A team of engineers and scientists, working on behalf of Swine Innovation Porc, is preparing to move into phase three of an initiative to adapt hydrovac technology to speed up and reduce the cost of washing and disinfecting swine transport trailers.
Dr. Terry Fonstad, a professor in the College of Engineering at the University of Saskatchewan, explains swine transportation has been identified as the primary risk for transferring disease-causing pathogens.
Prairie Swine Centre is involved in doing a trailer inventory.
They went out and looked at all the trailers that are being used and then looked into both animal welfare and cleanability aspects of those trailers," Dr. Fonstad says. "PAMI is developing with us a cleaning system based on a concept of using vacuum and pressure washers."
"VIDO is working on the side of pathogen destruction and giving us the engineering parameters that we need to destroy pathogens and verification of that."
"Then, on the engineering side at the University, we're looking at measuring those parameters in the trailers to verify that we're meeting the conditions that'll destroy the pathogens," he says. "I think this is a bit unique for research in that it's industry led, industry driven."
"One thing that we did made sure that we put in is an advisory team that's everywhere from producers to veterinarians to people that actually wash the trucks and we get together every six months and have them actually guide the research," Dr. Fonstad adds. "I think that's been part of the success, is having that advisory team that's made up of that diverse group of people."
Dr Fonstad says a less labour-intensive prototype hydrovac system, which requires less water that cleans the trailers to a level that facilitates effective disinfection and pathogen deactivation using heat has been developed.
He says the next step is to automate or semi-automate the system.
The CVO has activated Manitoba Agriculture's Emergency Operation Centre to assist the affected producer and conduct a full disease investigation. Control measures were implemented immediately, and a plan has been developed for restricted site access, barn cleanup and animal care. Producers within a 5-km radius of the infected site have been alerted, and are monitoring their herds and collecting samples for testing. All swine veterinarians with producer clients in the region have been notified of the site's location so that those producers are aware of the disease potential.
Sharing of the site location information was made possible by the affected producer voluntarily providing permission to his herd veterinarian to share the information at his discretion with Manitoba Pork and other swine veterinarians through signing this Sharing of Information Waiver. Providing this permission through the waiver allows the CVO and Manitoba Pork to assist the producer in a more comprehensive and timely manner, while concurrently protecting the broader pork industry. Manitoba Pork urges all producers to sign the waiver with their veterinarian – and encourages all veterinarians to ask their clients to sign it and keep it on file – ahead of a disease outbreak.
With a new case of PED in Manitoba, producers should take this opportunity to review and further strengthen their biosecurity practices, paying particular attention to the following:
- Ensure that the trailers you allow on your farm have been thoroughly washed, disinfected and dried.
- Exercise extreme vigilance with trailers coming back from assembly yards (known hotbeds for all swine diseases) and other major collection points.
- Ensure that people coming onto your site follow strict biosecurity guidelines, with only essential service people being allowed into the yard and preferably parking outside of it if possible.
- For trailers returning from the U.S., request that a second wash and a complete dry be done in Canada at a trusted facility.
As part of research being conducted on behalf of Swine Innovation Porc, scientists with the University of Saskatchewan, the Prairie Swine Centre, the Prairie Agricultural Machinery Institute and VIDO-InterVac are working to automate the cleaning of swine transport vehicles to speed up the process and cut the cost.
VIDO-InterVac is responsible for identifying approaches to inactivate the key pathogens responsible for the transmission of disease.
Dr Volker Gerdts, the associate director of research with VIDO-InterVac, said in this project scientists focused on temperatures and the amount of time at those temperatures needed to inactivate 12 pathogens, six bacteria and six viruses, considered important to the swine industry.
"Viruses in general are a little bit more difficult to inactivate because they are inside the cell but we also had a few bacteria, Streptococcus suis for example, which is also relatively resistant to heat," Dr. Gerdts said.
"If you were able to use a very high temperature, like 80 degrees, all of these pathogens will be destroyed within a very short period of time," he said. "Going lower, like at 60 or 65 degrees Celsius, then it would take much longer so it's really a combination of temperature and time.
"I can't really give you all of those but, if you were to go with a high temperature, like 80 degrees for example, that would be sufficient to kill most pathogens within minutes," he added. "If you were going to go with 70 or 65 degrees then you're probably looking more at 15 minutes or something like that."
Dr Gerdts noted the industry is using this approach already.
He said after cleaning, washing and disinfecting, they're baking the trailers but the various units are using slightly different temperatures and slightly different schedules.
June 3, 2016, Winnipeg, Man – On June 2, 2016, Manitoba’s Chief Veterinary Office (CVO) confirmed that a second case of porcine epidemic diarrhea (PED) has been found in a finisher barn in southeastern Manitoba, in addition to the one found in a batch-farrow sow barn a week ago.
The producer is fully cooperating with the CVO and has implemented control measures on the site. Epidemiological investigation is ongoing. Direct and indirect contacts and farms within five kilometers of the site are being contacted.
June 2, 2016, Winniepg, Man – On May 26, Manitoba’s Chief Veterinary Office (CVO) received positive test results for PEDv from a Manitoba batch-farrow sow barn.
The CVO has consulted with the producer’s private veterinarian and has activated Manitoba Agriculture’s Emergency Operation Centre. Control measures were implemented immediately, and a plan has been developed for restricted site access, barn clean-up and animal care.
Producers within a five-kilometer radius of the infected site have been alerted, and are monitoring their herds and collecting samples for testing.
Beginning in the spring of 2013, a deadly virus spread quickly throughout the swine industry. Porcine Epidemic Diarrhea virus (PEDv) has been reported in more than 35 states and is estimated to have an annual economic impact of up to $1.8 billion. Research recently conducted by faculty at the University of Nebraska – Lincoln (UNL) is giving swine producers and veterinarians potential methods to manage and prevent the spread of PEDv.
