Japanese experts have concluded that tests have failed to identify any danger to humans from young cows infected with mad cow disease, sources said Wednesday.
A team from the Health, Labor and Welfare Ministry injected 11 mice with brain fluid from two young infected cows in Japan and found that the mice had not developed the disease, known as bovine spongiform encephalopathy, or BSE, up to 927 days after the injection, they said.
The 21- and 23-month-old cows were identified as infected with BSE in 2003, leading the government to limit imports of U.S. beef to meat from cattle under 20 months old.
The test results, which indicate that humans may not be infected with the disease by eating meat from BSE-infected cows older than 20 months, could encourage the United States to renew its request for Japan to raise the age limit for imports to 30 months.