Mysterious pig-related foam causes farm explosions in Midwest
14 March 2012
A mysterious foam has been discovered growing in manure pits of Midwestern pig farms that is reported to have been responsible for up to six explosions that have destroyed intensive pig production units and the animals inside.

Foam expanding through a vent from a farm manure pit
The gelatin-like material can expand four feet high and trap gases such as methane, which causes catastrophic explosions when an ignition source is present.
According to a report in the Minnesota Daily, half a dozen barns in the Midwest have exploded since the foam was first discovered in 2009. In mid-September 2011, a barn in Iowa exploded causing the death of 1,500 hogs and injuring a farm worker.
Researchers from the University of Minnesota are now looking into what may be causing the formation of the foam. There is speculation that a new species of bacteria has evolved within manure pits in recent years.
Researchers have also noticed a correlation between foam growth and the use of dried distillers’ grain, a byproduct of ethanol production containing antibiotics, in pig feed.