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Validation of Near-Infrared Reflectance Spectral Data for Analyzing Horse Manure

Can Near-Infrared Reflectance Spectroscopy (NIRS) Be Used For Analyzing Horse Manure?

Increased horse numbers and insufficient acreage limit the ability for on-farm use of horse manure. Nearly 58% of surveyed farmers in NJ indicate that some manure was disposed off-farm while only 54% spread any manure on the farm (Westendorf et al., 2010). Analysis of manure by Near-Infrared Reflectance Spectroscopy (NIRS) could be a useful means of determining nutrient and energy content without time consuming efforts of wet chemistry and other laboratory analyses if horse manure is used as a fertilizer or energy source. The NIRS analysis works by subjecting samples to a concentrated light of a known spectrum and measuring the absorbance of the reflected beam (Dyer and Feng, 1997). Covalent chemical bonds of the common organic elements (Carbon, Nitrogen, Oxygen and Hydrogen) have strong absorbance in the NIRS region, useful because there is a correlation between absorbance and concentration (Malley et al., 2002). By comparing data between samples generated by NIRS to laboratory analysis of the same samples, NIRS equipment can be calibrated for practical use. The objectives of this project were: 1) determine the nutrient content and value of horse manure, and make NIRS calibrations based on previously determined wet chemistry values, and 2) determine if ash or Neutral Detergent Fiber (NDF) content can be used to predict Gross Energy (GE) levels.

What did we do?

Horse manure consisting of 123 solid dry stack manure samples, were collected from 30 NJ farms over four seasons during a 12-month period in 2008-2009. Samples were collected from various random locations in a manure pile in ~ 4 l sealable plastic bags, frozen, and stored until analysis. All samples were dried at 55o C to a constant weight in a Thermocore® oven. Following drying, all samples were ground to a particle size of 5-10 mm in a Waring® industrial blender, referred to as Coarse ground samples. Samples were sent to DairyOne Laboratories in Ithaca, NY and analyzed for manure components (Total-N, P2O5, K2O, NDF, and GE); samples were analyzed for Ash by the Rutgers University Soil Testing Laboratory. Coarse ground samples were further ground in a coffee grinder to a particle size between 2-3 mm (these samples are referred to as Fine ground samples). All NIRS analysis of Coarse and Fine ground samples were made with a Unit y Scientific Spectrastar ™ 2400 Drawer model (Brookfield, CT). Samples were scanned at 1nm intervals over the wavelength range of 1250-2350 nm, as prescribed by Unity Scientific. Data from the DairyOne Laboratory results were used as reference values to develop calibrations using the Ucal™ software package (Unity Scientific, Brookfield, CT) set at default values using a partial linear squares statistical model.

What have we learned?

On a dry matter basis (Table 1) samples averaged 1.3% N, 1.1% P2O5, 1.5% K2O, 69.2% NDF, 3800 kCal/g GE, and 24% Ash. The NIRS equations (Table 2) for Coarse (5-10 mm) ground horse manure predicted nutrient content, R-squared values of 0.76, 0.71, 0.69, 0.46, 0.77, and 0.87 for N, P2O5, K2O, NDF, GE, and Ash, respectively. The NIRS also predicted Fine (2-4 mm) ground horse manure R-squared values of 0.83, 0.55, 0.50, 0.57, 0.89, and 0.92 for N, P2O5, K2O, NDF, GE, and Ash, respectively. Ash, GE and NDF were regressed to determine how effectively Ash and NDF would predict GE (Table 3); NDF was a poor predictor of GE content (R-squared of 0.32), while Ash was a good predictor (R-squared of 0.96).

Future Plans

This research suggests that NIRS can be useful for predicting nutrient content of horse manure and that Ash is a good predictor of energy content. A comparative field trial on horse farms is planned for follow-up.

Authors

Michael L. Westendorf. Extension Specialist in Animal Science. Rutgers, the State University of New Jersey westendorf@aesop.rutgers.edu

Zane R. Helsel. Extension Specialist in Plant Biology and Pathology. Rutgers, the State University of New Jersey.

Additional information

Author Contact Information:

Michael Westendorf

Rutgers, The State University of New Jersey

84 Lipman Drive

New Brunswick, NJ 08901

Phone: 848-932-9408

e-mail: westendorf@aesop.rutgers.edu

Reference:

Dyer, D. J. and P. Feng. 1997. NIR Destined to be Major Analytical Influence. Feedstuffs Magazine. November 10, 1997.

Malley, D.F., Yesmin, L., and Eilers, R. G. 2002. Rapid Analysis of Hog Manure and Manure- amended Soils Using Near-infrared Spectroscopy. Soil Science Society of America Journal. 2002. 1677-1686.

