They don't get paid very much. It seems that the slaughterhouse operators care for people about as much as they care about animals.
Meat processing facilities are known to pose significant threats to worker safety. In 1996, meat packing workers were listed as having the highest rate of repeat-trauma disorders (like carpal tunnel syndrome, which develops over long periods of time)17. In 1998, nearly 30% of US meat packing plant workers sustained a work-related injury or illness, making meat packing the most dangerous job in the country in terms of non-fatal injuries18. Data from the Bureau of Labor Statistics shows (from 2003-2007) the rate of illnesses and injuries for workers in "animal slaughtering and processing" was over twice as high as the national average, and the rate of illnesses alone was over ten times the national average19. Common ailments among slaughterhouse workers include back problems, torn muscles and pinched nerves, as well as more dramatic injuries such as broken bones, deep cuts and amputated fingers and limbs20.
Although meat processing is a difficult and dangerous occupation, precautions can be taken to minimize the threats to worker safety. Among the most important safeguards is to set reasonably-paced production line speeds so that workers are able to process meat without putting themselves or their coworkers at risk of injury. However, in order to maximize profits, meat processing companies continue to maintain unreasonably fast line speeds, thereby jeopardizing the safety of both workers and the food supply.