PEDv is spread among pigs through the fecal to oral route. It causes severe diarrhea, vomiting and dehydration, typically less than one day following exposure. While older pigs will experience performance losses once infected with PEDv, the virus carries a nearly 100 percent mortality rate in pre-weaned piglets. The virus is highly virulent, which makes controlling its spread within and among swine operations particularly challenging. Veterinarians have speculated that a thimble-full of PEDv could effectively infect all of the state of Iowa’s nearly 20 million pigs, which is roughly one-third of the United States pig population.
“PEDv has a similar effect on older pigs as the stomach flu does on humans; they decrease feed intake, lose weight and are not productive,” says Amy Millmier Schmidt, assistant professor and livestock bioenvironmental engineer in the department of biological systems engineering at the University of Nebraska. “This loss of productivity equates to an economic loss for the industry as it takes longer for the animals to reach market weight.”
The National Pork Board and Nebraska Pork Producers Association are funding the research of Schmidt and a team at UNL and the U.S. Department of Agriculture’s (USDA) Agricultural Research Service. While previous research has looked at such aspects as disinfection practices for vehicles and equipment, developing a PEDv vaccine or evaluating swine feed as a source of infectious virus, this group focused their efforts on the environmental aspect of PEDv.
One area the group has been investigating is composting carcasses testing positive for PEDv. Burial is common practice with PEDv mortalities, which may be problematic because the virus thrives in cool, moist conditions. To test whether composting could eliminate the infectious virus, the researchers constructed three compost bins in which PEDv-positive pigs were composted in biosecure rooms on UNL’s East Campus. Sensors were placed inside the compost piles to monitor temperature and organic matter, and water was added to the bins, as needed, throughout two composting cycles. Testing of the compost material at the conclusion of the cycles found no evidence of PEDv.
“Properly handling and disposing of mortalities is a crucial step in reducing the risk of virus transmission,” Schmidt says. “We’re confident that composting is an effective method to dispose of on-farm mortalities and help limit the spread of PEDv when the piles are constructed and managed properly to achieve internal pile temperatures of 120 to 130 Fahrenheit.”
Schmidt and her colleagues also looked at adding lime to manure containing the PED virus to determine if a significant pH change in the manure would eliminate the infectious virus. Results revealed that treating manure with lime to raise the manure pH to 10 for at least one hour will eliminate infectious virus in the manure, though Schmidt suspects that a lower pH may be equally effective.
Testing during the past several months has revealed that this virus is extremely sensitive to pH, and researchers suspect that it may not be necessary to raise the manure pH all the way to 10 to inactivate the virus. However, they won’t be able to confirm this until additional experiments are completed.
Another area the team has been looking at is the survival of the virus in soil over the winter following fall manure application. Schmidt and her colleagues added PEDv-positive manure to tubes of soil at varying moisture contents and then stored these soil samples for 150 days in incubators where the temperature was adjusted daily to represent daily soil temperatures from November through April in southern Minnesota, northern Missouri and central Oklahoma. The team expects to share results of this project in peer-reviewed publications soon, but initial results indicate that the virus is quickly inactivated once manure is introduced into soil having a pH of 7.5 or greater.
As the quick and natural evolution of this virus progresses throughout the U.S., the positive results from this early research are encouraging. The next step for UNL researchers is to confirm their results with on-farm studies. They have received a grant from the USDA Agricultural Food and Research Initiative through the Critical Agricultural Research and Extension program to conduct a series of on-farm studies over the next three years. They will test multiple mitigative and preventative practices for PEDv to confirm the effectiveness of these biosecurity practices.
The team’s current focus is on demonstrating and promoting disease control and prevention measures on-farm and working with pork producers to create a culture of vigilant preparedness and prevention to minimize impacts of future disease outbreaks.
“All business decisions come down to economics so we want to demonstrate that the cost of investing in on-farm biosecurity practices is far less than the costs associated with lost productivity, decontamination, and remediation of a farm following a disease outbreak,” Schmidt says.
Haley Steinkuhler is a writer with the University of Nebraska’s Institute of Agriculture and Natural Resources media team.
As everyone who farms swine in North America knows, porcine epidemic diarrhea virus (PEDv) is a very serious issue. More than eight million pigs have died of it since early 2013, and several Canadian swine farms were identified as PEDv-positive with recurrent infections.
Eradication of PEDv from farms where it’s present is a tough goal to achieve, and one of the most important considerations is how infected manure is handled and managed. In Manitoba, swine farms generally store their manure in earthen manure storages (EMSs; sometimes referred to as lagoons). These outdoor manure storages are obviously colder than under-barn pits and, contrary to what one might think, PEDv does well in them because it likes colder temperatures.
But how long does the virus survive in EMS-stored manure, and under what conditions?
A study to find out was first initiated in 2014 by the Manitoba Livestock Manure Management Initiative (MLMMI), headed by Ehsan Khafipour, assistant professor of gastrointestinal microbiology in the departments of animal science and medical microbiology at the University of Manitoba.
Finding out how long the virus can survive – and what affects its ability to infect – is critical for manure management.
“Most pork producers in Manitoba apply their own manure by contracting it out every year,” explains Mark Fynn, manager of quality assurance and animal care programs at the Manitoba Pork Council (which provides funding for MLMMI research). “These applicators use machinery that goes to numerous swine farms in a season and has the potential for carrying viruses between farms, especially since it is so hard to get the machinery immaculately clean.”
Fynn says that since the risk of PED virus transmission by manure spreading has been unknown, farmers were not willing to take the chance of having manure application equipment used at PEDv-contaminated sites being used at their own farms.
