DES MOINES, Iowa – On Capitol Hill, a $1.7 million earmark for pig odor research in Iowa has become a big, fat joke among Republicans, a Grade A example of pork. But the people who live cheek by jowl with hog farms in the No. 1 pig-producing state aren't laughing. They're gagging. "You hold your breath and when it's really bad you get the taste in your mouth," said Carroll Harless, a 70-year-old retired corn-and-soybean farmer from Iowa Falls. In Iowa, where the 20 million hogs easily outnumber the 3 million people, the rotten-egg-and-ammonia smell of hog waste often wafts...