Officials at Smithfield Foods and Tyson Foods will shut down the companies pork plants today citing low margins and tight hog supplies.
Reuters' news service reports that Smithfield's pork plants in Sioux City, Iowa, and Sioux Falls, S.D., as well as Tyson's Columbus Junction, Iowa, pork plant will close for the day. Combined, those plants account for about 10 percent of the daily U.S. hog slaughter. 

Tyson officials noted further that some of the company's other pork slaughter facilities will operate at reduced levels this week. According to Reuters Smithfield officials declined comment on its daily plant operations.

During the summer months, hog supplies tighten as part of a long-standing seasonal pattern. Adding to the challenges this year is continued slow demand. Producer and packer margins alike are feeling the pinch.