Westendorf, M. L., T. Joshua, S. J. Komar, C. Williams, and R. Govindasamy. 2010. Manure Management Practices on New Jersey Equine Farms. Prof. Anim. Sci. 26:123-129.

Acknowledgements

Supported in part by the State Equine Initiative. Rutgers Equine Science Center. New Jersey Agricultural Experiment Station.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Relationship between Surface Waters and Underlying Stream and Ditch Sediment in Selected Eagle Creek Tributaries


Why are stream and ditch sediment important to water quality?

Best management strategies implemented in most watersheds to reduce phosphorus (P) loads to surface waters have been successful, however, internal P loading within streams and ditches may still provide P to overlying water. Phosphorus retention and release by sediments is important for understanding sediment P status and buffering capacity and for determining the potential environmental fate of sediment bound P in flowing water systems.

What did we do?

Eight headwater streams and drainage ditches within Eagle Creek Watershed in central Indiana were selected to evaluate soluble P (SP). Stream and drainage ditch water and sediment were collected monthly from 8 selected locations within the Eagle Creek watershed in central Indiana for two consecutive years to estimate if there were any seasonal and/or land use trends. Sediments and water were analyzed for soluble P, and 24-hour P isotherms were performed to determine the P sorption capacity and to calculate the equilibrium P concentration (EPC0). The relationship between  EPC0 and SP in the water column allows for the prediction of the potential for sediments to either release P to or retain P from the water column.

What have we learned? 

Surface water P concentrations varied seasonally and were consistently greater during summer (P<0.05). Surface water SP concentrations increased with the percentage of land classified as urban (P<0.0001). Generally, we observed lower P concentrations in sediment during summer and greater P concentrations during winter and spring. We also observed greater P concentrations in areas that had a greater percentage of land used for agriculture and in some cases, sub-catchment area influenced the P content that was observed. Sediment EPC0 concentrations were not related to water column SP, however, when sediments were separated as ‘sinks’(r = 0.49) or ‘sources’(r = 0.65), a strong correlation was found between sediment EPC0 and water column SP (P<0.0001).

Future Plans    

Information from this study will assist managers and planners in targeting areas with the greatest potential for loss of P from sediments to overlying water. These results will also assist in improving nutrient criteria thresholds for the watershed.

Authors      

Candiss O. Williams, Research Soil Scientist, USDA NRCS Kellogg National Soil Survey Laboratory & Research Candiss.Williams@lin.usda.gov

Brad Joern, Professor, Department of Agronomy, Purdue University Douglas R. Smith, Research Soil Scientist, USDA ARS Grassland, Soil, and Water Research Laboratory

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Analyses of Microbial Populations and Antibiotic Resistance Present in Stored Swine Manure from Underground Storage Pits

 

Why Study Antibiotic Resistance in Manure?

Antimicrobial compounds have been commonly used as feed additives for domestic animals to reduce infection and promote growth. Recent concerns have suggested such feeding practices may result in increased microbial resistance to antibiotics, which can have an impact on human health. As part of our research project we have been studying the commensal microbial populations present in stored swine manure and the swine GI tract. We have extended this work to include studies on the antibiotic resistance present in these populations.

What did we do?

Predominant microbial populations were identified by both pure culture isolations and direct 16S rDNA sequencing of total DNA from swine feces and stored manure samples. Antibiotic resistance was analyzed using similar pure culture isolation methods. Pure cultures were isolated following plating on anaerobic and aerobic media containing tetracycline, tylosin, or erythromycin. Polymerase chain reaction (PCR) analyses using primers based on a variety of antibiotic resistance genes was carries out with both pure culture isolates and total DNA from swine feces and stored manure.

What have we learned?

Results of pure culture isolation and direct 16S rDNA gene sequence analyses indicate that the bacterial populations of the swine GI tract (feces) and stored manure ecosystems are predominantly composed of anaerobic, low mole %G+C, Gram-positive bacteria, most of which represent novel genera and species. Results of antibiotic resistance gene PCR studies demonstrated the presence of a variety of tet (e.g., tetK, tetO) and erm (e.g., ermA, ermC) resistance gene classes in both anaerobic and aerobic pure cultures and total DNA from both swine feces and stored manure, as well as the identification of novel bacteria containing new resistance genes. Comparison of DNA sequences suggests that horizontal transfer of resistance genes between bacterial strains has also occurred. The data indicate that both the swine gastrointestinal (GI) tract and stored swine manure may serve as reservoirs of known and novel antibiotic resistant bacteria and resistan ce genes.

Future Plans

We are interested in developing methods to reduce antibiotic resistance in the swine GI tract and stored manure, and to determine if antibiotic resistance genes present in these ecosystems can be transferred to bacteria that may affect human health (e.g., E. coli, Salmonella, Campylobacter).