“We needed to be able to quantify the risk that lagoon-stored manure posed to the industry,” he says. “And answer the question of whether the virus is still viable, and therefore still poses a threat, several months after an outbreak.”
The study aims were to monitor survivability and infectivity of PEDv in infected EMSs, and to test in the lab how different temperatures and incubation periods affect PEDv. Two separate infected EMSs were sampled in the fall of 2014 with a second round of sampling in late spring 2015.
Sampling was carefully done to make sure PEDv didn’t spread from the research activity sites.
“We had to assume that the lagoon was highly infected and everything that was on the site – equipment and personnel – would also be infected,” says Harvey Chorney, vice-president of Portage operations at the Prairie Agricultural Machinery Institute (PAMI), a partner in the research. “We brought in protocols which included a change tent with sides that separated clean street clothes and
assumed-to-be-contaminated ‘site’ clothes.”
Only manure samples – stored in double-layer containers – were removed from the sites by personnel wearing clean clothes and boots. Vehicles that carried the samples were parked at the road and washed after each sampling. The samples were transferred to another vehicle before being taken to the University of Manitoba lab for analysis.
“Upon completion of the sampling, all waste and equipment [that] could not be sterilized was burnt on site,” Chorney adds. “Larger equipment was exposed for a period of time to heat to kill any possible PEDv that might be present. The maintenance of discipline was critical in following protocol we had established. We had no spreading of the virus so we assume success.”
Lab analysis revealed that PEDv could survive and be infective for at least nine months in infected EMSs, in Manitoba’s climatic conditions. PEDv infectivity declines at pH less than 4 and greater than 9 (with 7 being neutral). The pH of the EMSs varied from 6.6 to 8.4 with the lowest pH at the bottom layer and the highest in the top layer, which is within the range for PEDv to remain infective.
“In general, PEDv favors neutral pH but can tolerate a wide range between pH 5 and 9,” Khafipour notes. “However, temperature is a factor. PEDv is active in the pH range between 5 and 9 at 4 Celsius for example, but the range narrows down with increased temperature to between 6 and 8 at 37 Celsius. However, regardless of temperature, the viruses completely lost the ability to replicate at pH less than 4 and over 9.”
It was also noted that the virus population in both EMSs increased approximately five months after infected manure was placed into them.
“This suggests that PEDv may replicate in a EMS by using another host besides swine,” Khafipour says. “In both sites, the entrance pipes to the EMSs were sealed before sampling started, so there was no inflow of fresh manure, wash water or disinfectants during the study. Under these conditions, we expected that the virus population would either stay stable or decline over time.”
However, in EMS #1, the viral load significantly increased after the third week of sampling in all three layers, and it significantly increased in the early spring in EMS #2. This could not have been due to evaporation of water (which would increase the concentration of virus per ml), but can only be because the PEDv is replicating in the EMS outside of its typical host (swine).
It’s already known that PEDv can replicate in mammal cells other than swine, but Khafipour says in this EMS scenario, the alternative hosts are likely single-celled protozoa or amoeba.
“EMS naturally inhabit some amoeba and protozoa, but we’d need further research to investigate this aspect of PEDv survivability,” he explains. “What we are currently doing is looking at how the PEDv may have evolved in the samples collected in fall of 2014 to the early summer of 2015. Although PEDv might be able to replicate within an EMS, its ability to infect declines over time. This might be because generation after generation of the virus within the alternative host is pressuring it to evolve in ways that lower its ability to infect its previous host – swine.”
Both of the EMS sites were positive as well for porcine delta coronavirus (PDcoV). Khafipour found that PDcoV survives in EMS over a Manitoba winter, but he didn’t test its infectivity.
Manure management recommendations
Once spring arrives, there are several important guidelines manure managers and applicators should heed in spreading PEDv-positive manure that’s been stored all winter long.
“PEDv is more sensitive to +20 Celsius temperatures, which over time, can significantly reduce its population, so the longer you can let it sit into summer, the better,” says MLMMI executive director John Carney. “The optimal time to spread PEDv-positive manure is likely on warm, dry days. Sunlight [UV radiation] and warmer temperatures may reduce the ability of the virus to infect and prolonged agitation of an infected EMS may aid in exposing the EMS’s contents to these conditions.”
It is also recommended that producers hold back and treat infected manure in under-barn pits before pumping manure into EMSs where it could potentially flourish.
“When pumping manure,” Carney adds, “applicators should follow a sequence, beginning with PEDv-negative sites, followed by sites with the longest time since an outbreak to sites where PEDv was most recently reported.”
For more information on the study, visit manure.mb.ca/projects/viewproject.php?id=97 or journal.frontiersin.org/article/10.3389/fmicb.2016.00265/full.
April 26, 2016, Sioux Falls, SD – While often considered a condition of dairy cows, Johne's Disease has increasingly been identified as a concern for beef producers, and paying attention to manure exposure is a crucial component in controlling it, said Russ Daly, professor, South Dakota State University Extension veterinarian and state public health veterinarian.
Johne's Disease primarily affects the intestine, so manure is the source of bacteria that infects healthy cattle, Daly said. READ MORE
March 30, 2016, Winnipeg, Man – An assistant professor with the University of Manitoba says more effective disinfectants, capable of killing the virus responsible for Porcine Epidemic Diarrhea within stored manure, need to be developed.
A research study conducted by the University of Manitoba and the Prairie Agricultural Machinery Institute has shown the virus responsible for Porcine Epidemic Diarrhea can survive for long periods of time in earthen manure storages but the infectivity of the virus will vary according depth in the lagoon and environmental conditions.
Scientists analyzed manure samples collected at various depths of the earthen manure storage of two PED infected farms.
