Miranda Lambert has canceled her Australian tour with Alan Jackson because of a respiratory infection, according to a message posted on her website. Lambert was scheduled to begin the tour on Friday (March 4) in Melbourne. Her opening act slot will be filled by Jasmine Rae, McAlister Kemp and John Williamson on various dates. "I was very much looking forward to Australia with Alan Jackson and performing for all the music lovers Down Under," Lambert said. Her next U.S. concert date is March 16 at the Houston Livestock Show and Rodeo.