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Stopping Dirty Air May Stymie PRRS

Gil Patterson DVM with cyclonic air collector
<p>Minnesota swine veterinarian Gil Patterson displays a cyclonic air collector used to test air samples to test for the porcine reproductive and respiratory syndrome (PRRS) virus.&nbsp;</p>

Minnesota swine veterinarian Gil Patterson looks for three things when he walks into a hog barn: feed, water and air quality.

“You’ve got to have those things right before you can really dig into other issues. If there is a dusty, poorly ventilated environment, then it is uncomfortable for both pigs and farm employees, often leading to reduced growth and poorer-quality chores,” says the St. Peter, MN, Swine Vet Center clinician.

Stopping dirty air is an especially big challenge when dealing with hog barn dust. “Face masks are uncomfortable, and unless you are very diligent, you are probably not going to wear them,” he says.

EPI Technology

Electrostatic particle ionization (EPI) technology has been around a long time, but got the attention of the swine industry about four years ago when Baumgartner Environics of Olivia, MN, obtained a patent on the process, Patterson says, and started marketing it under the name EPI Air (

Basically, the technology works by continuously emitting a high concentration of negatively charged ions into the airspace. The ions transfer their charge to airborne particles, which are then attracted to grounded surfaces like a magnet. Clumps of dust will literally “stick” to gates, feeders or floors held in place by the ion field, Patterson explains.

There are two major components of this system in a hog barn: the transformer or power unit, and the corona lines, which are pipes suspended above the pens that extend the length of the barn. The ions are dispersed into the air from corona points, small metallic projections evenly distributed along the length of the pipe.

The original version of EPI-1.0 featured a wire suspended high at ceiling level. “It created environmental problems in the barn because dust would collect around the lights — and you want to work in a well-lit workplace,” Patterson comments.

Recently, the company released EPI-2.0. Its major advantage is the ability to change the height of the steel pipe that emits the ions. “You can come to work in the barns and press a control switch that activates a winch to elevate the pipe to ceiling level, which allows you to get into the pens and do your chores. You can then lower it back down to just above the pig level in the pen when you leave the barn,” Patterson says. The advantage of the new design is that it brings the ion field closer to pig level, providing a higher concentration of air-cleansing ions in the space the pigs are breathing.


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Additionally, there is less buildup of dust around the lights in the barn because the ion field is more focused on the pigs’ airspace, Patterson says.

“The ionization creates a field like static electricity. It will make your hair stand on end if you stand under it and produce a tingle in your arm if you place it under there. If you were to accidentally touch the corona pipe while the system is on, you will get a shock similar to that of an electric fence,” he says.

The hog barn may actually appear dirtier when you walk through it because of all of the clumps of dust that have settled on surfaces.

“What you don’t realize is that if you were in a room that didn’t have EPI Air, all of those dust particles would be in the air. With this system, the pig doesn’t have to focus as much of its energy on cleaning out its lungs and battling dust; it can concentrate on growing and not potentially stimulating the immune system,” Patterson says.

Early Research Results

Research from a Murphy-Brown hog operation in Utah looked at the impact of EPI Air on nursery pig performance. The data compared the nursery performance of more than 44,000 weaned pigs, evenly distributed between barns either with EPI (treatment) or without (control). Data were collected over five nursery turns from 2009-2010.

Using an optical particle counter, a precisely calibrated instrument that measures the amount and size of dust particles in the air, there was 40%-60% reduction in levels of both large and small dust particles. Hydrogen sulfide gas levels were also reduced by 58.6%. Average daily gains jumped by 12.2% and pig mortality was reduced by 1.2% in the rooms outfitted with EPI Air. This information was extracted from a talk at the 2012 American Association of Swine Veterinarians (AASV) annual meeting.

PRRS Research Proposal

Impressed by the data from the Murphy-Brown trial, Patterson set out to try to determine the technology’s potential role in controlling transmission of porcine reproductive and respiratory syndrome (PRRS). He developed a research proposal seeking answers to these questions:

● What effect does EPI Air have on PRRS virus?

