Taking manure pit samples in deep-pitted barns on several hundred company-owned and contracted farms is a huge task, but the payoff is huge, too.
There are many practical reasons why pork producers should take manure pit samples, according to Tim Laatsch, director of Environmental Services for The Maschhoffs, based in Carlyle, IL.
For starters, taking samples of their entire network of grower farms, as The Maschhoffs just did in August, enables producers to get test results and pinpoint the actual nutrient content of the manure prior to fall field application.
Second, the August sampling gives producers a fairly representative sample of manure content because the pits are likely to be nearly full, Laatsch says.
Last and most importantly, from two years of manure collection work, The Maschhoffs learned to refine their sampling technique so the process could be accomplished safely and more efficiently.
“Our preliminary research tells us, basically, that we can collect core samples from the exterior pump-out ports on the barn and approximate very closely the agitated mean of the barn,” he says.
This new process also standardizes the sampling and testing process across the system, providing uniform results, while safeguarding farm biosecurity.
“It is clear we want to stay outside the facility when we are sampling manure, because if you open the door to the barn, you could have all kinds of disease transmission issues,” he says.
Manure collection is done using a vertical profile core sampler without pit agitation. “That's the key advantage of profile cores — no need to agitate,” Laatsch explains.
Only deep-pitted barns — gilt developers, wean-to-finish and feeder pig-to-finish barns — are tested using this method.
Open storage, sow units and nurseries are sampled annually using a different collection method. At the time of application, a sample of manure is drawn off of the pump into a container and sent off for analysis.
Take some precautions when using the vertical core sampler to pull manure samples from exterior pump-out ports.
“The pump-out ports are typically designed with a sump hole in the bottom, and you have to be careful about sampling that sump hole because that can skew your sample toward a higher solids and higher nutrient rate content,” Laatsch suggests. Profile cores should only take samples from the main floor of the pit structure.
Samples are preserved by packing them in ice or ice packs, 24-30 samples to a Styrofoam container, and shipped overnight to a certified testing laboratory in Indiana (A&L Great Lakes at Fort Wayne). Cost is $100 for overnight shipping, plus typically $35 in lab fees for the analysis. He stresses only certified labs should be used. For a complete list of certified labs in the United States, refer to the Minnesota Department of Agriculture Web site at www.mda.state.mn or call (651) 201-6000.
“Manure testing allows us to do a system-level analysis of the effectiveness of our nutritional strategies for limiting phosphorus,” he states, “and it gives us that core piece of information to go about establishing rates and matching agronomic needs of the crop.”
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It also helps determine the impact of direct-fed microbials on manure nutrient content. MicroSource S (DSM Nutritional Products) is blended into all grow-finish diets at The Maschhoffs, according to Aaron Gaines, company director of Nutrition and Production. The product is used for odor control, reduction in manure solids and improved pig performance (feed efficiency).
Laatsch says DSM also has a direct-added pit product that The Maschhoffs are testing on new farm setups. “It takes a while to get that microbial population established in the pit, and we try to give it a little jumpstart with some good organisms to reduce odors.”
As manure samples are taken, an evaluation is also made of pit surface crusting, volatile solids and the depth of solids that can be remedied with pit agitation, pit treatment products and other strategies.
“Pit sampling enables us to keep a little better finger on the pulse of how the pits are performing, if farms need help and how to target resources better,” he says.
The Maschhoffs own a nine-barn, tunnel-ventilated, deep-pitted, wean-to-finish system near McLean, IL, that is being used for air quality research by the University of Illinois.
Laatsch provides preliminary results on three technologies that were tested in a two-year study just completed at the McLean farm.
One product involved a three-phase, automated pit control system designed to control pit and pig odors. A series of pH probes measure pH levels in the manure, and a controller meters a neutralizing agent into the pit to raise the pH level as needed to reduce odor. A second component is an “oil lid” that is applied to the surface of the manure pit to serve as an organic seal. Material is allowed to drop through, but the oil lid minimizes the exchange of gases from the pit. A third component is an atomizer system that periodically sprays an acid-based oil product onto the pigs and slats to suppress dust and ammonia volatilization. The claim is improved air quality and performance. Laatsch says there was no statistically significant difference in performance between the control and treated groups for the whole system. The three-phase product costs $4.19/pig marketed.
In the study, there were two treated and two control barns that were monitored around the clock for various gases. In fact, levels of hydrogen sulfide actually increased in the treated barns, which may have been due to sulfur content in the oil, he surmises. The good news is that dust was reduced by about 30%, he notes.
A second technology tested involved a pump and treat system. Manure is pumped out of the barn and run through an electrolysis unit that applies electrical current to the manure. Obviously, there are substantial electricity costs to this system, Laatsch relates, and there was no noticeable impact on pig performance or reduction in ammonia or hydrogen sulfide gases.
But there was about a 25% reduction in odor, which the company suggests is due to the electrolysis process breaking down the volatile fatty acids in bacteria, the main components of odor.
A third system only dealt with dust particulate matter. A shroud is placed over the outside of ventilation fans, comprised of a geotextile-type material fitted over an aluminum frame. Exhausted air is forced up and away from the barn. That pocket of circulated air electrostatically charges exhausted dust particles, causing them to drop and stick to the ground, Laatsch explains. Problems include piles of dust accumulating on the shroud or curtain and ground.
Also, since the curtain is not waterproof, rainfall could result in suspension and transportation of dust particulates, potentially leading to water quality issues, Laatsch says.
In the next 18 months of study at the McLean farm, the focus will include management strategies for dust reduction, such as wet-dry feeders and fat in the diet, and evaluating those approaches in a production setting, he says.
Other efforts will review the dust reduction capabilities of the three main technologies studied.
Two filtration technologies will also be studied at the McLean farm, reports Laatsch. University of Illinois scientists are investigating new design configurations for the biofilter to overcome some inherent problems.
Under consideration is an enclosed-type design to preclude rodent access to the media and to incorporate an automated moisture control system to provide better moisture retention than conventional designs.
Laatsch is particularly interested in a high-tech biofilter manufactured by the Skov Company of Denmark. It uses a multi-stage boxed media filtering system that the company claims treats and significantly reduces emissions of ammonia and particulate matter.
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