Any person engaged in any of the businesses covered by this article may obtain from the commissioner a grading service and/or inspection service of the products of his business and the commissioner is hereby authorized and directed to provide such service to any person applying for same. The commissioner is authorized to establish grades and quality of the carcasses, or the parts thereof, of cattle, sheep, goats, other ruminants, rabbits and poultry, but each such grade or quality shall meet the minimum standards for the like grade or quality as required by the United States Department of Agriculture. However, the commissioner may, in his discretion, establish a grade of lower quality or designation than is now recognized by the United States Department of Agriculture, but such grade and quality so established and designated shall be clearly marked and with such identification as to avoid any confusion with grades or qualities as designated by the U. S. Department of Agriculture. However, no grade or quality shall be established or designated which will permit the sale of any meat, meat-food products or poultry unfit for human consumption.