4/24/2012 1:20 PM

On April 24, the USDA announced the nation's fourth case of bovine spongiform encephalopathy (BSE), sometimes called mad cow disease, in a dairy cow from central California. Dr. John Clifford, USDA's chief veterinary officer, answers a series of questions about this BSE case.

Can American expertise significantly boost the productivity of third-world farmers?

  • Yes
  • No
  • Unsure

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3/29/2015 | Last Updated: 7:15 PM