The commissioner is hereby authorized to confer with legally constituted authorities of other states and of the United States with respect to uniform milk control, including sanitary requirements with states and/or as between states, and with the federal government in its control of milk handled in interstate commerce, and may exercise his powers hereunder to effect such uniform milk control. He may join with such other authorities federal and state in conducting joint investigations, holding joint hearings and issue joint or concurrent orders, or orders supplementary to those of the federal government, and shall have the power to employ or designate a joint agent or joint agencies to carry out and enforce such joint, concurrent or supplementary orders. In order to carry out the policies set forth in sections two hundred fifty-eight-k and two hundred fifty-eight-p, the commissioner is hereby vested with the authority to enter into a compact or compacts or other types of agreements, with the legally constituted authorities of other states and/or the United States to provide for uniform milk control and, in order to effectuate such uniform milk control, he may join with an agent or agencies to exercise under such compact or compacts or other types of agreements the powers conferred upon him by this article with respect to the administration of uniform milk control. In the case of market orders including those covering prices, any such compact or compacts or other types of agreements may provide for necessary assessments upon the handlers regulated thereunder, in order to cover the cost of administering such uniform milk control, including, without limitation, the cost of auditing milk dealers’ classifications. The commissioner may effectuate this section by any type of agreement other than a formal compact if a formal compact is not constitutionally required.