Mo. Rev. Stat. § 196.705: Fat or oil other than milk fat prohibited.

It shall be unlawful for any person, firm or corporation, by himself or itself, his or its agent or servant, or as the servant or as agent of another to manufacture, sell or exchange, or have in possession with the intent to sell or exchange, any milk, cream, emulsified cream, skim milk, buttermilk, condensed or evaporated milk, powdered milk, condensed skim milk, or any of the fluid derivatives thereof, or any of them, to which has been added any fat or oil other than milk fat, either under the name of said product or articles or the derivatives thereof, or under any fictitious or trade name whatsoever.