Dr. Ehsan Khafipour, an assistant professor with the University of Manitoba, says even nine months after an initial outbreak the virus remains present in the infected manure.
“If the virus is present in the manure and our data shows the number of virus is even increasing without any new entrants of infected manure into this EMS so the questions is, even if the virus is finding a new host and is able to replicate but the infectivity is not as much, how do we have to handle this manure,” says Dr. Khafipour.
“What should be our approach in handling the manure? As part of the research, we looked at some of the chlorination methodology for example to see how we can disinfect the virus and our results weren't that promising.”
“Hopefully the companies that are working on new disinfectants that might be more effective against PEDv will take up the research and do more research on it,” he adds.
Dr. Khafipour says the study shows producers need to remain cautious when dealing with stored manure following a PED outbreak.
December 14, 2015 – Animal-nutritionist John Goihl knows Minnesota farmers who feed the remains of dead baby pigs to hogs used for breeding in attempts to ward off infections of a deadly virus in offspring.
In Oklahoma, farm workers are mixing manure from swine sick with the disease, known as Porcine Epidemic Diarrhea virus (PEDv), into the food of healthy animals to build their immunity.
In Kansas, farmers are spraying a mixture of hog manure containing the virus and water on the noses of pigs to create a "natural vaccine." READ MORE
A commercial turkey operation in western Ohio. Photo by Ken Chamberlain
November 24, 2015, Wooster, OH — One of the main challenges posed by the avian flu outbreak that has impacted the U.S. poultry industry in the past year is how to safely and effectively dispose of potentially hundreds of thousands of birds killed as a result of infection and eradication efforts.
“The U.S. strategy is to quickly identify the infected premises, depopulate, properly dispose of carcasses and manure, clean and disinfect the premises, and have 21 days of down time after cleaning before re-population can take place,” said Mohamed El-Gazzar, Ohio State University Extension’s poultry veterinarian. “As you might imagine, the logistics of depopulation and disposal are very challenging, particularly with the large-scale layer complexes, some of which have a capacity of more than 5 million birds.”
In 2015, this strategy has resulted in the culling of 7.5 million turkeys and 42.1 million egg-layer and pullet chickens, according to the U.S. Department of Agriculture.
While the avian flu outbreak has not impacted Ohio poultry, experts with the College of Food, Agricultural, and Environmental Sciences at The Ohio State University have been helping poultry producers learn about the disease, boost biosecurity measures on the farm, and prepare to minimize the flu’s impact if it were to reach the state.
To address the challenge of safe disposal in the event of an outbreak, El-Gazzar sought the collaboration of Fred Michel, a biosystems engineer with the Ohio Agricultural Research and Development Center OSU Extension composting specialist. OARDC and OSU Extension are the research and outreach arms, respectively, of the college.
Michel said there are four ways to dispose of such large numbers of dead animals at a time: incineration, onsite burial, landfilling and composting.
“Incineration is difficult and expensive and there is not sufficient capacity,” he said. “Onsite burial is a possibility, but the areas where many Ohio poultry farms are located (Darke and Mercer counties) have high water tables and there may be issues with ground water contamination.
“Landfilling can be effective, but it increases the risk of spreading the disease to other areas during transportation. So onsite composting seems to be the best option, as it would prevent contamination of water, effectively destroy the pathogen and eliminate the risk of spreading the disease to other farms.”
However, Michel said, there were some issues that needed to be addressed when he started considering a plan for on-farm composting of large numbers of birds.
“Fact sheets on composting birds currently available around the country only address the process of composting a few birds at a time, not the large number involved in a catastrophic event,” he said. “So we had to come up with the right formula and method to make this type of composting work.”
Additionally, composting hundreds of thousands of birds at commercial farms would require a large amount of carbon-rich amendment material, such as sawdust, wood chips, yard trimmings or straw.
“For composting to be done right, you need a carbon-rich, dry feedstock,” Michel said. “Birds are low in carbon and too wet. So an amendment material is needed to compost them.”
For egg-laying operations, Michel designed a slab composting method that includes a one to two foot base of wood chips or mulch, followed by layers of chickens, finished compost and mulch. The top and sides of the slab are covered with amendment material, which insulates the slab and helps prevent leakage and odors.
A pile measuring seven feet high, 100 feet long and 100 feet wide — approximately one-fourth of an acre — would be needed to compost 150,000 birds at the same time, Michel said. Such a pile would require approximately 2,600 cubic yards of amendment material.
“The pile is left without mixing for at least two weeks,” Michel said. “The temperature generated by the composting process will kill the virus. After this, the pile could be left to further degrade or be turned.”
For broilers and turkeys, the method of composting would vary because of different production practices.
“You could just use the bedding material that’s already in the broiler or turkey houses and mix the dead birds in. Then you make a windrow (a long, low heap of composted material) inside the facility,” Michel said.
In addition to developing a spreadsheet for the design of large-scale poultry composting based on the slab method, Michel created an online map that includes the location and contact information for businesses that sell amendment materials. All of this information is available on the Ohio Composting and Manure Management (OCAMM) program’s website: www.oardc.ohio-state.edu/ocamm/.
Besides being a safe and environmentally friendly way for producers to dispose of dead birds in the event of an avian flu outbreak, composting would also generate a good fertilizer product that the farms could use for their crops, Michel said.
Since November 2014, the outbreak of highly pathogenic avian influenza H5 has resulted in the death of some 50 million birds from commercial and backyard flocks in 21 states, according to the U.S. Department of Agriculture.
Originally spread by wild waterfowl, the virus has impacted turkey and chicken producers in the West and Midwest. Heavy losses to egg farms in Iowa — the nation’s No. 1 producer of eggs until the current outbreak decimated production there — have sent egg prices soaring across the United States, more than doubling in some parts of the country. The outbreak has also led to a spike in the price of turkey products.
