If the buyer and seller do not agree upon a sample of milk as provided in section 4.1-25-43, the party selling or offering for sale that milk may require that the buyer or prospective buyer to forward the sample taken to the department in compliance with section 4.1-25-27. Each sample so forwarded must include an affidavit from the buyer or prospective buyer, stating that the sample was taken in compliance with the provisions of section 4.1-25-27, and the statement must contain all information required in section 4.1-25-43, except that the signature of the seller is not required. Each sample must be tested and reported on as prescribed in section 4.1-25-43, and the percentage of butterfat determined and reported constitutes the “official butterfat test” and is the basis on which final settlement must be made.