Earlier this year, the Humane Society of the United States prepared a young animal rights advocate for the sorts of abuse they expected her to encounter when she went to work at a Wyoming pig farm last month. Even so, the activist -- and the Humane Society -- say they were appalled by the level of depravity they ultimately documented in an undercover video that has since touched off an investigation by state officials and raised fresh questions about animal welfare on the nation's factory farms.

"When you walk in, all of these sows are showing this volume of insanity," the undercover filmmaker, who requested anonymity out of concern for her safety, said in an exclusive interview with The Huffington Post. "They're swaying, they're biting the bars, they're listing in front of the cages and they're docked and bloody."

The abuse depicted in the video is unequivocal, and local law enforcement, as well as state livestock officials, have launched a probe of the facility, Wyoming Premium Farms, which is owned by the Japanese meat processing giant Itoham. Industry representatives have condemned the actions depicted in the video but have argued that they are aberrations in an otherwise amply regulated and humane system that produces more than 92 million pounds of meat and poultry in the U.S. annually. According to a USDA report released in April 2012, U.S. commercial hog slaughter in 2011 totaled 110.9 million head.

Doug DeRouchey, the manager of the Wyoming Premium facility, told The Huffington Post on Friday that his company was conducting its own investigation and that at least five employees have been fired. "We're reviewing all the options right now that are available out there," DeRouchey said. "There's probably going to be changes -- we don't know what."

Pork industry representatives told The Huffington Post that the abuse shown in the video is extraordinarily rare. "It's just like having a driver's license," said Paul Sundberg, vice president of science and technology for the National Pork Board, which promotes the pork industry. "Just because somebody runs a red light, doesn't mean there's a problem with red lights."

But animal rights advocates and other critics of the industry argue that red lights are being run far too often. They say the patchwork of state and local laws governing animal treatment at factory farms is demonstrably inadequate, and that a proliferation of similar animal-abuse videos suggest that the industry is incapable of policing itself. They also argue that what rules do exist are written so loosely that the industry is able to define, more or less for themselves, what's cruel and what's not.

"Things you would be thrown in jail for doing to a dog or cat, you can do with impunity to farm animals," said Paul Shapiro, the Humane Society's vice president for farm animal protection. "Not because pigs don't suffer like dogs do, but just because the agriculture business industry has been so politically influential, it's carved out these giant loopholes to evade responsibility for complying with the basic anti-cruelty codes we have in all states."

DOCUMENTING ABUSE

According to the Humane Society, an anonymous tip led the organization to focus its attention on Wyoming Premium, a collection of four facilities just north of the town of Wheatland. The farm, which provides jobs for as many as 60 people earning between $9 and $13 an hour, according to DeRouchey, is a major employer in the area.

The facility opened in 1995 and has occasionally tussled with local landowners over issues of odor and other complaints, but incidents of abuse have been rare, DeRouchey said.

"The first thing you'd notice is the smell of the barn," said the undercover Humane Society activist, who was hired in April to work in the pig breeding part of the operation. HuffPost requested that the activist provide a paystub to verify that she had worked for Wyoming Premium. "You can smell it from the street," she said of the facility. "People who were excited to have somebody new would tell me things like, 'You're going to see some fucked-up shit.'”

Over the course of a month, and equipped with undercover cameras, the activist documented male and female workers who appear to prod, punch and sit on a pig unable to move due to a broken leg. They can be seen flipping young piglets through the air, and sows can be seen squealing in restrictive "gestation stalls."

In one instance not captured on video, the Human Society said, a worker allegedly stuck an arm into a sow's anus, rather than into its uterus, causing a severe injury that went untreated for over a week.

The activist says she befriended a fellow worker -- a woman around her own age -- who expressed concern about the abuse. "I watched her apologize to some of the sows. She'd let them out during weaning. She'd walk around and treat abscesses on her own without being told to, and she was the only one that would," the activist said.

