UPDATE 1-U.S. weekly beef exports to Japan hit two-year high

* Sales hike comes after Japan relaxes import rules * Rules were put in place after US mad cow disease By Theopolis Waters CHICAGO, Feb 22 (Reuters) - U.S. beef export sales to Japan soared to their highest in more than two years last week following Tokyo's decision to ease import rules related to the outbreak of mad cow disease in 2003, government data showed on Friday. Japan, once the top market for U.S. beef, on Feb 1 began allowing U.S. beef imports from cattle up to 30 m