(a) The following classes of persons, firms and corporations shall keep such records as willfully and correctly disclose all transactions involved in their business:

(1) Any persons, firms or corporations that engage for intrastate commerce in the business of slaughtering any cattle, sheep, swine, goats, horses, mules or other equines or poultry or preparing, freezing, packaging or labeling any carcasses or parts or products of carcasses of any such animals or birds for use as human food or animal food;

(2) Any persons, firms or corporations that engage in the business of buying or selling (as meat brokers, wholesalers or otherwise) or transporting in intrastate commerce, or storing in or for such commerce any carcasses, or parts or products of carcasses of any such animals or birds; and

(3) Any persons, firms or corporations that engage in business in or for intrastate commerce as renderers or engage in the business of buying, selling or transporting in such commerce any dead, dying, disabled or diseased cattle, sheep, swine, goats, horses, mules or other equines or poultry or parts of the carcasses of any such animals or birds that died otherwise than by slaughter.

(b) Any records required to be maintained by this section shall be maintained for such period of time as the commissioner may by regulation prescribe.

(c) All persons, firms and corporations subject to the requirement of this section shall, at all reasonable times, upon notice by a duly authorized representative of the commissioner, afford such representative and any duly authorized representative of the Secretary of Agriculture of the United States accompanied by such representative of the commissioner access to their places of business and opportunity to examine the facilities, inventory and records thereof, to copy all such records and to take reasonable samples of their inventory upon payment of the fair market value therefor.