● Can it reduce the quantity and viability of PRRS in aerosols generated by infected pigs?

● Can it reduce the amount of PRRS exhausted from the environment?

At the 2013 annual meeting of the AASV, held in San Diego, CA, Patterson’s proposal was awarded one of the 2013 Advancement in PRRS Research awards, a $25,000 research grant provided by Boehringer Ingelheim Vetmedica Inc. (BIVI). University of Minnesota graduate student Carmen Alonso, DVM, helped Patterson design the research study and also helped to collect samples and analyze the data.

“If we can show that EPI reduces the amount of virus that is exhausted from the environment, then it may have potential for helping to control regional spread. That would be a big deal for neighbors, especially in hog-dense areas,” he explains.

Hog Farm Study

The PRRS study was conducted at two sites in southern Minnesota during the summer of 2013. This report covers preliminary results of a triple-wide, 3,000-head, wean-to-finish farm in south-central Minnesota built in 2012.

The barn had three identical rooms, each with 1,000 finishing spaces. The EPI Air system was set up in two of the rooms, while the third room did not have EPI and served as control. Pigs were sourced from a PRRS-positive sow farm determined to be infected with an identical strain of the virus.

Upon entry, the barn was double-stocked to just over 6,000 head (2,000/room). Half of the pigs were moved off-site 5-6 weeks post-arrival.

The 21-day-old weaned pigs were moved into the barn on six weaning days over a 12-day period. “The main thing I did differently was I filled these rooms simultaneously instead of filling one room at a time,” Patterson says. Each wean day, those pigs were unloaded into a holding pen before being split evenly among the three rooms. This process was repeated until the rooms were filled.

“The idea behind this was to evenly distribute the ages and disease status of the pigs between the rooms. I wanted the amount of PRRS shedding in each room to be equal,” he says. Random pigs were also tagged and blood-tested on arrival, and PRRS-negative pigs were blood-tested later to see if there was any difference between the treatment and control rooms in how fast they converted positive to PRRS. Cotton ropes were also hung in each barn weekly to help determine when PRRS shedding would be at its peak.

Two weeks after the last wean day, nearly 67% of the pools of samples that were negative on wean day had turned positive, Patterson points out. And 100% of the ropes that were hung turned positive. “At this point, I knew there was a lot of PRRS moving around the barn, which was exactly where I wanted to focus my air sampling,” he says.

To test air samples for PRRS, he set up six cyclonic air collectors (two/room) to run simultaneously for 30 minutes per test period inside the barn. The same procedure was used outside the barn directly in front of the pit fans to find out how much PRRS virus was being exhausted from each room, he says. Air sampling was done four times per day for 13 days.


A total of 32% of the air samples taken in the rooms with EPI Air tested positive for PRRS, compared to 42% of the air tested in the control room (no EPI Air). A total of 57% of the air samples taken outside the treatment rooms were positive for PRRS virus, vs. 64% of the air samples taken from the control-room exhaust. Despite this encouraging trend, the results from this portion of the study were not statistically significant. 

Pigs that were initially negative for PRRS tested positive at a very similar rate between the rooms. “This suggests that the primary means of spread of the PRRS virus, once it is in a barn full of pigs, is nose to nose and less by aerosol,” Patterson says.

“There was also a 31% reduction in dust levels. After this study, I cannot say for sure that EPI reduces the amount of PRRS in the air. However, there does appear to be a trend toward reduction, which tells me that further testing is needed to find out the answer,” he says.


Although the results so far do not appear to be statistically significant, there are indications that EPI Air may lower the amount of aerosolized PRRS virus. “The potential to reduce risk may help prevent spread of disease in hog-dense areas. It may be a useful tool to help keep negative barns negative and positive barns contained.

“As a pig vet, when I go out to a farm to battle PRRS, I will take all of the help that I can get,” Patterson says.

Final performance closeout numbers for the trial are still pending. There are plans for a repeat trial this fall with a new group of PRRS-positive pigs. “Some questions that remain unanswered are the effects that seasonal ventilation differences will have on air sampling, as well as potential differences in the viability of virus between rooms,” Patterson speculates.