Authors

Terence R. Whitehead, Research Microbiologist, USDA-ARS- National Center for Agricultural Utililzation Research, Peoria, IL 61604 terry.whitehead@ars.usda.gov

Michael A. Cotta, USDA-ARS-National Center for Agricultural Utilization Research, Peoria, IL 61604

Additional information

Terence R. Whitehead, NCAUR, 1815 N. University St., Peoria, IL 61615 309-681-6272

USDA-ARS-NCAUR-Bioenergy Research Unit: http://ars.usda.gov/main/site_main.htm?modecode=50-10-05-20

Cotta, M.A., Whitehead, T.R., and Zeltwanger, R.L. Isolation, Characterization, and Comparison of Bacteria from Swine Faeces and Manure Storage Pits. (2003) Env. Microbiol. 5:737-745. http://onlinelibrary.wiley.com/doi/10.1046/j.1467-2920.2003.00467.x/pdf

Whittle, G., Whitehead, T.R., Hamburger, N., Shoemaker, N.B., Cotta, M.A., and Salyers, A.A. Identification of a new ribosomal protection type of tetracycline resistance gene, tet(36), from swine manure pits . (2003) Appl. Environ. Microbiol. 69:4151-4158. http://aem.asm.org/content/69/7/4151.full

Cotta, M.A., Whitehead, T.R., Falsen, E., Moore, E. and Lawson, P.A. Robinsonella peoriae gen.nov., sp. nov., isolated from a swine-manure storage pit and a human clinical source. (2009) Int. J. System. Evol. Microbiol. 59:150-155. https://pubmed.ncbi.nlm.nih.gov/19126740/

Whitehead, T.R. and Cotta, M.A. Stored Swine Manure and Swine Feces as Reservoirs of Antibiotic Resistance Genes. (2013) Lett. Appl. Microbiol. 56:264-267. http://onlinelibrary.wiley.com/enhanced/doi/10.1111/lam.12043/

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Measuring Pasture Dry Matter Intake of Horses


Why Is It Important to Accurately Measure Horse Dry Matter Intake?*

The ability to predict a horse’s rate of pasture dry matter intake (DMI) assists horse owners/managers in accounting for pasture’s contribution toward a horse’s daily nutrient requirements. Accounting for nutrients obtained from pasture improves the ability to accurately balance rations thereby preventing inefficiencies associated with over- or under- feeding nutrients. This presentation will review pasture DMI estimates for horses reported in scientific literature, sources of variation associated with the measurements, and methods used to measure pasture DMI.

Pasture dry matter intake varies considerably. Estimates for continuously grazing horses range from 1.5 to 2.5% of body weight in dry matter (DM). Factors contributing to variability in pasture DMI include herbage mass available for grazing, sward height, plant maturity, plant chemical composition, plant palatability, horse physiological status and time allowed for grazing. Dry matter intake tends to increase as pasture herbage mass increases, provided forage does not become over-mature. Sward height may also play a role in dry matter intake as it can influence harvest efficiency (e.g., bit size and rate of chewing necessary to swallow ingested forage). Level of plant maturity and sward height are also related to plant chemical composition. As plants reach maturity acid detergent fiber (ADF) and neutral detergent fiber (NDF) increase. Both ADF and NDF concentration are negatively correlated to a horse’s preference for forage. Plant nonstructural carbohydrate (NSC) has been reported to be positively correlated with horse pasture plant preference. Therefore plant chemical composition (ADF, NDF, NSC) influences horse preference and likely influences pasture DM intake. Dry matter intake is also influenced by horse physiological status. Horses having physiological states with nutrient requirements above maintenance may also have greater pasture dry matter intakes (e.g., lactating mares). Dry matter intake is also influenced by the amount of time a horse is allowed to graze. As the amount of time allowed for grazing is restricted a horse’s rate of dry matter intake increases. Therefore it is possible in some cases for horses to have restricted pasture access yet still consume a significant amount of forage DM due to an increased rate of DMI.

What Did We Do?