It’s been almost six months since the last new case of highly pathogenic avian influenza (HPAI) was reported in North America (knock on wood). And now that the dust and feathers have settled from the destructive outbreak – more than 49 million chickens and turkeys destroyed plus almost $1 billion in tax payer costs – the poultry industry and government officials are taking time to gather and discuss lessons learned from the “worst animal disease in U.S. history.” And prepare for something even more catastrophic.
In mid-September, the U.S. Department of Agriculture released its Fall 2015 HPAI Preparedness and Response Plan (available at aphis.usda.gov). This document builds from the department’s experiences during the spring 2015 outbreak and assumes a worst-case scenario involving 500 or more commercial operations infected across a wide geographical area.
“APHIS (Animal and Plant Health Inspection Service) focused considerable effort in the area of depopulation and disposal during our fall planning activities,” the document states. “The size of the [spring 2015] outbreak clearly outstripped the capacity to depopulate flocks and dispose of carcasses. Additionally, a number of hurdles further delayed our ability to quickly use landfills and incinerators for carcass disposal,
such as concerns over liability, environmental impacts, and public acceptance.”
No one understands those hurdles better than Mark Van Oort, complex manager for Center Fresh Egg Farm – an Iowa-based egg laying facility. He shared his HPAI experience during the Fifth International Symposium on Managing Animal Mortalities, Products, By-Products and Associated Health Risks, held in Lancaster, Pa., this past fall. During the spring outbreak, Van Oort was given the unenviable task of guiding Center Fresh through large-scale euthanasia of more than seven million laying hens plus disposal of carcasses, manure and feed. During his presentation, he described, in detail, his frustration discovering what he could legally do to dispose of the operation’s growing pile of dead birds and manure. Eventually, he was given the go ahead to compost the carcasses.
As a result of Van Oort’s and other stakeholders’ experiences, APHIS reviewed federal and state regulations pertaining to carcass disposal in order to identify potential challenges and solutions to overcome them.
And not just the USDA is looking at this issue. The U.S. Poultry and Egg Association recently circulated a request for research proposals on how best to dispose of poultry carcasses as rapidly as possible. Pre-proposals were due in by early November. It should be interesting to see what technologies make it through for further investigation.
U.S. Poultry also plans on holding a one-day “Lessons Learned” program discussing HPAI on Jan. 28, 2016, during the International Production and Processing Expo in Atlanta, Ga. Visit ippexpo.org for a full schedule.
For those interested in learning more about the Fifth International Symposium on Managing Animal Mortalities, Products, By-Products and Associated Health Risks, proceedings from the event were recently posted online. Visit animalmortmgmt.org to access them.
The second phase of the trailer disinfection research project is well underway, which involves testing a vacuum system combined with high-pressure washing. Photo by Contributed photo
The presence of Porcine Epidemic Diarrhea Virus (PEDv), which appeared in the U.S. in April 2013 and in Canada in January 2014, presents tough challenges for manure managers.
In a guide called Biosecure Manure Pumping Protocols for PEDv Control, published by the U.S. National Pork Board and partners, it states that “PED virus transfers via feces and survives in manure for extended periods of time. Any object that becomes contaminated with pig manure can be a source of infection.”
One of those objects is, of course, swine transport trailers. That’s why a group of researchers at the University of Saskatchewan (U of S) in Saskatoon are evaluating a combination of methods to ensure complete disinfection of trailers in order to reduce the risk of disease exposure. There is a wide range of pathogens that can be spread from organic material left in a transport vehicle, including PEDV, PRRSV, PCV, S. suis, brachyspira and many more. The initiative is part of a multiphase project being conducted on behalf of Swine Innovation Porc.
“Industry came along and said that they are spending a significant amount of time and money to clean their trailers, but that they’re not sure if the trailers are clean enough,” says lead investigator Dr. Terry Fonstad, with the college of engineering at the U of S. “There are nooks and crannies that exist, and it’s hard to know if they are completely disinfected. So, the goal of our project is to develop an easier and more efficient process to disinfect trucks and save the producers some real money.”
While trucking companies do their best to wash out trailers extremely well, Fonstad notes that solid data is needed on what works best.
“We’ve got larger companies with top-notch systems to clean trailers and they let them sit to completely dry and several days before the next use,” he explains. “But it’s hard for smaller haulers to make money with a trailer that may take six to eight hours to clean and then is out of use while it totally dries. If we have an efficient method that kills all pathogens and reduces the cleaning time, everyone will benefit. Even supposedly clean trucks at the border going either way could be treated again as a reassurance.”
Fonstad says effective cleaning of a trailer means ensuring that – whatever means are being used – there is enough contact time between the disinfectant and the pathogen. He notes that if there is a piece of manure stuck somewhere, the pathogen is protected in that material, and it doesn’t matter what disinfectant you use if there isn’t adequate contact between the disinfectant and pathogen. “The larger the clump, the harder it is to get to the middle of it, to heat it or get rid of it,” he explains. “You can even use just hot dry heat, but if there is thicker crust or pieces of material, you have to have longer heating time. So, we first need to know exactly what is required to completely destroy the viruses and bacteria, and then develop a method that works when you test it on a truck with real world conditions.”
Phase 1, a look at current technologies, is now complete. “Dr. Volker Gerdts and colleagues at the Prairie Swine Center completed a literature review and found all microbes may be destroyed when exposed to 70°C for at least 10 minutes,” Fonstad says. “Of course, if we could heat the whole trailer to that temperature for that long, we could safely say that trailers were clean. But we need to determine the feasibility of heating livestock trailers to these temperatures, or we needed to come up with something that would achieve the same results.”
