And each day at least one meatpacker at the plant gets hurt on the job.

On the killing room floor, beef carcasses dangling from an overhead conveyor belt constantly stream past blood-splattered workers - each with a very specific job to do.

A worker slits the throats of one cow as its blood rushes down to the pit below him. One man skins the animal. Another worker disembowels it. On the processing floor, hundreds more meatpackers working in near freezing temperatures carve the meat into the cuts that will land on grocery store shelves. And they do the same thing cow after cow until their eight-hour shift is done.

For years, the 3,100 workers who toil here have accepted injuries as a risk of working in one of the nation's most hazardous occupations. Now they are seizing upon those injuries to buck a trend of low union participation, which grew as the nation's meatpacking industry consolidated and drew more immigrant labor.

Ramon Sandoval, a 63-year-old Tyson worker, grimaced as he tried to make a fist with his swollen right hand. Nerve damage from the repetitive work cutting meat has injured it, and the company has since put him on light duty.

''We are fighting for justice, dignity and respect,'' he said.

Adopting farm labor organizer Cesar Chavez's rallying cry: ''Si, se puede!'' [''Yes, we can''], immigrant workers have now taken on behemoth Tyson. On March 1, workers will vote on whether to unionize under the United Steelworkers union. If they succeed, the union would represent 2,450 workers in Tyson's Holcomb plant, about 80 percent of whom are Latino.

The unionization vote is the second recent challenge these workers have mounted. In May, Holcomb workers sued Tyson, alleging the company violated labor laws by not paying them for time spent putting on and taking off protective equipment.

The workers face a formidable opponent. Tyson is the world's largest processor of chicken, beef and pork - employing 114,000 people at 300 plants around the globe. Human Rights Watch reports that about 30,000 employees in 33 Tyson facilities are represented by unions.

Union membership and wages in the nation's meatpacking industry plummeted in the 1980s amid plant closings and lengthy strikes, according to a study by the Agriculture Department's Economic Research Service. Union rolls remained stable through the 1970s, but fell from 46 percent of workers in 1980 to 21 percent in 1987, and have stayed at those lower levels.

Declining unionization coincided with changes in the slaughter plants' demographics, with immigrants from Southeast Asia, Mexico and Central America making up larger shares of the work force, the study found. The frequent movement of immigrant workers limited opportunities to organize unions.

The Holcomb workers hope bringing in the union will help slow the production line to limit repetitive strain injuries, while getting them better health insurance and retirement benefits.

Workers last year reported 452 job injuries at the plant. One man died in December after getting hit in the head by a large metal door, Occupational Safety and Health Administration (OSHA) logs show. While the reported injury rate at the Holcomb plant was higher than national averages, the company contended the number of serious injuries was far lower.

Nationwide, about 47,500 workers in the animal slaughter and processing industry were hurt in 2005 while on the job, a rate of 9.1 injuries per 100 workers, Bureau of Labor Statistics data show. That same year, 13 workers were killed.

The number of injuries has fallen by almost 70 percent since 1990, when the industry partnered with OSHA and the United Food and Commercial Workers union to develop ergonomic guidelines, said Janet Riley, spokeswoman for the American Meat Institute.

But government statistics mean little in the day-to-day life of worker Manuela Lujan. The 44-year-old Tyson employee said the vapors from chemicals used where she works are often so strong that her nose bleeds and her eyes water, and even at home she often cannot stop coughing.

Lujan added she is worried about a pregnant co-worker on another shift.

''She says she can't complain because she doesn't have legal work papers. What can we do? Nothing,'' said Lujan.

''Tyson feels they have a never ending supply of cheap, immigrant workers,'' said union organizer Mark Pitt. ''Nobody holds them accountable, and they don't care.''

Plant manager Paul Karkiainen dismissed the latest unionization issues as the ''same kind of rhetoric'' as a failed effort in 2000, when 78 percent voted against two other unions.

''It always makes it harder when you have someone trying to intervene between you and your employees,'' Karkiainen said as he proudly showed off one of the two medical dispensaries during a tour of the 1 million-square-foot slaughterhouse.

Karkiainen said the number of injuries at Holcomb seems high because the company encourages workers to report all injuries and it's one of Tyson's biggest plants. He contended that the rate of serious injuries is low, as seen by its lost time rate.

The plant has a safety committee, and every line has at least one safety committee member. Each worker is outfitted with $400 worth of protective equipment, Karkiainen said.

''Having a union doesn't guarantee you a good safety record,'' he said.

Tyson said it could not address the individual personnel matters cited by employees interviewed for this story since they are considered confidential. However, spokesman Gary Mickelson said Tyson routinely monitors carbon dioxide levels from the dry ice used in packing some meat products to comply with federal limits. The company abides by medical restrictions placed on workers by their physicians, he said, adding that Tyson encourages workers to go to their supervisor or other manager if they have any concerns.

Back at union offices in nearby Garden City, Ricardo Pinto hobbled in on a crutch. He broke his leg in a forklift accident at the plant in October and now works in the laundry until he heals. The 55-year-old immigrant from El Salvador has worked here for 13 years, and showed some old scars to prove it.

''We all think we are going to work here for a short time, but time absorbs us,'' he said.

Many immigrants are not concerned about pensions, health insurance or the future, Pitt said, because they plan to work here short term and return to their home countries.

Pitt says a lot of his work since arriving a year ago has been educating the immigrants on what a union does, and how they can stand up for themselves.

''It is harder because some of the workers are convinced this is sort of their lot in life here,'' Pitt said.

Breaking out the facts

* BY THE NUMBERS: Each day 150 semitrailers loaded with cattle arrive at Tyson Food Inc.'s Holcomb plant for slaughter. Each day workers here butcher 5,700 head of cattle. And each day at least one meatpacker at the plant gets hurt on the job.

* FIGHTING BACK: On March 1 workers will vote on whether to unionize under the United Steelworkers union. If they win, the union would represent 2,450 workers at the plant.

* BUCKING A TREND: In 1980, 46 percent of workers in the meat products industry were union members. By 1987, union membership in the industry had fallen to 21 percent, and has stayed at those lower levels.