No clearance shall be given to any vessel having on board any fresh, salted, canned, corned, or packed beef, mutton, pork, goat or equine meat for export to and sale in a foreign country from any port in the United States, until the owner or shipper thereof shall obtain from an inspector appointed under the provisions of this chapter a certificate that the said amenable species were sound and healthy at the time of inspection, and that their meat is sound and wholesome, unless the Secretary shall have waived the requirements of such certificate for the country to which said amenable species or meats are to be exported.