e-Moo, the dairy-based carbonated beverage for children developed by Delaware-based Mac Farms, has received the USDA's seal of approval as the only carbonated nutritional beverage allowed to be sold in public school cafeterias. Since 1991, the USDA has not allowed flavoured, sweetened, carbonated products to be sold in school cafeterias. The US school food service market, grades K-12, is comprised of approximately 6,200 schools.