(1) Under authority delegated by the provisions of 81-23-104, MCA, the following transactions of business among licensees under the Milk Control Act and among licensees and the general public are declared to be unfair trade practices subject to enforcement sanctions provided by statute, to-wit:

(a) The payment of a lesser price than the applicable producer price established by the board pursuant to the act by any distributor to any producer for milk which is distributed to any person, including agencies of the federal, state or local government.

(2) This rule and the rescission herein of any previously existing rule shall not affect any act or thing done or begun, liability incurred, or any right accrued or established or any penalty incurred or any such prosecution or proceeding, civil or criminal, pending or instituted under or on account of any such previous rule herein rescinded in whole or in part, to enforce any right or penalty or to punish any offense under the authority of any such previously existing rule, at the time this rule takes effect, but as to all such acts, things, liabilities, rights, penalties, prosecutions or proceedings and any such previously existing rule shall remain in full force and effect.

(3) It is the intention of the board that if any provision of the rule, or the application of such provision to any person or circumstance shall be held invalid, the remainder of this rule, or the application of such provision to persons or circumstances other than those as to which it is held invalid, shall not be affected thereby.

(4) Nothing contained in this rule shall be construed as requiring or authorizing the violation of any order, rule or regulation lawfully issued by any federal office having proper jurisdiction.