Extensive testing in other countries where bovine spongiform encephalopathy (BSE) has been a major problem (United Kingdom, European Union, Japan, etc.) has indicated that younger animals, such as those typically harvested in the United States, do not test positive to BSE. Testing 100% of animals harvested would not provide a benefit. Testing of older animals and animals showing suspicious signs provides the best opportunity to detect any positive animals that might exist in the United States.