Creekstone Farms Premium Beef, LLC is a beef processing company located in Arkansas City, Kansas. The company was founded in 1995 by John and Carol Stewart. Originally a purebred Black Angus farm in Campbellsburg, Kentucky, Creekstone Farms entered the processing business in 2003 with the purchase of a 450,000-square-foot (42,000 m2) processing plant in Arkansas City, Kansas. The company began processing Creekstone Farms Premium Black Angus cattle in May 2003. In the spring of 2004, Creekstone Farms launched an additional line of Black Angus products - Creekstone Farms Natural Black Angus Beef. John Stewart retired from the company in October 2007. Creekstone Farms is currently owned by Sun Capital Partners, an investment firm. When Mr. Stewart retired, he retained ownership of the farm in Kentucky, which has since been sold and no longer is connected to the Creekstone Farms brand. The company reports[when?] that Japans ban on U.S. beef beginning in 2003 caused the company to lose a third of its sales, prompting the layoff of about 150 people. Creekstone Farms is known for its attempt to test all of its beef for bovine spongiform encephalopathy (BSE, or "mad cow disease"). At a cost of about half a million dollars, Creekstone built a testing lab, the first inside a U. S. meat packing plant, and hired the necessary personnel. In 2004, however, the U.S. Department of Agriculture, which controls the sale of testing kits, refused to sell Creekstone enough to test all of its cows.