantities used, sold or otherwise disposed of, stating the butterfat test and outlets in the various classes, grades and products of milk; (3) the prices paid and charged for such milk and milk products; (4) the cost of handling or distributing milk and milk products, including transportation or hauling costs; (5) all other matters relevant thereto or otherwise necessary to effectuate the policy and provisions of this part or any order, ruling, regulation or direction promulgated thereunder.