Battling PRRS virus in young pigs is always a challenge, Patterson says, limiting the significance of the results using EPI Air compared to healthy pigs (the Utah example). “If you have healthy pigs, I think you can expect huge performance gains — but if you are battling PRRS, it is harder.”

And either way, there are benefits to be gained from a cleaner environment and a better working environment for employees, he says.  

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USDA Launches Beta-Agonist-Focused Certification Program

USDA logo reports that USDA has launched a certification program that allows companies that produce livestock, beef and pork products to market their products using “Never Fed Beta Agonists” labels.

USDA’s Agricultural Marketing Service requires companies seeking to participate in the Never Fed Beta Agonists program to submit documentation that meet several of the agency’s specific Process Verified Program (PVP) or Quality System Assessment (QSA) program requirements, among others.

The designation covers meat from animals that were never fed beta agonists and is free of beta agonist residues.

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The growth enhancer such as ractopamine fed to hogs and zilpaterol fed to cattle have become increasingly controversial. China and Russia have long banned ractopamine. In recent months South Korea and Taiwan discovered traces of Zilmax (zilpaterol hydrochloride) in U.S. beef and in some cases expanded inspections or temporarily suspended imports of the beef.

Merck Animal Health suspended sales of Zilmax in August and launched a review over concerns that the drug may be negatively impacting a minority of the animals fed the supplement.

Visit here. 

U.S. Pork Center of Excellence Offers Web-Based National Swine Reproduction Guide

U.S. Pork Center of Excellence Offers Web-Based National Swine Reproduction Guide

This week the U.S. Pork Center of Excellence (USPCE)  launched the National Swine Reproduction Guide, a web-based application offering easily accessible information to hog producers. This troubleshooting and management guide, built in a user-friendly and intuitive format, contains extensive information and support contained in more than 1,000 fact sheets and references.

"This guide is designed to help producers identify the source of the reproductive problem they are experiencing and, through research-based fields, provide information directly related to that problem," said Chris Hostetler, animal science director at the National Pork Board.

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The National Swine Reproduction Guide is only available as a web application and is easily accessed through personal computers, smart phones and tablets. 

The guide uses a reproductive decision tree specifically designed in an easy-to-use format that utilizes simple navigation. The decision tree begins with three categories: gilts, sows and boars (semen). After selecting a category, a list of potential issues are available from which to choose, such as "low farrowing rate" or "too small of a gilt pool." Once the topic is selected, the decision tree uses a series of questions to help narrow the search on the issue. After choosing the question that best fits the original problem, an answer is provided in the form of a fact sheet with viewable references.


Visit the USPCE website to purchase an annual license that enables use of the guide at


Established in 2005, the U.S. Pork Center of Excellence is a collaborative public/private partnership providing academic expertise in research, teaching and extension to address the complex issues facing the pork industry. The center is located in the offices of the National Pork Board in Des Moines, IA. USPCE partners include governmental agencies, national pork industry associations, 17 state pork producer associations and 24 land-grant universities.


Beef Facilities Conference Scheduled Nov. 21

A one-day “Beef Facilities Conference” will be held November 21 at the Best Western Plus Ramkota Hotel and Conference Center in Sioux Falls, SD. The conference is a cooperative effort of Iowa State University Extension and Outreach, University of Nebraska-Lincoln Extension, South Dakota State University (SDSU), USDA Agricultural Research Service and the USDA National Institute of Food and Agriculture.

“The purpose of the conference is two-fold,” says Beth Doran, Iowa State University (ISU) Extension and Outreach beef program specialist. “Morning sessions feature environmental research with these facilities; afternoon sessions focus on building management and cattle performance.”

The morning session includes results of the two-year air emissions study in mono-slope barns, air quality regulations and how to capture, manage and use nutrients produced in beef barns.  The two-year air emissions study looked at the emissions of gases and dust and is one of the first studies looking at air quality in these barns. 

