It’s a sad statistic, but every year people and Ilivestock become ill or die, due to breathing high levels of dangerous gases released from manure while agitating and pumping manure from deep-pitted barns.

With crops soon coming out of the fields, manure pumping and incorporation into fields will follow. Manure serves as an excellent source of several key nutrients and is a soil amendment; thus, it is very beneficial to cropland. Additionally, with fertilizer’s increasing costs, manure has an increasingly important economic value today. However, caution and good management practices are important during this time to ensure that pigs and people are not harmed.

As manure decomposes, a variety of gases, including hydrogen sulfide, methane, ammonia and carbon dioxide, are produced. When manure is agitated during pump out, these gases are quickly released, which causes their levels to spike in the surrounding atmosphere. This can create toxic, oxygen-deficient, and even explosive, conditions in the manure pit and the building above. A number of factors influence the concentration of these gases, such as the animals’ diet, air temperature, surface area of the manure and ventilation.

The only guaranteed way to provide safety for people and animals during pit agitation and pumping is to remove them from barns during this period. Unfortunately, due to issues with timing and ability to apply manure, this often is not possible. To reduce the risk of exposure to hazardous pit gases, however, here are some recommendations you should follow:

  • Never allow people to enter a building while it is being pumped. Consider using a physical barrier or warning device of some sort to prevent entry. Our University of Minnesota Swine Extension group collaborated with the Minnesota Pork Board to develop printed warning tags to place on barn doors. To download and print these signs free of charge, go to
  • A person should be at the site, but outside the building, during pumping to monitor the process. This person should have a copy of the emergency plan and emergency contact information for the site.
  • Consider minimal or no agitation until the manure level is at least 1 to 1.5 feet below the support lintel at the pump-out/fan ports. This allows the pit fans to effectively exhaust gases.
  • Avoid aggressive agitation when animals are in the building, as it increases gas release.
  • Do not uncover pump-out ports unless necessary for agitation and manure load-out. When uncovered, these ports act like large air inlets and may result in inadequate air movement in other parts of the building.
  • Cover the pump-out opening around the agitator with a tarp to reduce or minimize this opening as a fresh-air inlet into the animal space.
  • For curtain-sided barns during warm weather, if winds are at least 5 mph, open curtains and run all exhaust fans. If winds are still, leave sidewall curtains closed and run all exhaust fans to draw air down through the floor and out of the building.
  • For curtain-sided barns during cold weather, when pigs are big, leave curtains closed and run all exhaust fans. Reduce static pressure in the animal space by opening ceiling inlets and/or curtains slightly so that less air is likely to be drawn from pump-out port openings into the animal space.
  • Continue to ventilate at an elevated level for 1 to 2 hours after the pump-out process ends.
  • Secure all pit covers after pump-out.

Mike Brumm, president of Brumm Swine Consulting, provided these and other recommendations during a past PorkCast Webcast program. To access and view the complete presentation, go to In addition to an archived recording of the program, a short pit-pumping guidelines checklist and a factsheet on how to develop an emergency action plan are provided.

While following these recommendations does not guarantee animal or human safety, it should greatly decrease the risk of an asphyxiation event occurring during pump-out of deep-pitted barns.
Remember safety first when you pump out barns this fall.