Phase 2 of the project is well underway, which involves testing a vacuum system combined with high-pressure washing. Researchers at the Prairie Agricultural Machinery Institute (PAMI) in Humdoldt, Sask., are part of the team and tested various vacuum systems with different-sized hose ends, and the results were very good. The team ended up designing a dual head that looks like a carpet-cleaning vacuum head combined with a high-pressure water system outlet.
Fonstad notes that the head provides several benefits, including the fact that it uses significantly less water than a standard high-pressure water hose.
“Because of the vacuum aspect, it also works in such a way that all the manure and water can be contained within the system,” he notes. “This is obviously cleaner for the surroundings and it’s also faster than cleaning a trailer by just hosing it out.”
Right now, the system is manual, but the team plans to develop a set of tools that could automate the process to some extent, with the ultimate goal of a fully-automated system.
“We also need to look at the impact of the system on the trailer parts,” Fonstad explains. “We can’t have a system that impacts airlines, and whether heating a trailer to that temperature and then putting it out in the cold will cause undue damage.
“The system can then be taken and marketed by a commercial partner, eventually,” he adds. “We suspect it will have other applications outside of swine transport.”
When asked if more inspection should be done on transport trailers to make sure pieces of metal haven’t become bent and so on (thereby creating new places where manure could get stuck), Fonstad answers: Yes.
“It would be a good master’s graduate student project, to look at this inspection aspect and to look at trailer design. There are probably some opportunities to add a panel or welding a piece here or there to prevent manure from getting into nooks and crannies and corners.”
However, Fonstad sees a need for a better, more permanent long-term solution in the future.
“Yes, we can likely do all kinds of things with existing trailers to prevent opportunities for pathogens to hide, but ultimately down the road, we need to look at an improved transport system,” he says. “It could be improved trailers or crates or something else, dedicated swine transport containers that can be put through automated washing machines.”
Manure trailer ventilation
Dr. Bernardo Predicala has been working to design, develop, and evaluate an air filtration system for swine transport trailers to better protect pigs from airborne pathogens. Predicala manages the Engineering Research Program at the Prairie Swine Centre in Saskatoon, Sask. and is also an adjunct professor in the department of chemical and biological engineering at the University of Saskatchewan.
The final design (composed of an axial fan, pre-filter combined with high-efficiency filter, air inlets, and air exhaust vents with shutter) was installed on a commercial swine gooseneck transport trailer, and tested for its ability to maintaining a pathogen-free environment.
Predicala says fabric bag filters performed better than the MERV 16 filters, but are more expensive. In his view, “there would be situations wherein MERV 16 filters are sufficient (e.g. short-haul trips, low risk of airborne infection along the route, relatively low potential losses), but for situations where higher risk is involved and the loss potential is large (e.g., transporting high-value breeding stock through routes with high pig density), fabric bag filters would be more suitable.”
With regard to trailer filtration systems in general, Predicala recommends the installation of an environmental controller to better regulate the temperature inside the trailer (for animal comfort), and also using a temperature-monitoring/carbon dioxide detection system with an alarm detectable in the truck cab.
“You also want to avoid high fan static pressure,” Predicala adds. “It leads to more work by the fan motor to deliver the needed airflow, and consequently uses more power.”
One way to reduce fan static pressure is to provide larger openings for the air to flow through such as the inlet, the filter area as well as the exhaust vents.
- Terry Fonstad, Ph.D, P.Eng. – (Team Lead) - College of Engineering, University of Saskatchewan
- Volker Gerdts, Ph.D. – (Pathogen Lead) - Associate Director (Research), Chief Science Officer, VIDO-InterVac, University of Saskatchewan
- Hubert Landry, Ph.D., P.Eng – (Machinery Lead) - Project Manager – Agricultural Services, Prairie Agricultural Machinery Institute
- Denise Beaulieu, Ph.D. – (Pathogen Reviewer) - Research Scientist – Nutrition, Prairie Swine Center, University of Saskatchewan
- Neil Ketilson, BSA – (Industry Lead) - General Manager, SaskPork
November 2, 2015, Winnipeg, Man – Research conducted on behalf of the Manitoba Livestock Manure Management Initative has shown the virus responsible for PED is capable of surviving over Manitoba winters in earthen manure storages.
To assess the survivability and infectivity of the virus responsible for Porcine Epidemic Diarrhea, engineers with the Prairie Agricultural Machinery Institute collected manure samples from various depths of the earthen manure storages on three PED infected Manitoba farms and researchers with the Department of Animal Science at the University of Manitoba then analyzed those samples to determine how long the virus could survive under Manitoba conditions.
“We knew from some work that had been done in Minnesota by Sagar Goyal that the virus survived longer in cold conditions and that it liked wet conditions,” said Carney. “Sagar Goyal's work proved that it lived at least 28 days in cold conditions and what we found was that, unfortunately, this virus is capable of surviving over winter in Manitoba earthen manure storages, which is a concern to the industry that this bug is that hardy that even living through minus 30 winters in our province doesn't kill it so this is one tough bug.”
“The other thing is Sagar's work was done in a laboratory and you're always curious, in a real world setting on a working farm, are there differences of how things happen between that situation and a lab and so we were able to take it from a lab setting out to working farms.”
Carney said these findings suggest, when a farm is PED positive, the first line of defense is to kill the virus in the pits under the barn rather than releasing it into the earthen manure storage.
October 5, 2015, Tucker, GA – The US Poultry board research initiative is requesting pre-proposals on the rapid disposal of poultry carcasses following depopulation.
Mass depopulation and disposal of large caged layer facilities present daunting challenges for both euthanasia and disposal. The recent avian influenza outbreak has shown that current disposal methods may be inadequate for rapid depopulation and disposal on large farms. Innovative methods are needed for rapid, safe disposal of the carcasses and manure. Opportunities may exist to improve currently used disposal methods.
