Foaming Pig Manure A New Threat in The Pig Industry

Pig manure foaming up through vent on outside of barn. Photo courtesy: Iowa Pork Producers Association.

I'm no expert on hog farming; but, I am an expert about the things I feel are safe; and, things I feel are not safe. This blog deals with an issue I think everyone who eats meat should be aware of. It is one of those things that for some reason - paranoia probably - convinces me (yet, again) that the food industry goes out of its way to hide the issues from the public.

Ever heard of exploding pig poop? Not many people have; but, it is an issue in approx. 25% of factory-farmed piggeries. It appears to me that if something that is just supposed to lay around and smell bad is suddenly starting to percolate, foam and become explosive there may be a bit of a problem here. At the very least, I think that all pork eaters should rethink their eating habits.

David Schmidt: Foaming Manure Pits from Iowa State University Extension on Vimeo.

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?"

One of the present theories that seems viable as the cause of this phenomena is the practice of feeding hogs distillers grains, the mush leftover from the corn ethanol process. Distillers grains entered hog rations in a major way around the same time that the foam started emerging; and, manure from hogs fed distillers grains contains heightened levels of undigested fiber and volatile fatty acids — both of which are emerging as preconditions of foam formation. However, it seems unlikely that distillers grains is the sole cause. Research has shown that on some operations the foam will emerge in some buildings; but, not others even though all the hogs receive the same feed mix.

But if the causes of manure foam remain a mystery, one solution seems to be emerging. A solution that scares me to death, personally. The solution is apparently to dump a bit of monensin (an antibiotic widely used to make cows grow faster)directly into the foam-ridden pit. Remember the problems with growth hormones being used in food animals - early menopause for girls, early puberty for boys, unusual growth, unusually early breast development in young girls, etc.? At rather low levels (25 pounds of the stuff per 500,000 gallon pit) the stuff effectively breaks up the foam, likely by altering the mix of microbes present. No other treatment has been shown to work consistently.

Thankfully, monensin isn't used in human medicine. Still, it's striking to consider that the meat industry's ravenous appetite for antibiotics has now extended to having to treat hog shit with them.

Read the rest of Philpott's post at Mother Jones for some theories on what is causing the foam and a possible solution.

BTW - am I just a simple-minded fool or does no one else think distillers grains -> fermentation process -> pigs eat daily -> some of them good bacterias that causes fermentation is expelled in the piggy poop ->fermentation process starts anew in the comforting warmth of an overcroweded pig barn?