Hunkering Down for Extreme Events

In this webinar, we will discuss what happens when we plan for extreme events and what happens when they happen unexpectedly. This presentation was originally broadcast on June 18, 2021.

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Hunkering Down for Extreme Events in the Dairy Industry

Colleen Larson, University of Florida (26 minutes)

Presentation Slides

Water quality and extreme flooding

Angela Harris, North Carolina State University (17 minutes)
Presentation Slides

Responding to Unusual Mortality Events

Mark King, Maine Compost School (14 minutes)

Presentation Slides

Questions From the Audience

All presenters (7 minutes)

More Information

Continuing Education Units


Certified Crop Advisers (CCA, CPAg, or CPSS)

View the archive and take the quiz (not available yet). Visit the CCA continuing education page for additional CEU opportunities.


American Registry of Professional Animal Scientists (ARPAS)

View the archive and report your attendance to ARPAS via their website. Visit the ARPAS continuing education page for additional CEU opportunities.

Poultry Mortality Freezer Units: Better BMP, Better Biosecurity, Better Bottom Line.

Proceedings Home | W2W Home w2w17 logo

Purpose

Why Tackle Mortality Management?  It’s Ripe for Revolution.

The poultry industry has enjoyed a long run of technological and scientific advancements that have led to improvements in quality and efficiency.  To ensure its hard-won prosperity continues into the future, the industry has rightly shifted its focus to sustainability.  For example, much money and effort has been expended on developing better management methods and alternative uses/destinations for poultry litter.

In contrast, little effort or money has been expended to improve routine mortality management – arguably one of the most critical aspects of every poultry operation.  In many poultry producing areas of the country, mortality management methods have not changed in decades – not since the industry was forced to shift from the longstanding practice of pit burial.  Often that shift was to composting (with mixed results at best).  For several reasons – improved biosecurity being the most important/immediate – it’s time that the industry shift again.

The shift, however, doesn’t require reinventing the wheel, i.e., mortality management can be revolutionized without developing anything revolutionary.  In fact, the mortality management practice of the future owes its existence in part to a technology that was patented exactly 20 years ago by Tyson Foods – large freezer containers designed for storing routine/daily mortality on each individual farm until the containers are later emptied and the material is hauled off the farm for disposal.

Despite having been around for two decades, the practice of using on-farm freezer units has received almost no attention.  Little has been done to promote the practice or to study or improve on the original concept, which is a shame given the increasing focus on two of its biggest advantages – biosecurity and nutrient management.

Dusting off this old BMP for a closer look has been the focus of our work – and with promising results.  The benefits of hitting the reset button on this practice couldn’t be more clear:

  1. Greatly improved biosecurity for the individual grower when compared to traditional composting;
  2. Improved biosecurity for the entire industry as more individual farms switch from composting to freezing, reducing the likelihood of wider outbreaks;
  3. Reduced operational costs for the individual poultry farm as compared to more labor-intensive practices, such as composting;
  4. Greatly reduced environmental impact as compared to other BMPs that require land application as a second step, including composting, bio-digestion and incineration; and
  5. Improved quality of life for the grower, the grower’s family and the grower’s neighbors when compared to other BMPs, such as composting and incineration.

What Did We Do?

We basically took a fresh look at all aspects of this “old” BMP, and shared our findings with various audiences.

That work included:

  1. Direct testing with our own equipment on our own poultry farm regarding
    1. Farm visitation by animals and other disease vectors,
    2. Freezer unit capacity,
    3. Power consumption, and
    4. Operational/maintenance aspects;
  2. Field trials on two pilot project farms over two years regarding
    1. Freezer unit capacity
    2. Quality of life issues for growers and neighbors,
    3. Farm visitation by animals and other disease vectors,
    4. Operational and collection/hauling aspects;
  3. Performing literature reviews and interviews regarding
    1. Farm visitation by animals and other disease vectors
    2. Pathogen/disease transmission,
    3. Biosecurity measures
    4. Nutrient management comparisons
    5. Quality of life issues for growers and neighbors
  4. Ensuring the results of the above topics/tests were communicated to
    1. Growers
    2. Integrators
    3. Legislators
    4. Environmental groups
    5. Funding agencies (state and federal)
    6. Veterinary agencies (state and federal)

What Have We Learned?

