It’s Monday afternoon and I’ve delayed writing this weekend’s blog due to a hectic schedule of telephone calls on Friday. A majority of the calls were related to the many foaming issues many producers in the upper Midwest are reporting in their manure pits.
While there have been occasional reports of pits foaming in previous years, this year the problem seems to be much bigger. On Friday I was on a conference call with a group of ag engineers and animal scientists about the problem. So far, we can find no common thread between sites and/or buildings within a site for the problem.
In general, the foam seems to be coming up thru the slats (or growing in depth under the slats) faster when there are no pigs in a facility. This is most likely due to the fact that feces, urine and other materials dropping thru the slots in the slats are breaking up the foam bubbles. When the barns are empty, there is nothing to break up the bubbles.
What is so confusing about the whole foam issue is that I have had reports of one room of a double-wide having foam and the other room being fine, or 2 of 4 barns at a grow-fin site having foam. All pigs are the same age, fed the same diet, from the same source, etc. Why one pit foams and another doesn’t is the mystery.
What can producers do about the foam? Again, not many good answers. Some have tried adding 5 gal of diesel fuel at the agitation pump – this doesn’t always work, and it is not environmentally friendly. An alternative that has been tried in past years has been crop oil, but like the diesel fuel, it doesn’t work in all cases. Ag engineers at the University of Minnesota and the University of Illinois are working this week with commercial de-foaming agents such as are used in municipal sewage plants. They are working with cooperating producers to see if any of these products is effective and affordable for dealing with the foaming issue.
In empty facilities, some producers have reported that turning on sprinklers has reduced the foam. At the same time, they all comment that the odor when the foam is reduced is terrible in the facility.
Is the foam contributing to the explosion risk? Again, no good answers. It does appear that the foam is retaining high concentrations of hydrogen sulfide, mercaptans and methane in the unburst bubbles. If the foam is retaining these explosive compounds, in cases of minimal or no ventilation do they get to high enough levels to be explosive when a spark is provided? Again, no good answers. Methane and hydrogen sulfide are explosive at 4% or 40,000 ppm. Hydrogen sulfide is deadly at much lower levels. The nose becomes insensitive to it around 150-200 ppm and by 500 ppm it causes death.
At this point in time, the recommendation is to always have ventilation operating when doing anything with a manure pit, even if the barn is empty. Turn off all pilot lights, feed augers, etc so they don’t provide an ignition source. Hang lock-out tags on all entry points to the facility (available from your state pork producer association office or National Pork Board). Don’t agitate manure until it is 2 ft below the slat so that pit fans have enough head room to function in assisting ventilating the pits. Don’t break the surface with agitation as this has been proven to significantly increase the release of gas from a pit.
All of these cautions sound good when written, but in the next 5 weeks I’m sure a lot of mistakes will be made. All of the rain delays have meant that no manure has been pumped for 2-3 weeks in the upper Midwest. At some sites, even if the manure crew was ready and the ground was dry, the corn or beans weren’t out yet so no place to go with the manure.
Assuming a normal fall freeze-up, injection of manure on crop ground will have to be completed by Thanksgiving for much of the Midwest. This means in the next 5 weeks, over 60% of all the manure in grow-finish barns in the US must be land applied if it is to be injected. At the same time, we’re fighting to get crops out of the field and fall tillage done. This suggests that mistakes will be made in the rush to completion. My plea – even if you are pressed for time, be sure and take the safety precautions necessary when dealing with manure. Haste does not make waste in this case. Haste and waste equal the risk of tragic circumstances.