Several methods exist to measure pasture intake among grazing horses, yet none are perfect and all face challenges in their application. The primary methods are herbage mass difference, difference in BW pre- versus post-grazing, and marker techniques (e.g., alkanes, acid-insoluble ash etc…). Herbage mass difference measures the herbage mass prior to grazing and again following grazing. This is accomplished by harvesting multiple small forage sub-samples each having the same area (e.g., a sub-sample is harvested within a .25 m x .25 m frame at a height of 2.5 cm above the ground). The difference between pre- and post-grazing herbage mass reflects the amount of forage consumed by the horse. However, as the time between pre- and post-grazing increases, pasture re-growth contributes to error in this measurement. An additional source of error in this measurement results from variability in sub-samples used to predict pre- and post-grazing herbage mass. Therefore this met hod tends to work best in small areas where grazing takes place less than 12 h. Change in body weight during a grazing bout, corrected for fecal, urine and other water loss, is another method used to predict dry matter intake. However, this method requires an efficient means of collecting feces and urine (e.g., collection harness apparatus) and requires a livestock scale having a relatively high sensitivity. The sensitivity of many livestock scales is ± 1 kg, which can represent considerable variation for smaller intakes. Chemical markers, either inherent to the plant or provided externally, provide a means of measuring DMI in a natural grazing setting. Markers rely on the following principle: Intake = fecal output/indigestibility. Fecal output is determined by feeding a known amount of an external marker, not present in pasture plants (e.g., even-chained alkanes) and then measuring its dilution in the feces. Indigestibility is calculated as 1 – digestibility. Digestibility is determined by the ratio of a marker concentration within the plant to that in the feces. Internal markers used for estimating digestibility in horses include odd-chained alkanes and acid-insoluble ash. Marker methods provide accurate measures but are relatively expensive and require considerable care when sampling forage (e.g., the composition of forage sampled must reflect the composition of the forage consumed).

What Did We Learn?

Although each of these methods has their short comings they can provide a starting point to estimate dry matter intake. Coupling these estimates with horse performance measures (change in BW or body condition, average daily gain for growing horses) should be used in conjunction with these estimates in order to validate them and correct for their sources of error. Ultimately, these methods can be used to develop models that incorporate factors responsible for variation in DMI among horses to more accurately predict pasture intake thereby facilitating efficient use of pasture derived nutrients in feeding horses.

Author

Paul D. Siciliano is a Professor of Equine Management and Nutrition in the Department of Animal Science, North Carolina State University. He teaches classes in equine management and conducts research in the area of equine grazing management. Paul_Siciliano@ncsu.edu

Additional Information

Chavez, S.J., P.D. Siciliano and G.B. Huntington. 2014. Intake estimation of horses grazing tall fescue (Lolium arundinaceum) or fed tall fescue hay. Journal of Animal Science. 92:p.2304–2308.

Siciliano, P.D. 2012. Estimation of pasture dry matter intake and its practical application in grazing management for horses. Page 9-12 in Proc. 10th Mid-Atlantic Nutrition Conference. N.G. Zimmermann ed., Timonium, MA, March 2012.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Cationic polymer and high-speed centrifugation effects on pathogen reduction during manure solid/liquid separation


Purpose

To investigate the effects on pathogen reduction using cationic polymer and high speed centrifuge during manure solid/liquid separation.

What did we do?

In this study, polymers effects on pathogen reduction were investigated. Low charge density cationic polyacrylamide (CPAM) was selected because CPAM has been commonly used in manure treatment and it is effective for manure coagulation and flocculation. The effect on pathogen reduction of CPAM was studied in this research. High charge density cationic polydicyandiamide (PDCD) was selected because of its application of water clarification and its the extreme high charge.

E. coli and total coliform counts were examined under three different conditions: buffer media only samples, dairy manure samples and polymer amended dairy manure samples. For each condition, the samples were centrifuged at a series of speed from 0×g to 10,000×g.

What have we learned?

The results demonstrated positive impacts of both polymer and high speed centrifugation on lowering the pathogen levels in the liquid portion of the manure. Low charge density CPAM is effective for manure coagulation and flocculation, however, it has a negligible effect on pathogen reduction in either nutrient rich or nutrient deficient conditions. In contrast, highly charged cationic PDCD does not facilitate coagulation in manure with high solids content, but can potentially inhibit bacterial pathogens and further lower the solids content in the liquid portion of manure after CPAM separation.

The results from this study also demonstrated that high speed centrifugation has a notable impact on solids reduction and pathogen reduction for 10 minutes centrifugation retention time. Centrifugation speed around 4,000×g was capable of reducing pathogen levels higher than 90% from a single separation process. However, high speeds above 6,000×g results in minor additional reduction.

Future Plans

This study investigated cationic polymer and centrifuge speed impact on pathogen reduction and solid/liquid separation in dairy manure. However, there is an increasing concern about reactivation issue in centrifugation of mesophilically digested biosolids. Therefore we have attempted to conducted more research in the future regarding parallels to manure digestion. Until recently, it is still not fully understood why some municipal wastewater facilities experienced reactivation of microorganisms in centrifuged solids while others did not. Thus, it is important to investigate the effect of centrifuge speed in combination with polymer type on indicator and pathogen content of manure digests.