The area of focus for the research will include the development of alternative methods or improvement of existing methods to rapidly, safely dispose of large numbers of layer carcasses and manure with an emphasis on validating that the disposal method inactivates the avian influenza virus and evaluating the potential of spread of the avian influenza virus during carcass and manure disposal process.
September 1, 2015 – The recent outbreak of avian influenza, a highly contagious viral disease that has infected about 48 million birds in the United States, resulted in a significant loss to the poultry industry. The initial response by the poultry industry to prevent widespread avian influenza was to more stringently enforce the U.S. Department of Agriculture biosecurity measures defined by the USDA Animal and Plant Health Inspection Service (APHIS).
However, the continuous spread of the avian influenza made the industry wonder if the disease is airborne and transmitted through ventilation air of poultry facilities. We are looking at major air emissions — ammonia gas and dust particles — from poultry facilities and their potential effects on poultry health to explore the need of additional biosecurity measures to prevent transmission of infectious diseases among poultry in the future. READ MORE
The 1983-84 outbreak of Highly Pathogenic Avian Influenza (HPAI) resulted in euthanizing approximately 17 million chickens, turkeys and guinea fowl in Pennsylvania and Virginia before the disease was contained and eradicated.
In 2004, the U.S. Department of Agriculture (USDA) confirmed an outbreak in chickens in Texas. The disease was quickly eradicated due to coordination and cooperation between USDA and state, local, and industry leaders.
However, in 2015 chicken farmers were not as lucky. The Poultry Site reports that due to the warmer weather the spread of the HPAI has slowed, but as of mid June the total infected or destroyed has reached over 47 million birds. And the USDA says that of that number, 31.454 million were laying hens, 5.874 were pullet chickens, and turkeys at about 7.76 million.
Composting the top choice
For farmers, the death of the chickens and turkeys is just the start. Disposing of the chickens and turkeys on this kind of scale has been a monumental challenge.
Composting is the preferred method of disposal for several reasons according the U.S. Environmental Protection Agency:
- the heat generated from composting deactivates the HPAI.
- on-site composting limits the risk of groundwater and air pollution contamination
- limits the risk of potential for farm to farm disease transmission
- limits the transportation costs and tipping fees associated with off-site disposal
- creates a usable product
Most farmers are trying the compost the chickens, but in areas like heavily-hit Iowa, where farmers are dealing with millions and millions of chickens, and locals are dealing with the intense smell, the USDA and Iowa contracted with three state landfills, including one with a large incinerator to help speed up culling, bird disposal and barn clean up.
Aid from APHIS
Experts have been called out to the filed by Animal and Plant Health Inspection Service (APHIS) to help farmers develop and implement composting on their farms. Mary Schwarz, extension support specialist of Cornell Waste Management Institute, was one of many composting experts who responded.
“A call went out from APHIS to a group of people that had expertise in mortality composting asking if we were available. They said, ‘If you think that you can go for between three and eight days to a place where [outbreaks] are happening, let us know.’ A lot of people have gone out and helped in different places. And they’re still going out, trying to help where they can with this expertise.”
Challenges for farmers
Schwarz travelled to Wisconsin and then on to Iowa to assist. She says that she found the biggest challenge for U.S. farmers trying to compost the birds was locating enough carbon. This carbon material, such as woodchips, is used to absorb moisture from the decomposing fowl and provides structure (for good airflow) in the compost pile.
“With birds that are housed in buildings with large amounts of litter – like shavings and such – carbon is already there. And, bird manure mixed with litter tends to have the correct moisture content and carbon to nitrogen ratio for composting on its own without having to add more,” explains Schwarz. “When the birds start to get a little bit larger – some of the turkeys we dealt with in Wisconsin were 65 pounds – we needed to be able to secure more carbon because the amount of carbon they were bedded with wasn’t quite enough to envelope those large birds.”
Where do farmers find carbon? Some farmers have gone to municipalities that had it available. Mulch producers or any company that produces wood chips were also an option.
“In other places, like in North Dakota, they were using corn stalks and corn cobs and whatever chunky carbon source that was available,” says Schwarz.
Science of composting
For the purposes of disease control, in-house composting in preferable, because it is more biosecure. Ideally, the birds should be moved as little possible, and all litter and organic material should be composted with the birds. But whether farmers compost in-house or outside, Schwarz says mortality composting, it much like regular composting, just “backwards.”
“When you compost normally, you would make a mixture that has a carbon to nitrogen ratio of between 20 and 30:1, and has 50 percent moisture. You would put it in a pile and turn it. With mortality composting, your feedstocks are separate, so your nitrogen is the animal and your carbon is this envelope that you stick the animals in. It generally will start off with a carbon to nitrogen ratio of 50:1 because they’re separate.
“Until the animal starts to decompose within the pile, there’s going to be little mixture of nitrogen and carbon,” Schwarz adds. “As the animal starts to decompose anaerobically, the body cavity starts to open and moisture is released. And then hopefully, if you have a thick enough base, that moisture is all contained within that base of carbon.
“At that point you get aerobic decomposition where the microbes start digesting both the nitrogen and the carbon available, and heat is generated. The microbes change to the heat loving microorganisms and continue to digest. When you’re flesh waste is gone – about two weeks for small birds – you’re at that point where you can mix the pile and it starts to resemble regular composting.”
Testing your compost
Currently, temperature is the measure to see AI has been controlled. Temperature probes should be used to record temperatures. Research by the University of Delaware Extension Service found 10 to 14 days of composting without turning at a temperature up to 160 F (71 C) completely inactivated the avian influenza virus in windrows of composted mortalities.
