Gerald Nielsen, a prominent New York breeder instrumental in building up the state's breeding industry, has died. The cause of death was not immediately known, but Nielsen had been scheduled to come to Albany Monday to lobby state officials on breeding issues.Nielsen was unanimously re-elected last month to a second, two-year term as president of New York Thoroughbred Breeders Inc. He was owner of Sunnyfield Farm in Bedford, N.Y., and two years ago, with and wife, Joanne, were named Breeders of the Year in New York.The top horse bred by Nielsen was Capades. The New York-bred filly was a grade I winner and millionaire."He was just a great human being. He united the breeders. He had a good rapport with everyone in racing. He was very honorable and very honest,'' said Dennis Brida, executive director of the breeders group.Brida said Nielsen was to meet him in Albany for a round of meetings with legislators and aides Monday. The Nielsens bred the 2001 New York champion turf male, I'm All Yours, as well as stakes winners Roman Dancer and Along Came Mary."He's going to be sorely missed,'' Brida said.