The breadth of the work at times limited the depth of any one topic’s exploration, but here is an overview of our findings:

  1. Direct testing with our own equipment on our own poultry farm regarding
    1. Farm visitation by animals and other disease vectors
      1. Farm visitation by scavenger animals, including buzzards/vultures, raccoons, foxes and feral cats, that previously dined in the composting shed daily slowly decreased and then stopped entirely about three weeks after the farm converted to freezer units.
      2. The fly population was dramatically reduced after the farm converted from composting to freezer units.  [Reduction was estimated at 80%-90%.]
    2. Freezer unit capacity
      1. The test units were carefully filled on a daily basis to replicate the size and amount of deadstock generated over the course of a full farm’s grow-out cycle.
      2. The capacity tests were repeated over several flocks to ensure we had accurate numbers for creating a capacity calculator/matrix, which has since been adopted by the USDA’s Natural Resources Conservation Service to determine the correct number of units per farm based on flock size and finish bird weight (or number of grow-out days) in connection with the agency’s cost-share program.
    3. Power consumption
      1. Power consumption was recorded daily over several flocks and under several conditions, e.g., during all four seasons and under cover versus outside and unprotected from the elements.
      2. Energy costs were higher for uncovered units and obviously varied depending on the season, but the average cost to power one unit is only 90 cents a day.  The total cost of power for the average farm (all four units) is only $92 per flock.  (See additional information for supporting documentation and charts.)
    4. Operational/maintenance aspects;
      1. It was determined that the benefits of installing the units under cover (e.g., inside a small shed or retrofitted bin composter) with a winch system to assist with emptying the units greatly outweighed the additional infrastructure costs.
      2. This greatly reduced wear and tear on the freezer component of the system during emptying, eliminated clogging of the removable filter component, as well as provided enhanced access to the unit for periodic cleaning/maintenance by a refrigeration professional.
  2. Field trials on two pilot project farms over two years regarding
    1. Freezer unit capacity
      1. After tracking two years of full farm collection/hauling data, we were able to increase the per unit capacity number in the calculator/matrix from 1,500 lbs. to 1,800 lbs., thereby reducing the number of units required per farm to satisfy that farm’s capacity needs.
    2. Quality of life issues for growers and neighbors
      1. Both farms reported improved quality of life, largely thanks to the elimination or reduction of animals, insects and smells associated with composting.
    3. Farm visitation by animals and other disease vectors
      1. Both farms reported elimination or reduction of the scavenging animals and disease-carrying insects commonly associated with composting.
    4. Operational and collection/hauling aspects
      1. With the benefit of two years of actual use in the field, we entirely re-designed the sheds used for housing the freezer units.
      2. The biggest improvements were created by turning the units so they faced each other rather than all lined up side-by-side facing outward.  (See additional information for supporting documentation and diagrams.)  This change then meant that the grower went inside the shed (and out of the elements) to load the units.  This change also provided direct access to the fork pockets, allowing for quicker emptying and replacement with a forklift.
  3. Performing literature reviews and interviews regarding
    1. Farm visitation by animals and other disease vectors
      1. More research confirming the connection between farm visitation by scavenger animals and the use of composting was recently published by the USDA National Wildlife Research Center:
        1. “Certain wildlife species may become habituated to anthropogenically modified habitats, especially those associated with abundant food resources.  Such behavior, at least in the context of multiple farms, could facilitate the movement of IAV from farm to farm if a mammal were to become infected at one farm and then travel to a second location.  …  As such, the potential intrusion of select peridomestic mammals into poultry facilities should be accounted for in biosecurity plans.”
        2. Root, J. J. et al. When fur and feather occur together: interclass transmission of avian influenza A virus from mammals to birds through common resources. Sci. Rep. 5, 14354; doi:10.1038/ srep14354 (2015) at page 6 (internal citations omitted; emphasis added).
    2. Pathogen/disease transmission,
      1. Animals and insects have long been known to be carriers of dozens of pathogens harmful to poultry – and to people.  Recently, however, the USDA National Wildlife Research Center demonstrated conclusively that mammals are not only carriers – they also can transmit avian influenza virus to birds.
        1. The study’s conclusion is particularly troubling given the number and variety of mammals and other animals that routinely visit composting sheds as demonstrated by our research using a game camera.  These same animals also routinely visit nearby waterways and other poultry farms increasing the likelihood of cross-contamination, as explained in this the video titled Farm Freezer Biosecurity Benefits.
        2. “When wildlife and poultry interact and both can carry and spread a potentially damaging agricultural pathogen, it’s cause for concern,” said research wildlife biologist Dr. Jeff Root, one of several researchers from the National Wildlife Research Center, part of the USDA-APHIS Wildlife Services program, studying the role wild mammals may play in the spread of avian influenza viruses.
    3. Biosecurity measures
      1. Every day the grower collects routine mortality and stores it inside large freezer units. After the broiler flock is caught and processed, but before the next flock is started – i.e. when no live birds are present,  a customized truck and forklift empty the freezer units and hauls away the deadstock.  During this 10- to 20- day window between flocks biosecurity is relaxed and dozens of visitors (feed trucks, litter brokers, mortality collection) are on site in preparation for the next flock.
        1. “Access will change after a production cycle,” according to a biosecurity best practices document (enclosed) from Iowa State University. “Empty buildings are temporarily considered outside of the [protected area and even] the Line of Separation is temporarily removed because there are no birds in the barn.”
    4. Nutrient management comparisons
      1. Research provided by retired extension agent Bud Malone (enclosed) provided us with the opportunity to calculate nitrogen and phosphorous numbers for on-farm mortality, and therefore, the amount of those nutrients that can be diverted from land application through the use of freezer units instead of composting.
      2. The research (contained in an enclosed presentation) also provided a comparison of the cost-effectiveness of various nutrient management BMPs – and a finding that freezing and recycling is about 90% more efficient than the average of all other ag BMPs in reducing phosphorous.
    5. Quality of life issues for growers and neighbors
      1. Local and county governments in several states have been compiling a lot of research on the various approaches for ensuring farmers and their residential neighbors can coexist peacefully.
      2. Many of the complaints have focused on the unwanted scavenger animals, including buzzards/vultures, raccoons, foxes and feral cats, as well as the smells associated with composting.
      3. The concept of utilizing sealed freezer collection units to eliminate the smells and animals associated with composting is being considered by some government agencies as an alternative to instituting deeper and deeper setbacks from property lines, which make farming operations more difficult and costly.

