In the event the required number of swine producers approve by a referendum as provided in this article the levying of an assessment upon the sale of swine for a promotional program, the Commissioner of Agriculture and Industries shall, within 30 days, notify in writing every person licensed to operate a livestock market under authority of Sections 2-15-60 through 2-15-71, other persons who conduct livestock sales and purchasing establishments, including the sale of feeder pigs, and every person who operates a meat packing or slaughter establishment which buys swine directly from the producer, that on or after the date designated in such notice, which shall be not less than 30 nor more than 60 days after the mailing of such notice by the Commissioner of Agriculture and Industries, the amount of the assessment shall be deducted by all such sales markets or purchasers of swine or by their agents or representatives from the purchase price paid to the seller of such swine where such swine are purchased within the state. On or before the tenth day of each calendar month, all assessments so deducted shall be remitted to the Commissioner of Agriculture and Industries less three percent thereof, which may be retained to compensate the stockyard operator, meat packer or other such establishment for the expense of collecting and remitting such assessment. The books and records of all such purchasers of swine shall at all times during regular business hours be open for inspection by the Commissioner of Agriculture and Industries or his duly authorized representatives or agents for the purpose of ascertaining the accuracy of the amounts remitted as required by this section. The Commissioner of Agriculture and Industries shall deduct from all sums remitted to him under this section, to defray the expense incident to collection and administration of this article, an amount to be set by the Board of Agriculture and Industries, but such amount shall not exceed three percent of such sum remitted. All amounts so deducted by the commissioner shall be paid into the State Treasury to the credit of the Agricultural Fund.