Thousands walk off the job at JBS in Greeley on Monday morning

Thousands of union workers walked off the job early Monday at a major meatpacking plant in northern Colorado.

Roughly 3,800 employees at the JBS USA beef processing facility in Greeley began picketing before sunrise, calling for higher wages and safer working conditions.

The workers are represented by United Food and Commercial Workers Local 7. Union president Kim Cordova says the company has increased the plant’s production line speed to about 420 animals per hour, up from 390, putting additional strain on employees.

Union leaders say workers are also asking for reimbursement for protective gear that can cost hundreds of dollars each year.

The union has filed several complaints with the National Labor Relations Board, alleging retaliation and changes to working conditions by the company.

A spokesperson for JBS, Nikki Richardson, says the company has spent the past eight months negotiating with the union over a new contract and described its latest proposal as strong and fair.

Union leaders say the company offered a 60-cent hourly raise in the first year, followed by 30-cent increases in each of the next two years — but argue that the offer doesn’t account for Colorado’s higher cost of living.

The strike follows months of negotiations after the workers’ previous contract expired in July.

The Greeley facility is one of the nation’s largest beef processing plants, turning cattle into meat products that are shipped to grocery stores and restaurants across the country.