I'm no expert on hog farming, but it seems to me that when whatever you're doing is creating explosive poop foam that has destroyed barns and killed thousands of hogs you might be doing something wrong.
Tom Philpott at Mother Jones reports on this disgusting phenomenon:
As manure breaks down, it emits toxic gases like hydrogen sulfide and flammable ones like methane, and trapping these noxious fumes under a layer of foam can lead to sudden, disastrous releases and even explosions. According to a 2012 report from the University of Minnesota, by September 2011, the foam had "caused about a half-dozen explosions in the upper Midwest…one explosion destroyed a barn on a farm in northern Iowa, killing 1,500 pigs and severely burning the worker involved."
And the foam grows to a thickness of up to four feet—check out these images, from a University of Minnesota document published by the Iowa Pork Producers, showing a vile-looking substance seeping up from between the slats that form the floor of a hog barn. Those slats are designed to allow hog waste to drop down into the below-ground pits; it is alarming to see it bubbling back up in the form of a substance the consistency of beaten egg whites.
And here's the catch: Scientists can't explain the phenomenon.
Last year, following the the explosion that killed 1,500 hogs, Sami Grover wrote "When pigs start exploding, it is time to rethink our food system... 2,000 pigs in one building - is it any wonder that something was going to give?"
Read the rest of Philpott's post at Mother Jones for some theories on what is causing the foam and a possible solution.