The board is hereby vested with authority to confer with legally constituted authorities of other states and of the United States with respect to uniform milk control within the states and as between states. The board is authorized to join with such authorities of other states and with the authorities of the United States to conduct joint investigations, to exchange information, hold joint hearings and issue joint, complementary or concurrent orders, and to enter into a compact or compacts for such uniform milk control, subject to such Federal approval as may be authorized or required by law.