Afternoon sessions involve two panels – a producer panel discussing building management in different style barns and a university panel discussing cattle performance.  Four styles of facilities will be featured – mono-slopes, hoops, slatted floor deep-pit barns and open lots. 

Conference information, registration materials and potential sponsorship are available on-line at

Webcast Series Addresses Manure Nutrient Recovery

The next eXtension Livestock and Poultry Environmental Learning Center webinar, Capturing Valuable Nutrients from Manure, is scheduled for Nov. 15 at 1:30 p.m. (central time). This webcast is the first in a series of three webcasts that will provide information on the need to capture nutrients for recycling off-farm, global phosphorus supplies, and technologies that are being used on-farm to capture nitrogen and phosphorus from manure. These webinars are open to the public and available at no charge.  

Learn more about the first webinar from this eXtension flyer at

Ohio Phosphorus Task Force Issues Report

The Ohio Phosphorus Task Force II issued its final report this week on findings to support reduction of phosphorus loading and associated harmful algal blooms in Lake Erie and surrounding watersheds.

Recommendations include the development of loading targets for the Maumee River watershed and other Lake Erie tributaries, expansion of current phosphorus monitoring programs, and suggestions for working with area stakeholders to improve soil health, nutrient retention, and proper timing and placement of applied fertilizers.

The report was created by a diverse working group of industry professionals including experts from Ohio State University's College of Food, Agricultural, and Environmental Sciences and its outreach arm, Ohio State University Extension; Ohio State University's Ohio Sea Grant and Stone Lab; the Ohio Department of Natural Resources; the Ohio Department of Agriculture; the Ohio Environmental Protection Agency; and the Lake Erie Commission.

 "This report gives us an excellent road map for moving forward in phosphorus management in the Lake Erie watershed," said Ohio Sea Grant Director Jeff Reutter. "The challenge will be on the implementation side; that is to implement the 20 recommendations in this report."

Harmful algal blooms in Lake Erie most often consist of Microcystis, a cyanobacterium -- more commonly called blue-green alga -- and can produce a number of toxins hazardous to the ecosystem, animals and people. The toxins can be removed from drinking water drawn from the lake, but the process increases the cost of water treatment.  In addition, harmful algal blooms can severely reduce tourism income, as recreational water use can be made dangerous by the toxin, or unpleasant by layers of blue-green algae floating on the water's surface.

The task force will continue to meet on a regular basis for further evaluation and publication of state and regional phosphorus management efforts.

The complete report can be found at:

2013 Nutrient Management Standard Released in Iowa

USDA’s Natural Resources Conservation Service (NRCS) recently released the new Iowa Nutrient Management Conservation Practice Standard – the guiding document for implementing nutrient management plans for Iowa farmers.

Iowa’s 11-page Nutrient Management (NM) or 590 Standard provides farmers guidance regarding managing the rate, source, placement, and timing of the application of plant nutrients and soil amendments. This includes animal manure, commercial fertilizer, legume credits, green manure, and crop rotations. The Standard is updated every five years.

According to Eric Hurley, Iowa NRCS nutrient management specialist, the Nutrient Management Practice Standard helps farmers and the state’s natural resources. “The Practice Standard helps farmers plan nutrients for optimal crop production and fully utilize manure or organic byproducts as plant nutrient sources,” he says. “It also protects water quality by minimizing agricultural nonpoint source pollution and helps improve soil health.”

The National Laboratory for Agriculture and the Environment in Ames, IA, led a comprehensive revision effort, according to Hurley, with input from Iowa State University (ISU). They sought and utilized input from agricultural organizations, environmental groups, private agronomists, and other stakeholders.

Compared to the 2008 Iowa version, the 2013 version has some important changes, including:

·        Changes to “sensitive” areas. Several changes were made to the nutrient application criteria to minimize the contamination risk near areas deemed sensitive from a water quality standpoint. A 50-ft. filter strip can be used in place a of a 200-foot setback when surface applying nutrients near sensitive areas. As an interim mitigation practice near areas such as tile inlets, cover crops or a no-till cropping system may be used to mitigate runoff risk. The application criteria now apply to most nitrogen and phosphorus sources, not just manure.

