The department of agriculture shall fix, assess, and collect fees for certification or audit services provided by temporary inspectors employed under this part. The fees shall be in amounts necessary to cover all costs of the administration and provision of the certification or audit services provided under this part; provided that the department of agriculture shall establish charges for traveling expenses and extraordinary services when the performance of the services involves unusual cost. The fees and charges established by the department of agriculture shall not be subject to chapter 91. The department of agriculture may employ temporary inspectors to assist in providing certification or audit services under parts I, III, IV, VIII, and IX, and those temporary inspectors shall be exempt from chapter 76.