Japan’s Food Safety Commission has raised the age requirement for testing slaughter cattle for BSE from 21 months to 30, according to an article from the Japan Times. The commission now is considering raising the testing age to 48 months.

In February, Japan relaxed its restrictions on imports of U.S. beef, changing the age requirements from under 20 months to under 30 months, opening the market to a much larger share of U.S. beef.

After Japan found its first domestic case of BSE in 2001, the country began testing all cattle for the disease at slaughter. Since then, they have used animal age to determine whether to use the test, gradually focusing on older animals.