Authors

Troy Runge, Professor, Biological Systems Engineering, University of Wisconsin-Madison trunge@wisc.edu

Additional information

Journal papers have been submitted to Journal of Environmental Quality

Troy Runge, trunge@wisc.edu

Zong Liu, zliu73@wisc.edu

Cationic polymer and high-speed centrifugation effects on pathogen reduction during manure solid/liquid separation

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Swine Manure Application Method Impact on Soil Arthropods


Does Manure Application Impact Soil Arthropods? *

Soil arthropod populations and diversity provide an indication of the biological quality of soil, which can impact soil fertility. Arthropods include insects, crustaceans, arachnids, myriapods, and scorpions and nearly every soil is inhabited by many different arthropod species. Row-crop soils may contain several dozen species. One particular arthropod species, mites, can have a significant impact on nutrient release in soil. For this study, the impact of swine manure slurry applied via broadcast and injection at a rate designed to meet the agronomic nitrogen needs of corn was investigated to determine the manure application method impact on soil arthropod population and diversity.

What did we do?

Treatments include broadcasted swine slurry, injected swine slurry, and non-manured check plots with four replications per treatment. Plots have been monitored following manure application in June 2014 and will continue through June 2015. Soil samples were removed 4 d prior to manure application and at 1, 2, and 4 weeks and monthly thereafter from 0 to 8 inches on each plot. Arthropods were extracted by use of Burlese funnels and collected species are being sorted and characterized.

What have we learned?

Species characterization is on-going and will be summarized for presentation in the poster session at the conference.

Future Plans

Results of this work will allow us to better understand the impact of manure application on soil biological properties, a component in defining the overall fertility or “health” of soil.

Authors

Amy Millmier Schmidt, Assistant Professor and Livestock Bioenvironmental Engineer, University of Nebraska – Lincoln aschmidt@unl.edu

Nicole R. Schuster, Graduate Research Assistant, University of Nebraska – Lincoln; Julie Peterson, Assistant Professor and Entomologist, University of Nebraska – Lincoln

Additional information

Dr. Amy Millmier Schmidt; (402) 472-0877; aschmidt@unl.edu

Acknowledgements

We would like to recognize a number of individuals who assisted with soil sample collection, arthropod extractions, and other laboratory activities over the course of this project, including Keith Miller, Ethan Doyle, Mitch Goedeken, Eric Davis, Lucas Snethan, Kevan Reardon and Kayla Tierramar

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Small to Mid-Sized Dairies: Making Compact Anaerobic Digestion Feasible

Why Consider Small or Medium Digester Projects?

Anaerobic digestion (AD) is an environmentally-friendly manure management process that can generate renewable energy and heat, mitigate odors, and create sustainable by-products such as bedding or fertilizer for dairies and farmers. However, due to economics, a majority of commercially available AD technologies have been implemented on large farming operations. Since the average herd size of dairies across the country is below 200 head of milking cows, there is a need for small-scale AD systems to serve this market.

eucolino allen farmsWhat did we do?

The University of Wisconsin-Oshkosh, in collaboration with BIOFerm™ Energy Systems, installed the EUCOlino—a small-scale, mixed, plug-flow digester—onto on a 136 milking head Wisconsin Dairy. The system is pre-manufactured, containerized and requires very limited on-site construction.   This includes grading, pouring a concrete pad for the containers and electrical services installation.

Start-up and commissioning were performed after the delivery of the 64 kWe combined heat and power (CHP). The input materials consist of bedded-pack dairy manure (corn or bean stover and straw), parlor wash water, and minor additional substrates such as lactose or fats, oils, and grease.

Solid materials are dumped via bucket tractor into a hopper feeder system that uses an auger to feed substrate into the anaerobic digestion tank. Additional parlor water is piped directly into the anaerobic digestion tank and mixed with the solids to make a feedstock of approximately 13% total solids. The solids are fed hourly, which is controlled by the PLC system.

The digester has a ~30-day retention time and the biogas produced is stored in a bag above the fermenters. Biogas produced is conditioned and combusted in a CHP mounted on a separate skid. Effluent from the system is pumped directly to an open pit lagoon for storage and subsequently land applied as fertilizer. The system produces approximately 25 – 33 m3/hour of biogas, with a raw biogas quality of 52-60% CH4 and less than 700 ppm H2S.

concrete pads for installation
installation
input

What have we learned?

This project has been an important step forward in developing future small-scale anaerobic digesters across the U.S.  Notably, our installation has given us insight into balancing system economics with the size of small-scale models; the energy output of the system must exceed pre-processing energy requirements and the digester must still be large enough for the designed residence time. Our experience has shown that, while reducing the size of a digester, these requirements remain essential for an installation to economically make sense.

Additionally, challenges involved in AD at the small-scale are related to pre-processing or feedstock conveyance. Once suitable consistence or size for conveyance, anaerobically digesting the organic fraction can be relatively easy. Inconsistency of incoming feedstocks is very detrimental to the system’s stability. Additionally, exterior feedstock storage and above ground piping can limit processing potential when severe cold weather settles in. While all of these are challenges that are easily overcome with engineering, they come at a cost and that can make or break the economics at this scale.

