Section 117D. The commissioner may employ inspectors to inspect such farm products marked, branded or labelled in accordance with official grades or standards established and promulgated by the commissioner, for the purpose of determining and certifying the quality and condition thereof and other material facts relative thereto. Certificates issued in pursuance of such inspection and executed by the inspector shall state the date and place of inspection, the grade, standard, condition, and approximate quality of the farm products inspected and any other pertinent facts that the commissioner may require. Such a certificate and all federal certificates relative to the condition or quality of said farm products shall be prima facie evidence in all courts of the commonwealth of the facts required as aforesaid to be stated therein.