Pork exports and the passage of the Trans-Pacific Partnership (TPP) are critical for the economic future of U.S. pig raising, industry and government officials said last week at the World Pork Expo in Des Moines.

"Twenty percent of farmer income comes from exports," said Darci Vetter, chief agricultural negotiator in the Office of the U.S. Trade Representative. "If we don’t maintain or expand these trade opportunities, that affects your pocketbook."

According to a recent study from the American...