There is nothing else like it in the world - a giant farm factory churning out 5,000 slaughter-ready hogs a week with conveyor-belt precision.

Some say Circle Four Farms is the first - and maybe the last - of its kind.The operation is the country's largest so-called integrated hog farm. By the end of the decade, if all goes as planned, it will be the world's largest, capable of producing 2.5 million hogs a year.

Now, some 30,000 genetically selected sows, each good for more than two litters a year, are artificially inseminated. After weaning, the piglets are moved to giant nurseries where they are given a special diet until they reach 50 pounds. Then they are transferred to "finishers" - barns twice the length of a football field containing nearly 4,000 hogs apiece.

Automatically fed and watered, the hogs grow to roughly 250 pounds in 120 days. Then they are herded into trucks and driven nine hours to the Farmer John's slaughterhouse and packing facility outside Los Angeles.

"Most are destined to be Dodger Dogs," Farmer John's trademark hot dog, said Circle Four developmental director Rob Adams.

From birth to slaughter, the hogs never are out of doors. To reduce the potential spread of disease, workers must shower and don clean overalls before entering a barn. Quarantines of a few hours to three days are required for those traveling between barns.

Waste from the barns drains into giant, open-air sewage lagoons, some containing up to 27 million gallons.

Grain from Iowa and Nebraska is shipped by rail to Milford, where Circle Four grinds 3,000 tons a week into feed pellets at its own mill.

The Beaver County site was chosen because of its proximity to the West Coast market. Eventually, hogs from Circle Four could find their way to the Pacific Rim.

Currently, the farm is operating a single, so-called "pyramid" of approximately 265,000 hogs, called the Skyline Complex. Circle Four plans three more just like it along a 25-mile corridor stretching into Iron County to the south and Millard County to the north.

Eventually, Circle Four may also build a slaughterhouse and processing facility, although Adams said those plans are on hold.

Nancy Thompson, an analyst with the Center for Rural Affairs in Walthill, Neb., which monitors corporate hog farming, says the giant integrated farms may be obsolete even as they've gained popularity.

Backlash from environmental problems associated with the open sewage lagoons already has other states like Wyoming, South Dakota and Missouri - the site of the only farm even close to the size of Circle Four - moving to regulate them.

"They're facing difficulties wherever they build them," she said.

She predicts states that don't attempt to control the giant farms will find themselves scrutinized by the Environmental Protection Agency.

Thompson said states make the mistake of attempting to regulate corporate farms as agriculture instead of industry.

"It's laughable even to call it a farm," she said. "It's an industry that produces hogs instead of widgets."