·        New 50 Degrees or Below Provision. Iowa farmers have always been encouraged to wait to apply fall anhydrous ammonia until soil temperatures reach 50 degrees, trending colder. Now other high- ammonium sources, such as liquid swine manure, are included in these criteria for fall application.

·        Rescue Nitrogen Application is OK. Untimely heavy spring rains caused farmers to lose large amounts of nitrogen over the past several years. A new provision allows farmers to utilize a “Rescue Nitrogen Application” that permits an additional nitrogen application when weather causes a significant loss of nitrogen. The Standard specifies ways to formulate and evaluate management alternatives for rescue nitrogen applications. “Even with good management, farmers can lose nitrogen when excessively heavy rains hit their fields,” says Hurley. “Many of Iowa’s field agronomists requested this provision be included in the standard, and for good reason.”

·        Additional Practices for Controlling and Trapping Nutrients. To help trap nitrogen, conservation practices such as cover crops, filter strips, bioreactors, and nutrient treatment wetlands (CREP wetlands) were added to the practice list. To control and trap phosphorus, practices such as no-till, terraces and grassed waterways that control erosion and trap sediments are included.

·        Equipment Calibration. Equipment used to apply fertilizer and manure must be calibrated to assure that what is planned to be applied is actually applied. This provision is included in the Operation and Maintenance section of the Standard. Lori Schnoor, district conservationist for NRCS in Jackson County, IA, says calibrating manure spreader equipment, for example, will benefit producers both economically and environmentally. “It may take extra time to calibrate equipment, but in the long run it will save you money,” she says.

·        Yield Goal Now Realistic Yield Potential. Any reference in the old standard to “Yield Goal” was changed to “Realistic Yield Potential” in the new standard. This change provides for simpler ways to estimate yield to determine nutrient removal rates.

·        Manure Testing Requirement. A lab certified through the Minnesota Dept. of Agriculture Manure Testing Laboratory Certification Program (MTCP) will be used to complete manure tests. Learn more at

·        Biosolids Included as Plant Nutrients. Biosolids like sludge and food processing waste are now included as sources of plant nutrients, recognizing that they are also a valuable fertilizer source.

·        Guidance for Adaptive Nutrient Management. This provision encourages producers to conduct on-farm research to make better nutrient management decisions. “We encourage farmers to set up their own on-farm strip trials to test nutrient management practices,” says Hurley.

The Iowa Nutrient Management Standard is available on the Iowa NRCS website at Click on the “Iowa Conservation Practice Standards” link under “Helpful Links” on the home page to learn more.

Field Drainage Research May Help Protect Water Quality

Field drainage installations called blind inlets have been adapted by U.S. Department of Agriculture (USDA) scientists for managing agricultural pollutants in the Lake Erie watershed. These systems, which were developed by Agricultural Research Service (ARS) scientist Doug Smith and others, are so effective that farmers who install them are eligible for financial assistance through USDA's Environmental Quality Incentives Program. ARS is USDA's chief intramural scientific research agency.

Prairie potholes in crop fields have no natural outlets and are prone to ponding, so farmers often install tile risers to drain away excess water. These risers are perforated vertical pipes that extend a foot or more above the soil and connect directly to subsurface tile drainage networks.

Water drained from potholes by the risers is discharged via the subsurface drains into the nearest field ditch without any filtration or processing.

Smith, who works at the ARS National Soil Erosion Research Laboratory in West Lafayette, IN, studied how water quality differed between pothole drainage that passed through tile risers and drainage that passed through blind inlets. Often agricultural runoff drained from the potholes in northeast Indiana's St. Joseph River watershed eventually reach Lake Erie. A blind inlet is similar to a French drain that channels excess water away from a building foundation. Smith constructed blind inlets by digging a square pit three feet deep at the lowest point of each pothole and then strategically arranging layers of gravel, tile lines, and related drainage materials in each pit.

