Blizzard conditions in the Central United States shut down some Cargill and Tyson beef and pork processing plants in the region, company spokesmen told Reuters by email on Tuesday.
Tyson Foods Inc, one of the biggest U.S. meat processors, said three pork processing facilities and one beef plant were closed.
"Three of our six pork plants are not operating today due to weather-related road conditions and one other plant will operate only one shift of production," said Tyson Foods spokesman Gary Mickelson.
He said the affected pork plants are in Iowa and Nebraska.
Mickelson added that one of the company's beef processing facilities is not operating and two others are scheduled to run reduced hours. Those plants are in Nebraska and Kansas, he said.
Cargill Foods spokesman Mike Martin said its beef processing plant in Schuyler, Nebraska, was not running on Tuesday due to wintry weather, "with adverse road conditions impacting employee travel safety and livestock transportation."
Smithfield Foods Inc, the world's largest pork processor and hog producer, said it does not comment on daily activities.
Industry experts said other meat processors were likely affected by the storm, which could trim more than 40,000 hogs and roughly 25,000 cattle from the day's overall industry slaughter.
They said companies affected by weather disruptions are expected to make up the downtime later in the week by increasing shift hours or adding to Saturday's slaughter.
Winds of up to 50 mph whipped up as much as a foot of snow that fell in hardest-hit sections of Kansas, Nebraska and Iowa, said meteorologists.
The majority of hogs are raised indoors, so the weather impact would be more associated with the ability to move pigs to packing plants, said Iowa State University economist Lee Schulz.
Industry participants have known about the storm for several days and have planned accordingly, either by adjusting shifts or delivering pigs ahead of time, he said.
For cattle that are exposed to the elements in feedlots, cold, wet weather can create muddy conditions that can cause stress.
"Wind is as big an issue as snow," said Cassandra Fish, author of industry blog The Beef.
Feedyards will focus on ensuring that cattle are fed and trying to move snow to keep alleys in feedyards clear. Cattle will slowly put on pounds with more of their feed intake directed at keeping warm than gaining weight, she said.