"When one cow was found with BSE in 2003, many of our trading partners closed their borders to our beef"

This quote by Mike Johanns is describing the 2003 discovery of a cow in the United States with Bovine Spongiform Encephalopathy (BSE), typically called mad cow disease. This discovery triggered a lot of concern amongst the United States' trading partners, as BSE is a serious and potentially deadly disease. As a result, a number of the United States' trading partners closed their borders to American beef, in order to secure their own people from the potential danger of BSE. This had a substantial impact on the American beef industry, as it was unexpectedly cut off from much of its significant markets. The discovery of BSE in 2003 was a major setback for the American beef industry, and it took years for the market to recover from the resulting financial losses.