Minnesota’s hog farming industry has been stricken by a string of gruesome incidents in recent days, raising concerns about the practice known as factory farming.

The JBS Swift kill line was shut down for 14 hours on Wednesday. Rumors suggest a USDA inspector ordered the shutdown after an alleged inhumane kill. Regardless of the cause, the effect was a line of trucks filled with pigs left waiting outside of the facility in 90-degree heat.

One truck driver was quoted by the Worthington Daily Globe as saying, "There are going to be a lot of deads."

In another incident, a fire ripped through two barns at a large hog farm in Waldorf, Minn., on Tuesday night. Around half of the pigs in the facility — 1,200 of 2,400 –  were killed.

Earlier this month, 400 pigs and an undetermined number of piglets perished in a fire near the town of Dexter, Minn.

These giant hog farms are known as concentrated animal-feeding operations (CAFO). A CAFO is loosely defined as any agricultural operation where a large number of animals are kept and raised in confined situations for more than 45 days in a 12-month period.

CAFOs frequently divide rural ag-based communities. Economic pressures on farmers to produce in large quantities often collide with concerns over air quality, manure runoff and animal wellfare.

In 2006, I had the opportunity to visit a CAFO in Michigan of similar size to the one in Waldorf.

Plastic footwear covers were required to tour the facility to prevent the pigs from being exposed to unwanted bacteria. Four barns housed a total of over 2,400 hogs with little moving room. The huge barns each held 600 pigs, and each barn was divided into 24 pens, which each contained 25 pigs.  Not far from the pens, a reservoir of manure over 10 feet deep lay behind a large berm. The manure was sold and applied as fertilizer.