Future Plans

We see more work on three fronts:

  • First, we’ll continue to do monitoring and testing locally so that we may add another year or two of data to the time frames utilized initially.
  • Second, we are actively working to develop new more profitable uses for the deadstock (alternatives to rendering) that could one day further reduce the cost of mortality management for the grower.
  • Lastly, as two of the biggest advantages of this practice – biosecurity and nutrient management – garner more attention nationwide, our hope would be to see more thorough university-level research into each of the otherwise disparate topics that we were forced to cobble together to develop a broad, initial understanding of this BMP.

Corresponding author (name, title, affiliation)

Victor Clark, Co-Founder & Vice President, Legal and Government Affairs, Farm Freezers LLC and Greener Solutions LLC

Corresponding author email address

victor@farmfreezers.com

Other Authors

Terry Baker, Co-Founder & President, Farm Freezers LLC and Greener Solutions LLC

Additional Information

https://rendermagazine.com/wp-content/uploads/2019/07/Render_Oct16.pdf

Farm Freezer Biosecurity Benefits

One Night in a Composting Shed

www.farmfreezers.com

Transmission Pathways

Avian flu conditions still evolving (editorial)

USDA NRCS Conservation fact sheet Poultry Freezers

Nature.com When fur and feather occur together: interclass transmission of avian influenza A virus from mammals to birds through common resources

How Does It Work? (on-farm freezing)

Influenza infections in wild raccoons (CDC)

Collection Shed Unit specifications

Collection Unit specifications

Freezing vs Composting for Biosecurity (Render magazine)

Manure and spent litter management: HPAI biosecurity (Iowa State University)

Acknowledgements

Bud Malone, retired University of Delaware Extension poultry specialist and owner of Malone Poultry Consulting

Bill Brown, University of Delaware Extension poultry specialist, poultry grower and Delmarva Poultry Industry board member

Delaware Department of Agriculture

Delaware Nutrient Management Commission

Delaware Office of the Natural Resources Conservation Service

Maryland Office of the Natural Resources Conservation Service

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. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

PEDV Survivability in Swine Mortality Compost Piles


*Purpose

PEDv has caused significant losses in the Nebraska pork industry and mortality can approach 100%. Disposal of these carcasses is a challenge as they serve as a source of tremendous amounts of infectious virus. Current alternative methods of disposal include rendering, incineration and burial. Rendering trucks may serve as a farm-to-farm vector. Incineration is not feasible for the significant number of mortalities and burial may enable long-term survival of virus in soil and may cause re-infection after disease elimination. Therefore, composting may serve as an ideal solution for disposal and mortalities this would provide a biosecure, safe, and cost-effective method to mitigate on-farm sources of virus. The overall objective of this study was to determine the efficacy of composting as a mortality disposal method following death loss from the porcine epidemic diarrhea virus (PEDv). Validation of time-temperature combinations for PEDv inactivation in mortality compost piles was the primary intended outcome of this project.

What did we do?

PEDv virus challenge protocol modeled one that has shown previous success using weanling pigs (Hesse et al., 2013). Twenty-seven animals (approximately 21-day-old weaned piglets) were sourced from a high-health commercial source that had no history of PEDv and with dams that tested negative for the presence of PEDv-specific antibodies and were negative for fecal virus shedding as determined by PCR. Experimental groups were housed in pens and maintained at appropriate temperature and in accordance with national animal care space requirements. Pigs were given five days of acclimation and maintained on commercial nursery pig diets. Following acclimation, each pig was inoculated orally with 5 mL of virus inoculum (NE 9282) supplemented with gentamicin that had been diluted to a real time PCR assay cycle threshold (Ct) 22. Inocula (feces/intestinal contents) from a natural outbreak of PEDv were used. Pigs were evaluated twice daily for evidence of infection: temperature, pulse, respiration, dehydration, and diarrhea. Fecal samples were collected daily for evaluation of fecal shedding of PEDv. When significant clinical signs of enteric disease were present or pigs became sufficiently ill that the attending veterinarian determined euthanasia was appropriate, animals were humanely euthanized and samples taken for necropsy.

