The grading service herein provided shall be conducted by the Department of Agriculture at a cost to be established by the Department and the proceeds shall be used for the purpose of paying salaries, travel and related expenses of grading personnel. These proceeds shall be deposited with the State Treasurer to the account of the Department to be expended for the purposes authorized in this chapter. The grading shall be conducted only by personnel who are certified by the Department and who have successfully completed tests and examinations to determine proficiency in grade application which are administered by the Livestock Division, Consumer and Marketing Service, United States Department of Agriculture. Grading personnel are responsible only for placing animals for sale into the proper grade categories as determined by standards promulgated by the Department.