Idaho Code § 37-506
All milk and cream purchased or sold in the state of Idaho at a price based upon or determined by the milkfat, protein, lactose, solids nonfat or somatic cell counts thereof, shall be tested by methods approved by the director of the department of agriculture of the state of Idaho. Samples must be taken from every shipment of milk and cream. Accurate thermometers must be provided at all times. Milk and cream samples must be protected and in a tamper-proof place between thirty-three (33) and forty-five (45) degrees Fahrenheit. Such samples may be examined and tested by the department of agriculture at any time. The department of agriculture is authorized to conduct audits of a person's, corporation's, cooperative's or company's payments for milk or cream to determine if such payments comply with established requirements.
Idaho Code § 37-506