Future Plans

For the small-scale EUCOlino to be effective in the United States, it is key to establishing a U.S.- based manufacturing location. Pre-processing needs to be well-suited to the incoming feedstock. Post-digestion products need established off-takers, for electricity generation, bedding, fertilizer, etc.

Authors

Steven Sell, Manager Application Engineer, BIOFerm™ Energy Systems beaw@biofermenergy.com

Whitney Beadle, Marketing Communications, BIOFerm™ Energy Systems

Additional information

The following publications offer additional information on the Allen Farms digester:

Readers interested in this topic can also visit our website for more information on the Allen Farms digester and other BIOFerm projects. We can also be found on Facebook, Twitter, and LinkedIn.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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The Great Biogas Gusher


Why Pursue Bio-Energy?

The great Texas Oil Boom, also referred to as the Gusher Age, provided for dramatic economic growth in the US in the early 20th century, and ushered in rapid development and industrial growth. Although we typically think of the Middle East when we consider the impacts of oil discoveries on local economies (reference Dubai), at the time of its discovery, the oil finds in Texas were unprecedented; and the US quickly became the world’s top producer of petroleum.

As we all know, the rest of the world came to the party, and the US was soon falling in the ranks of top petroleum producers. Though the US oil reserves are vast, increasing concerns over the environmental impacts of finding, mining, extracting, refining, and consuming fossil fuels has incentivized the development of renewable energy resources, such as solar, wind, hydro, and bioenergy. Of these forms of renewable energy, bioenergy holds the promise for replacement of fossil fuels for transportation use.

a biogas collection systemWhat did we do?

Bioenergy may be described as fuels derived from organic materials, such as agricultural wastes, through processes like anaerobic digestion. The US has even more organic resources above the Earth’s surface than are identified in the petroleum and natural gas deposits yet to be exploited, yet the development of agricultural bioenergy systems seems to be progressing at a snail’s pace, as compare to the great Oil Boom. There is enormous potential in producing biogas from agricultural, industrial, municipal solid waste, sewage and animal byproducts which can be used to fuel vehicles. The EPA estimates that 8,200 US dairy and swine operation could support biogas recovery systems, as well as some poultry operations. Biogas can be collected from landfills and used to power natural gas vehicles or to produce energy. Wastewater treatment plants are estimated by the EPA to have the potential of about 1 cubic foot of digester gas per 100 gallons of wastewater, this energy could potentially meet 12% of the US electricity demand. Industrial, commercial and institutional facilities provide another source of biogas, in particular supermarkets, restaurants, and educational facilities with food spoilage.

What have we learned?

This presentation compares and contrasts the historical development of fossil fuel reserves with the potential for development of bioenergy from agricultural sources, such as animal wastes and crop residues. The US energy potential from these sources is grossly quantified, and current development inhibitions are identified and discussed. Opportunities for gathering biogas and bioenergy from multiple regional sources, similar to the processes used in the Texas oil fields, are discussed. The presentation offers insight into overcoming these obstacles, and how the US may once again rise to the top of the energy development rankings through efficient use and stewardship of our organic resources.

Percentage of waste water treatment plants that send solids to anaerobic digestion broken out by state

Future Plans

Biogas and bioenergy resources present an enormous opportunity for renewable energy development, and progression toward energy independence for the U.S. The U.S. currently has more than 2,000 active biogas harvesting sites, but claims more than 11,000 additional sites can be developed in the U.S., with the potential to power more than 3 million American homes if used to fuel electricity generating power plants. The USDA, EPA and DOE recently created a US Biogas Opportunities Roadmap which is off to a good start, which hopefully will initiate biogas programs, and foster investment in biogas systems to improve the market vitality in each state. To move the process forward, policy-makers, investors and the public need to have improved collaboration and communication on the state level. We need to develop a clear plan and strategy for developing these valuable biogas resources to promote environmental sustainability and economic growth of our b ioenergy sector.

Author

Gus Simmons, P.E., Director of Bioenergy, Cavanaugh & Associates, P.A. gus.simmons@cavanaughsolutions.com

Additional Information           

http://www.cavanaughsolutions.com 1-877-557-8924

http://www.epa.gov/climatechange/Downloads/Biogas-Roadmap.pdf

Acknowledgements      

USDA/DOE/EPA US Bioenergy Roadmap

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Equine Pasture Management Introduction


Purpose*

Sound grazing management strategies for horses have beneficial impacts on horse health, the environment, and the overall cost of keeping horses. This presentation explains how the fundamental principles of horse grazing behavior, horse nutrient requirements, plant chemical composition, and plant physiology are integrated in the development of sound grazing management strategies.

Why Is Pasture Management Important for Horse Operations?

