MADISON, Wis. (WRN) - Wisconsin Senator Herb Kohl has announced that he will retire at the end of his current term.  The 76 year old Democrat was first elected to the U-S Senate in 1988.  Besides being a Senator, Kohl also owns the Milwaukee Bucks NBA franchise and his family founded the Kohls grocery and department stores.  His current term ends in January of 2013.