Wichita ? Kansas Agriculture Secretary Adrian Polansky said Tuesday the United States should weigh the full economic impact of mad cow disease against the costs of starting to test all cattle for the illness, which could speed resumption of international trade in American beef.

Last week, the U.S. Department of Agriculture rejected a request from Creekstone Farms Premium Beef for a certification allowing it to test every animal for mad cow disease at its Arkansas City plant.

Creekstone officials planned to notify the USDA late Tuesday they were considering legal action. In a memo obtained by The Associated Press, the officials urged the USDA to reverse its decision.

“BSE testing of our cattle is something our export customers and consumers are asking for, and we feel we should be able to provide it to them,” the officials wrote.

Japan — once this country’s leading beef buyer — has banned American beef since the first U.S. case of mad cow, known as bovine spongiform encephalopathy, was discovered in December. Creekstone has said its Japanese customers have assured the company they would buy its beef if it was BSE tested.

Polansky said he understood Creekstone Farms’ point of view.

“Testing every animal adds value to their product, and they should be able to employ whatever marketing strategy is appropriate for them,” Polansky said. “That’s a basic tenet of a free-market system.”

But Polansky said he also appreciated the Agriculture Department’s position against 100 percent testing.

“They have taken several measures that are appropriate to protect consumers, and there should be a sense of unity when addressing the concerns of our trading partners,” Polansky said.

Polansky said he would like to know the full economic effect of the disease — including costs to livestock producers and meat processors as well as the expanded BSE surveillance program planned by the Agriculture Department.

He said such an economic analysis would show how those losses compare to the cost of testing all animals, which could result in a more rapid resumption of trade.

About 50 countries imposed trade bans on U.S. beef after the discovery of mad cow disease. Mexico last week further eased trade restrictions, but most others have kept their bans in place.

Meanwhile, the Kansas Livestock Assn. has backed off from taking an official stance on private mad cow testing.

“We sure support Creekstone and want them to stay in business because it is another option for our members to market cattle to,” said Matt Teagarden, director of industry relations for the association. “But we do have some concerns about the far-reaching industry impacts private testing could lead to.”

Teagarden said cattlemen fear the costs of testing all the nation’s animals might eventually be passed to producers. That could take as much as $20 a head off the value of calves.

“We have discussed the issue, but we have not worked either way,” Teagarden said. “We have not gone to Washington and gone up and down the halls pushing for Creekstone’s decision. But we have not done the opposite pushing for USDA to deny their request either.”

Creekstone said in its memo to USDA that its revenue losses were at least $200,000 per day.

“We will continue to track this loss on a daily basis to determine damages,” the memo said.