Some shifts were canceled at JBS meatpacking plants in Marshalltown and Ottumwa yesterday after a cyberattack on the company.

An updated post on the Facebook page for the JBS plant in Ottumwa said the company is “continuing to work through our IT issues” and no pigs will be slaughtered today in Ottumwa on the first or second shift. However, shifts for other tasks within the facility in Ottumwa are still on for today.

JBS is based in Brazil and is the world’s largest meat producer. All of its beef plants were shut down Tuesday by the cyber breach. JBS plants that process pork — like the two in Iowa — had some level of disruption, but weren’t completely idled.

Markets were rattled by the news as JBS plants process about 20% of the cattle and hogs slaughtered in the U.S. The White House said the ransomware attack likely came from a criminal organization based in Russia.