Japan eased its limits on U.S. beef imports Friday with retailers now allowed to sell meat from cattle less than 30 months old.

All U.S. beef was banned following a case of mad cow disease in the American herd in 2003. The ban was lifted in 2005, but only meat from cattle less than 20 months of age was allowed.

Friday’s move was approved by Japan’s Food Safety Commission in October.

The commission said the difference in risk between beef from 20-month-old and 30-month-old cattle is “extremely small” and the effect on health when consumed can be disregarded.

The change means that about 90 percent of U.S.-produced beef will qualify for export to Japan, as exports generally involve cattle aged between 16 and 22 months, according to the Agriculture, Forestry and Fisheries Ministry.

U.S. Ambassador John Roos praised the move, saying, “this market expansion by Japan is a beneficial step for Japanese consumers, restaurants and retailers who will be able to enjoy a more diverse selection of safe, delicious and high-quality U.S. beef.”

“It will be around March that beef imported from the U.S. under the new rules will reach our customers,” a spokeswoman for Seiyu Group, which operates one of the country’s largest supermarket chains, told The Japan Times.

But already welcoming the rule change, the chain began slashing the price of U.S. beef Thursday by about 20 percent.

Seiyu expects to double annual sales of U.S. beef in 2013, and will possibly provide it at about 25 percent less than the current price, according to a press release.

“We intend to continue providing (U.S. beef) at a low price,” the spokeswoman said.

Before the outbreak of bovine spongiform encephalopathy (BSE), the U.S. exported 200,000 to 300,000 tons of beef to Japan annually. Recovery since the complete ban was lifted has been stable but slow, with imports reaching only 124,000 tons in 2011.

According to statistics from the Agriculture and Livestock Industries Corp., Japan imported more than 516,000 tons of beef in 2011, the highest amount since 2003.

The U.S. and Australia combined for approximately 90 percent of the total.

A report by the Food Safety Commission states that while there were more than 37,000 cases of BSE confirmed across the globe in 1992, the number dropped to 29 reported cases in 2011.

The commission said the drop was a result of appropriately managing livestock feed and implementing preventive measures.

In addition to beef from the U.S., Japan also eased the rules for Canada, France and Holland.

Information from Kyodo added