WASHINGTON - The chief executive and founder of Creekstone Farms said Friday that even if Japan accepts U.S. beef, his company should still be allowed to test all its cattle for mad cow disease to help grow the Japanese market.

Testing for bovine spongiform encephalopathy "will help us instill confidence in our consumers," said John Stewart of Arkansas City-based Creekstone. "We still know that consumers there are skittish on U.S. beef."

Creekstone filed for summary judgment in its suit against the U.S. Agriculture Department in federal court Friday, arguing that the government has no right to keep the company from testing its cattle for mad cow disease.

The USDA has until Aug. 25 to respond to Creekstone's filing.

The USDA has kept Creekstone from testing, saying it controls testing and citing scientific evidence that Creekstone would test cattle too young to register a reliable result. Stewart said the science on testing is "too young, and it's unproven" to conclude that.

Mad cow continues to be a concern in the global beef industry. Canadian health officials confirmed Thursday that a seventh case of mad cow disease has been found in that country, in a 50-month-old dairy cow from Alberta.

Except for a brief re-opening this winter, Japan has been closed to U.S. beef since the disease was found in an American cow in December 2003.