Where she could, the filmmaker says she intervened -- giving water to a dying sow and reporting the pig with the broken leg to a barn manager -- but the majority of the abuse captured in the video is perhaps most remarkable for its offhanded administration.

"They would just kick a sow in the face to get her to turn around, and the sow would scream and run away," the activist told HuffPost, "and I would just stand there and act like it was normal. And they think it is normal, because they’ve just been doing it for so long," she said, "or because that’s just how everybody else does it, or just because that's the easiest way."

ANOMALY OR STANDARD PRACTICE?

The National Pork Board's "Pork Quality Assurance Plus" program is designed to educate producers on food safety and animal care, and to provide guidelines and best practices for the industry.

Among other things, the PQA Plus manual describes abuse and neglect as:

[A]cts outside of normally accepted production practices that intentionally cause pain and suffering including, but not limited to: 1) Intentionally applying prods to sensitive parts of the animal such as the eyes, ears, nose or rectum; 2) Malicious hitting/beating of an animal; 3) Purposeful failure to provide minimal food, water and care that results in significant harm or death to animals.

If the abuse is observed, the guide suggests intervening and alerting authorities.

But according to the Humane Society's Paul Shapiro, acute violence like that seen in the Wyoming Premium video is hardly unprecedented. Precise numbers to back that up are difficult to compile, though Shapiro noted that while animal rights groups only conduct an estimated five to 10 investigations each year, abuse is discovered with "troubling frequency." He ticked off several recent cases of abuse uncovered at farms and plants from Vermont to California.

Indeed, the rise of video documentation of farm animal abuse prompted the Center for Food Integrity, a nonprofit formed in 2007 that represents farmers and ranchers, universities, food processors, restaurants and other members of the food supply chain, to form an Animal Care Review Panel in February.

Candace Croney, an associate professor of animal behavior and well-being at Purdue University and a member of the panel, said she believed the sort of rough handling seen in the Wyoming Premium Farms video was rare, though she added: "I can't tell you this is one isolated incident, based on the fact that these videos seem to keep recurring."

The only other video the panel has so far reviewed was taken at a pig breeding factory farm in Leland, Iowa. It showed what appeared to be the violent castration of squealing piglets, and adult sows squeezed into narrow gestation stalls -- controversial pens that prevent the pigs from turning around or even lying down properly, and in which they spend much of their adult lives. Such practices, however, are not considered extraordinary.

"As contentious as it may be, it's pretty much standard industry practice in the swine industry today," Croney explained. "The handling that you saw of those animals, while it may not be warm and fuzzy, was not abusive handling of animals."

Dave Warner, a spokesman for the National Pork Producers Council, an industry group, said gestation crates help to protect pigs from weather extremes and diseases, while allowing for individualized attention to health. "The only real measure we have of whether they're doing well in that type of system is the number of piglets they're having, and that's at an all-time high."

DeRouchey said pigs are happier in the pens. "There's a lot of noise going on because it's feeding time," he said, referring to the pigs in gestation crates seen in the video. "Most people don't realize that's what's going on. They're all happy at the gestation stall environment: they all get fed at the same time."

Still, restaurant and grocery chains like McDonald's, Safeway and Smithfield Foods have all begun to distance themselves from factory farms that use gestation crates. In Europe, Great Britain and Sweden have banned the practice. Denmark will phase out their use next year, and several U.S. states have outlawed the crates, including California, Arizona and Florida.

More generally, oversight of animal welfare on factory farms in the U.S. is spotty. The federal Animal Welfare Act regulates the treatment of animals in research, exhibition, transportation and by dealers, but it does not extend to the treatment of farm animals. Dave Sacks, a spokesman for the U.S. Department of Agriculture, said such AWA oversight "would take Congress stepping in."

There are federal laws that apply to the slaughter and transportation of farm animals, but Shapiro argued that these are inadequate and that better laws are needed to protect animals while they are being raised. "The amount of time animals spend in a federally inspected slaughterhouse is minutes," he said. "On farms it's years. For 99 percent of their lives, they have no federal protection."

