It's a cattle drive of historic proportions. For the first time in 40 years, animals from the U-S have been exported to Cuba. A shipment of one hundred forty cattle and bison from Minnesota and other midwestern states arrived in Cuba yesterday. Agricultural sales are allowed as an exception to the U-S trade embargo against Cuba. Ralph Kaehler , a farmer from St. Charles, coordinated the shipment. Kaehler said the Cuban buyers got more than they bargained for.