More Chinese companies participated in the World Pork Expo held last week in Des Moines in the U.S. state of Iowa, Expo exhibitor Jim Long was quoted by a local report as saying.

With China being one of world's largest pork markets, a lot of international visitors from China also came to the expo, Long said.

Many products at the expo were claimed to be labor-saving, or innovative to prevent disease outbreaks, he said.

As U.S. unemployment is at historical lows, finding skilled labors has become a challenge for U.S. hog producers and packing plants. Labor-saving equipment tends to be popular, Long said.