The Argentine government has authorized the export of live cattle for slaughter, reversing a prohibition that had been in place for over five decades, after the country's beef exports last year reached their highest level in a century.Argentina, famed for its beef cuts and traditional asado barbecue, is a ranching and farming powerhouse and a major exporter of processed soybeans, corn and wheat.Sales from the country's agricultural sector to foreign markets provide the largest source of hard currency for central bank coffers…