Following necropsy, carcasses from infected and euthanized pigs were composted inside biosecure rooms in the Veterinary and Biomedical Sciences Research Facility at the University of Nebraska – Lincoln. Three compost piles were constructed using commercial sawdust and wood shavings at a target moisture content of 50% w.b. For each pile, an insulated platform with internal dimensions of 121.92 cm (W) x 152.4 cm (L) (48 in x 60 in) was used to contain piles. Platforms were constructed of an outer layer of plywood and an inner layer of PolyBoard sheeting with foam board insulation in between to simulate the linear continuation of the pile and the insulative properties of a compacted soil base. Compost piles were constructed by placing a layer of wood shavings on each base to a depth of 60 cm (24 in), followed by placement of five carcasses in a single layer in the center of the pile followed by a 15 cm (6 in) layer of pile material and a second layer of four carcasses in a single layer. Additional sawdust was placed over and around the carcasses to achieve 60 cm of coverage on the top of the pile. Rooms were maintained at approximately 21°C (70°F) and 25% RH throughout the duration of the project.

Temperature was monitored at ten locations within each pile using Apresys in-transit digital temperature recorders (Apresys, Inc., Duluth, GA) beginning at establishment of the piles and continuing at a 20-min sampling frequency (duration of primary compost cycle not established at time of proceedings submission). Temperature within each pile was also monitored manually using a thermometer at 0, 24, 48, 96 h, and 168 h, and then weekly for the duration of the compost cycle to confirm success of the heating process.

Following completion of the primary compost cycle, temperature loggers will be recovered and each pile will be mixed, sampled for analysis of survivability of PEDv at five locations, moisture will be added, and piles will be re-established for a secondary composting cycle with temperature loggers placed as previously described. At the completion of the secondary composting cycle, piles will again be sampled for analysis of survivability of PEDv (5 samples per pile) and temperature loggers will be recovered.

PEDv survivability will be determined via two independent assay methods. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a rapid and sensitive method that will be used to quantify the amount of virus RNA genome in the samples. The Nebraska Veterinary Diagnostic Center currently has a validated RT-qPCR test to assay for the presence of PEDv in manure sample matrices. To validate results from the RT-qPCR in laboratory assays, sawdust simulated compost matrix will be spiked with known concentrations of PEDv target RNA and compared to known standards to ensure no inhibition is present and that proper extraction methods are being used. An alternative method using virus isolation will also be conducted to determine whether viable virus is present in flasks at a smaller subset of time points. To do this, Vero cell monolayers will be infected with filter sterilized aliquots of compost exudate, blindly passaged once after seven days, and examined for virus p resence using IFA with a PED specific monoclonal antibody. At specific time points, RT-qPCR Ct values and Virus Isolation will be run in parallel to ensure sensitivity of testing and to evaluate correlation of the testing modalities under the simulated testing conditions and matrices. If these testing methods show agreement, and/or no virus is isolated, RT-qPCR testing will be utilized to facilitate rapid and consistent assessment of virus persistence during the majority of experimental time points.

What have we learned?

Biosecurity is essential to controlling the spread of PEDv and any facility that is currently positive for PEDv should work diligently to prevent contamination of neighboring facilities. Vehicle transport has been shown as a high-risk activity that may facilitate spread of PEDv (Lowe 2014) and mortalities that are positive for PEDv may be rejected by renderers to protect them from liability for transmitting the disease. Burial of mortalities can be detrimental to water quality (Bartelt-Hunt et al., 2013) and it is unknown how long the PEDv can remain active in the cool, dark, moist environment that accompanies land burial of carcasses, but extrapolation of available data suggests virus may persist for months. Therefore, we believe composting is likely to provide an effective, biosecure, economically viable and environmentally compatible option for disposal of PEDv mortalities. This research will validate the effectiveness of composting through controlled mortality composting trials subsequent to experimental infections. With the completion of this research, our expectation is that we will know what operating parameters are required to ensure inactivation of PEDv during composting of PEDv mortalities.

Future Plans

Using the information generated from this research, we will deliver extension programming and outreach materials to swine producers, veterinarians, and stakeholders within and beyond Nebraska to promote biosecure disposal of PEDv-infected mortalities.

Authors

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

J. Dustin Loy, Assistant Professor, 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 and construction of mortality composting platforms.

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.

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.