NOUAKCHOTT, Mauritania - Herd boys tug at camels' udders, loosing the raw material for a unique, creamy cheese this desert nation's growers hope to place alongside Roquefort and cheddar on the world's crackers. If foreigners bite, camel cheese exports could put sorely needed cash in the robes of this West African nation's nomads, helping them to modernize herding practices. But there are hurdles: European Union and American import and health regulations demand costly testing impoverished Mauritania, like most African nations, is unable to provide. "If the Europeans buy that cheese, our milk production will skyrocket. We'll get the technology —...