KANSAS CITY, MO. — Both Smithfield Foods and Tyson Foods officials said their companies have shut down their pork plants on July 13 for the entire day because of low margins and tight hog supplies, according to Reuters news service. Those plants combined account for about 10% of the daily U.S. hog slaughter.

Smithfield's pork plants in Sioux City, Iowa, and Sioux Falls, S.D., and Tyson's Columbus Junction, Iowa, pork plant will not operate for the day. Tyson officials added some of the company's other pork slaughtering facilities will operate at reduced levels this week.

Hog supplies during the summer months usually tighten. Continuing slow demand is adding to industry’s challenges this year. As a result, both producer and packer margins are being negatively impacted.