According to an information bulletin from the Cornell Waste Management Institute, research has also found that by mixing field manure with avian influenza virus and composting, the virus lost its infectivity after 15 minutes at 56 C (133 F), 24 hours at 30 to 37 C (86 to 99 F), and two days at 15 to 20 C (59 to 68 F).
One option Schwarz says is for farms to begin composting in house and, after the first 14 days, move the material outside to finish the composting cycle.
“That allows them to start doing cleaning and disinfection in the house. It all depends on the size of the operation.”
Equipment & application
If there is a bright spot, the equipment needed to compost is normally available on the farm.
“Even with a large operation, you need a skid steer with a bucket, or a tractor with a bucket that reaches a little bit higher than a skid steer might,” says Schwarz. “As far as turning goes, you can also turn with a bucket.”
Although the compost will be disease-free after 30 days if kept at the right temperatures, Schwarz said applying it immediately to the field isn’t ideal.
“It will be high in carbon and probably rob nitrogen from the soil. If it’s allowed to compost longer, it will become a better soil amendment.”
As farms in the Midwest deal with large scale composting, states like Mississippi, Indiana, Alabama and Georgia are getting ahead of game. No one is confident that the warm weather will kill off the virus.
Georgia, the nation’s leading producer of chicken raised for meat, is one of the states that hasn’t had an AI outbreak yet but isn’t taking any chances.
“We’re better safe than sorry,” said Dr. Robert Cobb, a state veterinarian for Georgia, to Reuters. “All the research I’ve been able to find is showing that this virus could likely stick around for years.”
Schwarz says that most farms she visited in Wisconsin were fairly well prepared for an outbreak. However, she feels they could have been more prepared if they’d been told exactly what to do if it should happen.
“For this reason, the group of subject matter experts are trying to create a document that will allow at least the Department of Agriculture in each state to pass it along to their producers.”
And for those that want to be prepared, Schwarz suggests attending the Fifth International Symposium on Animal Mortality Management, held September 27 to October 1 in Lancaster, Penn. One of the pieces of the program will be a training exercise on avian influenza response.
In the meantime, APHIS is working hard to create a resource for farmers.
“At least 30 or 40 of us that are from different states that do mortality composting are working together to create a standardized national protocol.”
She says it won’t be directions everyone must follow, but information about composting (cycle times, temperatures, etc.) so farmers can be prepared and know how to inactivate the virus.
Cornell also offers others resources on their website, including links to various state’s regulations via an interactive map and a link to the U.S. mortality and butcher waste disposal laws.
June 17, 2015, Des Moines, IA – Iowa Governor Terry Branstad signed a proclamation this week that will allow poultry and egg producers in 18 counties hit by bird flu to more easily dispose of manure and dead birds from affected farms.
As the number of new cases of highly pathogenic avian influenza slows, poultry farms have turned their attention to clean up and repopulation following the worst-ever U.S. outbreak of the virus that has claimed more than 47 million birds nationwide. READ MORE
June 15, 2015, Winnipeg, Man – Researchers with VIDO-InterVac are evaluating a combination of methods to ensure 100 percent disinfection of swine transport vehicles.
As part of a multiphase initiative being conducted on behalf of Swine Innovation Porc to automate the washing and disinfection of swine transport vehicles to reduce the risk of exposure to PEDv and other pathogens, scientists with VIDO-InterVac and the Prairie Swine Centre are examining physical methods for deactivating these organisms.
Dr. Volker Gerdts, the associate director research with VIDO-InterVac, says the key factor with PEDv is that the number of viral particles required to cause disease is very low and once the pigs are sick they shed lots of virus so you need 100 percent disinfection.
“As you know a truck, there's manure on it and manure gets then hidden behind certain corners or little pieces of metal or what ever, so the key issue for this is that you are getting to all the material and you that have penetration into all the organic matter,” said Dr. Gerdts. “Manure consists of a lot of organic matter and the viruses within this cell and you have to ensure that whatever means you're using, that there is enough contact time between your disinfectant and your virus.
“So this project is looking at more effective ways of cleaning the truck and disinfecting the material, potentially contaminated material that has the virus. Our role in the project is to look at what means do you have to use to completely inactivate the virus? In other words we're looking at heat for example, we're looking at various disinfectants, at things like that to verify that the virus is completely inactivated.”
Dr. Gerdts says the goal over the next six to eight months will be to demonstrate the methods being used completely destroy the virus, then a test truck will be built to mock real world conditions.
May 5, 2015, Winnipeg, Man – The president of La Broquerie, Man., based Precision Pumping says the relatively dry spring has been a big help in minimizing the risk of spreading the virus responsible for Porcine Epidemic Diarrhea.
As a result of this year's early spring, the seasonal ban on spreading livestock manure ended 10 days earlier than normal, April 1.
Doug Redekop, the president of Precision Pumping, says, despite the early spring melt and relatively dry weather conditions, the biggest challenges faced by manure applicators so far has been ice in the lagoons and getting equipment stuck in the fields but the risk of spreading PED remains top of mind.
“There is one crew that has isolated their equipment and was anticipating pumping just PED sites and then one of the other PED positive sites, they have their own equipment and so I think the key here is that not everyone is going to be actively out there looking to pump these sites,” he said.
“We can be happy in the fact that it's been drier. PED and the spread of PED is a lot like TGE and so if you've got wet moist conditions and you have the ability to track the virus with either mud or manure or so on and so forth, wet damp conditions would certainly be your enemy so the dry conditions have certainly been a positive.”
Redekop says, with every PED case that has been identified, the pork industry has worked tirelessly to identify the source of the disease and as far as he knows there have been no incidents where manure applicators have been identified as the source of spread.
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