Water samples collected from drainage channeled through risers consistently showed the highest levels of total phosphorus lost from the fields—as high as 1.73 ounces per acre. In addition, almost all these samples had higher levels of sediment, soluble phosphorus, total phosphorus, and nitrogen than water that drained through blind inlets. Phosphorus loads in samples from the blind inlets were 78% lower on average than phosphorus loads in samples from the tile risers, and average sediment loads were 79% lower.

Read more about Smith's studies in the October 2013 issue of Agricultural Research magazine.

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Agricultural Groups Wary of Proposed EPA Clean Water Act Rule

Agricultural Groups Wary of Proposed EPA Clean Water Act Rule

Environmental Protection Agency Administrator Gina McCarthy faced some tough questions during a Congressional Science, Space and Technology Committee hearing today about the agency’s alleged use of undisclosed data to justify a rigorous regulatory agenda. This comes after last week’s Bloomberg News report indicating that the EPA and U.S. Army Corps of Engineers are proposing a rule that has the potential to vastly expand the types of waters that fall under the Clean Water Act (CWA). The National Pork Producers Council (NPPC) says the proposed rule is a direct contradiction to recent U.S. Supreme Court opinions, and that the rules could potentially impact producers’ ability to spread manure on their own land.

NPPC says the draft regulation would bring under CWA jurisdiction man-altered and man-made water bodies, including farm ditches, tile drainage and field filter strips. Even wetlands that are “many miles away” from jurisdictional water could be regulated, according to NPPC.

The Supreme Court has limited EPA’s and the Corps’ jurisdiction under the CWA in several instances, ruling that it cannot be based on a mere connection to a navigable water or extend to waters far removed from navigable waters.

If the draft rule becomes final in its current form, NPPC says that EPA and the Corps could potentially have jurisdiction over large tracts of state and private lands, and CWA permits would be required for a host of activities on them. Farmers could be required to obtain permits to apply manure, fertilizer or pesticides, for example.

Science, Space and Technology Committee Chairman Lamar Smith (R-Texas), raised concerns today that such a “power grab” undermines states’ rights and increases federal control of private property that, as he says, “could lead to the EPA telling us what to do in our own back yard.”

In a news release issued late today, Chairman Smith says, “The EPA, like every other governmental institution, answers to the American people. Everyone agrees that we need to protect the environment, but we should do so in a way that is open and honest. It appears that EPA bends the law and stretches the science to justify its own objectives. We need to know whether the agency is telling the truth to the American people. The EPA must either make the data public, or commit to no longer using secret science to support its regulations. I will introduce legislation in the next few weeks that will stop the EPA from basing regulations on undisclosed and unverified information.” 

McCarthy told the committee that sound, high-quality, transparent science serves as a backbone to EPA decision making. McCarthy’s prepared remarks can be seen here. 

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Administration Nears Decision on Ethanol Policy



The U.S. government may be about to reduce the federal requirement for blending ethanol into fuel, which has major ramifications for farm states, food prices and energy, according to a report yesterday in Politico.

As early as Tuesday, the Environmental Protection Agency (EPA)  is expected to announce how many billions of gallons of ethanol it will require refiners to blend into gasoline and diesel fuel in 2014. If it sticks with a draft version that leaked in October, the agency will lower the amount to 2012 levels.

The debate over how much ethanol should be forced into the American gasoline supply pits powerhouse special interests against each other. On the pro-ethanol side: the renewable fuels industry, corn growers and many Midwestern lawmakers. On the anti-ethanol side: the oil industry, restaurant owners, livestock and poultry producers and, increasingly, a disenchanted environmental movement that no longer believes the plant-based fuel is a greener alternative to fossil fuels. In addition, a new generation of tea party Republicans — viscerally opposed to government mandates and fuel subsidies — has joined the fight against ethanol.

The EPA’s decision, just three months after the agency hiked the long-overdue 2013 ethanol mandate despite the oil industry’s pleas, could mark a shift in momentum in the biofuels wars. Congressional leaders are talking about rewriting the law that created the mandate, while oil lobbyists continue to fight to repeal it entirely.

Read the rest of the article at