Horses graze continuously and are capable of relatively large nutrient intakes in comparison with their requirements. This “wastage” of pasture nutrients has negative implications on both the cost of feeding horses and horse health. Mature horses, grazing pasture continually, consume on average 2.5% of their body weight in dry matter (DM) per day (range 1.5 to 3%). Therefore a 500 kg horse consumes approximately 12.5 kg DM/d. This level of DM intake represents a significant proportion of a horse’s daily caloric requirements.

Digestible energy (DE) content of grass pasture can range from 1.78 to 2.74 Mcal/kg DM (mean ± S.D., 2.26 ± 0.48 Mcals/kg DM; n = 6959; Dairy One, 2011). Therefore a mature 500 kg horse consuming 12.5 kg DM/d from pasture consumes 28.85 Mcals DE/d, which is 11.58 Mcals greater than required (16.67 Mcals/d). A DE intake of 20 Mcal above maintenance DE is required per kg of BW gain and an increase in 1 body condition score unit requires approximately 18 kg of body weight gain (NRC, 2007).

Given these assumptions the horse in this example would gain just under 1 body condition score unit per month, provided adequate pasture was available. The excess DE intake, and related pasture intake, in the above example is equivalent to approximately 0.7 of a grazing day (i.e., the horse consumes enough DE in 1 d to last 1.7 d). This scenario demonstrates that in some instances continuous grazing regimes, where intake is uncontrolled, can lead to excessive nutrient intake resulting in wasted resources, and contribute negatively to equine health (i.e., excess body condition). Therefore strategies that control and/or account for pasture DM intake should be implemented.

One strategy that can be used to control pasture intake is restricting the amount of time a horse has access to pasture. Restricting pasture access is accomplished by placing horses in dry-lots or by use of a grazing muzzle. It should be noted that horses may still be able to consume a significant amount of forage while wearing a grazing muzzle in place, depending on whether forage is prostrate or erect. Therefore, placing horses in a dry-lot for part of the day may be a more effective practice.

The daily amount of time allowed for grazing in order to match nutrient intake with nutrient requirements (e.g., caloric intake vs caloric requirement) varies with a horse’s physiological state. Mature idle horses, horses at light work (e.g., ridden 2 to 3 times per week), mares in early gestation (less than 5 months), breeding stallions in the non-breeding season can consume their daily DE requirement in 8 to 10 h of grazing well managed pasture (i.e., > 90% ground cover maintained at a height of > 15 cm) during the seasons where pasture is actively growing. Horses having other physiological states can graze the entire day, as pasture intake alone will not likely provide all required nutrients due to their relatively high requirements.

Horses graze selectively, given the choice, which can negatively impact a plant’s ability to re-grow and ultimately to persist. Horses tend to avoid grazing extremely mature pasture grasses, particularly those areas that are used as latrines. When areas of mature pasture grass are avoided horses concentrate grazing on less mature areas undergoing re-growth. Uneven grazing patterns can also result from horses over-grazing preferred forage in pastures that contain multiple plant species.

Horses show considerable preference toward some species (e.g, Kentucky bluegrass) as compared to others (e.g., tall fescue). The net result of uneven grazing is two-fold, wasted forage in one area and over-grazing in others. Prevention of uneven grazing and its consequences can be achieved by rotational grazing. Rotational grazing strategies allocate an area of pasture containing an amount of dry matter that will last a given number of horses 1 to 7 days and then horses are moved to a new area. This strategy forces horses to graze more uniformly.

The allocation process used in rotational grazing can also be used to limit intake to an amount that provides only the daily requirement thus preventing the problem of excessive pasture nutrient intake, such as that illustrated in the previous paragraph.

A sound grazing management plan manages grazing behavior in manner that attempts to match nutrient intake with nutrient requirements while simultaneously minimizing selective grazing and over grazing.

Authors

Paul Siciliano is a Professor of Equine Management and Nutrition in the Department of Animal Science at North Carolina State University where he teaches courses in equine management and conducts research dealing with grazing management of horses. Paul_Siciliano@ncsu.edu

Additional information

Chavez, S.J., P.D. Siciliano and G.B. Huntington. 2014. Intake estimation of horses grazing tall fescue (Lolium arundinaceum) or fed tall fescue hay. Journal of Animal Science. 92:p.2304–2308.

Bott, R.C., Greene, E.A., Koch, K., Martinson, K.L., Siciliano, P.D., Williams, C., Trottier, N.L., Burke, A., Swinker, A. 2013. Production and environmental implications of equine grazing. J. Equine Vet. Sci. 33(12):1031-1043.

Glunk, E.C., Pratt-Phillips, SE and Siciliano, P.D. 2013. Effect of restricted pasture access on pasture dry matter intake rate, dietary energy intake and fecal pH in horses. J. of Equine Vet. Sci. 33(6):421-426.

Dowler, L.E., Siciliano, P.D., Pratt-Phillips, S.E., and Poore, M. 2012. Determination of pasture dry matter intake rates in different seasons and their application in grazing management. J. Equine Vet. Sci. 32(2):85-92.

