CHICAGO, March 9 (Reuters) - About 3,800 JBS meatpacking workers in Greeley, Colorado, plan to go on strike starting on March 16, the workers' union said on Monday, crippling production at one of the largest U.S. beef plants as consumers face record-high prices.

The labor disruption pits a workforce made up largely of immigrants against the world's largest meat company, and it has already driven ranchers to deliver cattle to alternate facilities.

Beef prices set records this year after the nation's cattle supply dropped to a 75-year low. Meatpackers including JBS benefit from climbing prices but also must pay record costs to buy cattle to slaughter.

JBS in November reported third-quarter profit of $581 million, down from $693 million a year earlier.

"While customers are paying more than they ever have, none of that is trickling down to the frontline worker that's actually doing all the heavy work," said Kim Cordova, president of the United Food and Commercial Workers Local 7 union that represents workers in Greeley.

JBS has participated in unfair labor practices and not negotiated fairly on a new contract over the past eight months, Cordova said. Workers sought wages that keep pace with inflation and wanted the company to stop charging them for replacing protective equipment they wear to do their jobs safely, she said.

JBS said it complies with labor laws, sought to reach a fair agreement, and charges employees for protective equipment that is lost or maliciously damaged.

"We stand by the offer we presented," JBS said. "It is strong, fair, and consistent with the historic national contract reached in 2025."

Last year, unionized meatpacking workers at multiple plants ratified a first-ever national contract with JBS. However, workers in Greeley already had some benefits in that contract, including sick leave, Cordova said.

JBS said it was now adjusting cattle deliveries and processing schedules at Greeley and shifting production to other facilities to meet customer needs.

The company did not slaughter cattle at the plant on Monday. Cattle feeders said JBS canceled slaughtering in Greeley for the whole week, and one feeder said he was delivering livestock to a company facility in Cactus, Texas, instead.

"We've got way more kill space than finished cattle ready to slaughter," said Corbitt Wall, a livestock market analyst for DVAuction. Ranchers will "just move them somewhere else."

Rival meatpacker Tyson Foods closed a massive beef plant in Nebraska this year.