More than 700 dairy farmers and others are expected to attend a two-day conference at Monona Terrace Convention Center in Madison next month.  The Green Bay-based Dairy Business Association is sponsoring the event.  The issues on the table for discussion range from immigration policy reform, to foreign trade, the environment, animal welfare and the changing market.  Access to foreign markets and farm and milk prices are expected to be the main topics.  The number of dairy farms has been dropping for years.  Ten years ago there were more than 14-thousand — today there are about 92 hundred.