Siciliano, P.D. and S. Schmitt. 2012. Effect of restricted grazing on hindgut pH and fluid balance. J. Equine Vet. Sci. 32(9):558-561.

Siciliano, P.D. 2012. Estimation of pasture dry matter intake and its practical application in grazing management for horses. Page 9-12 in Proc. 10th Mid-Atlantic Nutrition Conference. N.G. Zimmermann ed., Timonium, MA, March 2012.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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Time-Temperature Combinations for Destruction of PEDv During Composting


*Purpose

The purpose of this project was to determine the appropriate time-temperature combinations required for inactivation of the porcine epidemic diarrhea virus (PEDv) in composting material as a basis for evaluation of composting for disposal of swine mortalities and/or other PEDv-positive biological material.

What did we do?

In vitro propagation of PEDv for laboratory survivability assays was conducted using a cell culture-adapted isolate received from APHIS-NVSL (Ames, IA) that was free of extraneous agents (5th passage Colorado 2013 PEDv 1303). Propagation was conducted by infection of confluent VERO cell monolayers at a multiplicity of infection (MOI) of 0.1 with a concentration of 5 µg/mL TPCK trypsin. Virus stocks were be amplified following a 2-4 day incubation period on cell monolayers, frozen and thawed, centrifuged, and culture supernatants containing virus were harvested. Virus concentration was calculated and standardized to 1×105-1×106 TCID50/mL using immunocytochemistry and indirect fluorescent antibody assay (IFA) using a PEDV specific mouse monoclonal antibody (MedGene Labs).

The effect of temperature on survivability of PEDv in compost material was evaluated by inoculating compost material and subjecting the material to temperatures of 50°C (122°F), 55°C (131°F), 60°C (140°F), 65°C (149°F), and 70°C (158°F) for 0, 24, 48, 72, 96 h, and 120 h. Sawdust was acquired from a commercial source, autoclaved to eliminate existing microbes, oven dried and used to simulate compost material. One gram of prepared sawdust was placed in each of 140 1-mL centrifuge tubes. Cell culture supernatant containing infectious PEDv was added to phosphate buffered saline and added to each tube achieve a moisture content of 50% w.b. Tubes were randomly assigned to laboratory incubators at the five temperature treatment levels. At each sampling point, four tubes were removed from each incubator and tested to determine virus survivability.

PEDv survivability was determined via two independent assay methods. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a rapid and sensitive method that was used by the Nebraska Veterinary Diagnostic Center to quantify the amount of virus RNA genome in the samples. To validate results from the RT-qPCR in laboratory assays, sawdust simulated compost matrix was spiked with known concentrations of PEDv target RNA and compared to known standards to ensure no inhibition was present and that proper extraction methods were being used. An alternative method using virus isolation was also conducted to determine whether viable virus was present in tubes at a smaller subset of time points. To do this, Vero cell monolayers were infected with filter sterilized aliquots of compost exudate, blindly passaged once after seven days, and examined for virus presence using IFA with a PED specific monoclonal antibody. At specific time points, RT-qPCR Ct values and Virus Isolation were run in parallel to ensure sensitivity of testing and to evaluate correlation of the testing modalities under the simulated testing conditions and matrices.

What have we learned?

At the time of proceedings submission, results were not available for inclusion in this report. Results will be presented during the scheduled oral seminar at the conference.

Results of this laboratory study will be used to evaluate appropriate time-temperature combinations necessary during swine mortality composting to inactivate the PEDv virus and determine the feasibility of on-farm mortality composting as a biosecure disposal method for PEDv-infected pigs. Following this laboratory study, mortality composting was initiated using PEDv-positive piglets to confirm the inactivation of PEDv during composting.

Future Plans

Results of this and the full-scale composting study will be used to recommend appropriate swine mortality disposal methods for swine producers with losses due to PEDv as part of their farm biosecurity plan. Additional swine enteric corornaviruses will likely be studied to confirm similar requirements for disposal of mortalities caused by these viruses.

Authors

Amy Millmier Schmidt, Assistant Professor and Livestock Bioenvironmental Engineer, University of Nebraska – Lincoln aschmidt@unl.edu

J. Dustin Loy, Assistant Professor, Clayton Kelling, Professor, Judith Galeota, Virology Laboratory Manager, and Sarah Vitosh, Graduate Research Assistant, Veterinary & Biomedical Sciences, University of Nebraska – Lincoln

Additional information

Dr. Amy Millmier Schmidt
(402) 472-0877
aschmidt@unl.edu

Acknowledgements

The authors would like to acknowledge the Nebraska Pork Producers Association and the National Pork Board for providing funding for this research. Special thanks to Jared Korth for helping with laboratory activities on this project.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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