Japan has eased some of its restrictions on U.S. beef, so exports to the Asian nation may grow. Since February 1, 2013, Japan is allowing U.S. beef shipments to come from cattle as old as 30 months, which is a widely used standard.

For several years, Japan has restricted beef imports only to animals 20 months or younger because of concerns about mad cow disease. Younger cattle are believed to pose less of a risk of carrying mad cow disease, but U.S. officials had criticized Japan's tough 20-month standard. Japan banned all U.S. beef imports from 2003 to 2006 after the first case of mad cow disease in America.

Before the ban, Japan was the largest buyer of U.S. beef, spending $1.3 billion in 2003. Since the ban, Japanese beef imports from the United States have not topped $1 billion in a year, although they were expected to in 2012. However, with the end of the ban, U.S. beef exports to Japan in 2013 are forecast to increase about 45 percent, reaching $1.5 billion.