Virtually all states have animal cruelty provisions, but they often exempt what critics say are ill-defined industry standards. According to state Sen. Fred Emerich (R-Cheyenne), Wyoming passed new livestock legislation, effective July 1 of last year, "because of considerable ambiguity over who had jurisdiction." The legislation also clarifies that it is illegal to commit an "act, omission or neglect whereby the willful and malicious infliction of pain or suffering is caused, permitted or allowed to continue when there is a reasonable remedy or relief."

The task of monitoring the welfare of animals on factory farms falls to the Wyoming Livestock Board. The board's director, Leanne Stevenson, said some of the actions depicted on the Wyoming Premium video appeared to be "definitely beyond the realm of what are condonable practices."

But Rebecca J. Huss, a professor of law at Valparaiso University in Indiana, says that the meat industry still enjoys a good deal of latitude in defining what is "condonable."

"If enough people do it, then it's commonly accepted, even if the general population wouldn't understand or think that it's humane," said Huss, who served as guardian for the abused animals in the 2007 dog-fighting case against professional football player Michael Vick. She cites the common use of gestation crates as an example. "If gestation crates are prevalent, it would take them out of the definition of cruelty, so it's an odd circular reasoning, isn't it?"

According to Emerich, there's a lot of discussion around gestation crates and he suspects the housing system "will probably go away in years to come."

Representatives of factory farms counter that industry norms are based on scientific studies and years of developing best strategies. "The farmers who work with the animals every day, who make animal well-being their top priority, are best able to decide what's good for their animals, not a bureaucrat in the state capital or Washington, D.C.," said Warner, the NPPC spokesman.

What happened at Wyoming Premium, Warner and other industry representatives say, is clearly not acceptable practice. But animal welfare advocates argue that better oversight is still needed.

"Here you have a case where it's not just the fox guarding the henhouse, the fox is actually deciding what the rules of the henhouse are going to be," said the Humane Society's Shapiro. "All that's required is enough farmers to participate in the cruelty to have it exempted from the cruelty laws."

FALLOUT ON THE FARM

In the aftermath of the video's release, DeRouchey said Wyoming Premium invited an independent auditor to tour the facility, along with the farm's veterinarian, to ensure that "the animals that are still there are being well taken care of and there's no more issues, as far as that goes."

Last week, he said, all remaining employees were put through the industry's quality assurance training. "We reiterated that animal abuse is not going to be tolerated," he said. "It's not necessary."

Representatives of the farm's parent company, Itoham Foods of Japan, could not be reached for comment. DeRouchey said he was in contact with Itoham's American subsidiary, Itoham America, and that they were deliberating over next steps.

The website for Wyoming Premium Farms went down shortly after the Humane Society made its video public.

The Humane Society says it provided the video and additional details, which have not been made public, to the Platte County sheriff's department, which in turn requested that the Wyoming Livestock Board lead the investigation. The board will send its findings to the county attorney for review to determine if criminal charges will be filed.

Asked whether the statutes that outline which agencies oversee livestock welfare needed clarifying, Stevenson of the Wyoming Livestock Board said she wasn't sure. "That discussion is a healthy discussion to have," she said. "I can't speak as far as whether the legislatures see a need for changing that, because it has been working the way we have currently been operating.

"It does work," she added. "Should we fix something that's not really broken?”

A month before she began her undercover investigation at Wyoming Premium, the Humane Society's undercover investigator noted that Iowa had made it illegal to gain access to a farm facility under false pretenses.

A handful of other states, including Kansas and North Dakota have related "ag gag" laws, and more are considering similar legislation.

The activist says she remains undeterred, and that she plans to continue conducting undercover investigations.

As for the pigs at Wyoming Premium Farms, she said: "I hope that everything works out on behalf of those wonderful animals that are stuck in there."