According to a list posted on the U.S. Department of Agriculture Web site, Mexico has suspended meat imports from 30 processing plants in 14 states, including some of the nation''s largest, the Associated Press reports. Among the plants listed on the site is the Smithfield Packing plant in North Carolina, the world''s largest pork slaughterhouse; three plants operated by subsidiary John Morrell & Co; a Nebraska pork run by subsidiary Farmland Foods Inc.; a Pennsylvania beef plant run by its Moyer Packing Co. unit; six operations run by Tyson Foods Inc.; Cargill Inc.; Swift Foods Inc.; Seaboard Corporation; and 11 small private companies in Illinois, Indiana, Kansas, Kentucky, Missouri, Oklahoma and Utah. A USDA spokeswoman said in an e-mail that Mexico had discussions over the course of the last five business days with the agency regarding concerns about the general condition of meat products, sanitation issues and "possible pathogen findings." Published reports, however, raised the possibility the move could reflect Mexico''s objection to a recently-enacted law that requires meat products to bear country-of-origin labels. ConAgra Foods Inc., which formerly owned Butterball-brand turkey, sold the company in 2006 and is not affected. ConAgra is incorrectly named on the USDA Web site as one of the plant operators. Tyson spokesman Archie Schaffer III said the company had no prior warning from Mexico about the ban and only learned of it when shipments were turned aside at the border. The ban could greatly affect the Springdale, Ark.-based company, as high feed prices have already strained its profits. Mexico represents 23 percent of its $3.8 billion of international sales in 2008, according to company statistics. According to published reports, the suspensions may be in retaliation for the U.S. putting a country-of-origin labeling law into effect on Oct. 1 in response to concerns about the safety of imports. On Dec. 18, Mexico joined Canada in opposing the law, which involves fresh beef and pork, in a complaint to the World Trade Organization. Canada''s government filed its complaint Dec. 1, saying it was concerned the U.S. rules were discriminating against Canadian agricultural exporters. The complaints generate a 60-day consultation period between the governments, after which the WTO can step in with an investigative panel. The country-of-origin labeling law, mandates the separation of foreign cattle and pigs in U.S. feedlots and packing plants. Foreign animals are also required to have more documentation about where they come from and, in the case of cattle, must have tags that indicate they are free of mad cow disease. Canadian farm groups say a growing number of meat plants in the U.S. are refusing to accept Canadian cattle and hogs for processing since the law went into effect. To see the complete plant list: http://www.fsis.usda.gov/OFO/export/lmexico.htm.