Creekstone BSE Case: Latest Rulings And A “New Test” Development (Yankton Press & Dakotan) The discovery of bovine spongiform encephalopathy (BSE), often referred to as Mad Cow Disease, in the US cattle herd in December 2003 resulted in a precipitous drop in US beef exports. In order to reclaim its share of those export markets, Creekstone Farm Premium Beef decided in early 2004 to test each cow it slaughters for BSE. [News Source]