TOKYO, April 3 (Kyodo) — A governmental food safety panel approved on Wednesday a plan to raise the age limit for exempting domestic cattle from testing for mad cow disease until they reach 48 months, up from the current 30 months.

The expert panel of the Food Safety Commission under the Cabinet Office concluded that the higher age limit for tests for the disease, formally known as bovine spongiform encephalopathy, would not have negative health effects.

The approval came after the exemption threshold for testing domestic cattle for mad cow disease was raised Monday from 21 months to up to 30 months.

The panel will formally suggest the new inspection threshold to the Health, Labor and Welfare Ministry after public consultations. The ministry will then start revising a related ministerial ordinance to reflect the change.

The first case of mad cow disease in Japan was reported in 2001. Japan began blanket testing of domestic cattle from October that year but eased requirements in August 2005, testing only cattle aged 21 months or older.

So far, 36 cows have been found infected with BSE in Japan, with the last animal testing positive in 2009.

Japan banned imports of U.S. beef in 2003, when the first U.S. case of mad cow disease was confirmed. It lifted the ban in December 2005 while imposing conditions including the requirement that the beef must come from cattle aged under 21 months.

Tokyo has since relaxed import restrictions on beef from the United States and Canada. In February this year, it raised the age threshold for imports, permitting the import of beef from cattle aged up to 30 months old, up from 20 months.