Biosecurity:  Shore Up the Weakest Links on Your Farm

When it comes to biosecurity, there are many common protocols that should be followed on every farm. But still, one size doesn’t fit all. Success depends on tailoring biosecurity for every site, with everyone knowing and carrying out the plan.

“The temptation is to create a laundry list of biosecurity steps, hand it to employees or growers, and check that off the to-do list,” said Lisa Becton, DVM, director of swine health information and research for the Pork Checkoff.  “The hitch is that priorities may be unclear, and people may feel overwhelmed so they do little or nothing,” Becton said. “Biosecurity measures are somewhat universal for disease prevention, regardless of the pathogen. But farmers have to review and determine their own farm’s risk level, which will drive how and what biosecurity steps need to be taken.  “By identifying risk events or vulnerabilities – the weakest links – within a production site, a producer can break biosecurity into manageable pieces and address specific needs.”

Two principles guide on-farm biosecurity, according to Jean-Pierre Vaillancourt, DVM, a biosecurity expert at the University of Montreal. 1) Reduce the source of contamination through materials, animals, people, equipment, etc. 2) Separate affected animals from healthy ones.  “Producers should separate the outside from the inside to prevent the pathogens from reaching animals,” Vaillancourt said. “Of course, with larger facilities closer together, the infection pressure per square mile has increased.”  That includes more pigs, people, vehicles, equipment, insects and more risk events, according to Clayton Johnson, DVM, Carthage Veterinary Services, Carthage, Illinois.  “A pathogen doesn’t care how it gets into the farm. It will exploit whatever access you give it,” Johnson said.

Draw a Strict Line of Separation

“If you don’t have a ‘line of separation’ on your farm and maintain it, you don’t have biosecurity,” Becton said. “In fact, you may need to set up several lines within a site, because biosecurity is not just about exposure from the outside, but also the lateral spread of disease.”  At its most basic, a line of separation designates the outside (contaminated) area and the inside (clean) area. Think in terms of drawing a line in the sand – a point at which certain parties must not cross.

For example, identify a line where the animal transporter is not to cross and where farm or market personnel are to remain. If a barn worker does cross it, they cannot return to the clean side. The separation line must be clearly marked, with individuals made aware of where it exists in every situation.

Lines of separation for transporters might be at the cab of a truck, the back of a trailer or a loading chute. Within a production site, the shower or bench entry would be the ‘dirty’ side, while the shower exit would represent the clean line. Another line could be a designated driveway that feed trucks must use to control traffic flow and potential exposure.

The take-home message? Approach every contact with a site or market as if it could contaminate a truck, trailer or herd. The one time you don’t follow biosecurity rules could be the time when your herd will get sick.

Zeroing in on Biosecurity Risks

Identifying risk events commonly associated with disease outbreaks has been a priority for Derald Holtkamp, DVM, professor, veterinary diagnostics and production animal medicine, Iowa State University. Starting in 2013 with a grant from the Iowa Pork Producers Association, he developed a disease outbreak investigation system for use by trained veterinarians.

Further support from the Swine Health Information Center has expanded the effort, including making the materials available on its website at Holtkamp also is evaluating risk events within a database to identify patterns.

The effort started with porcine reproductive and respiratory syndrome (PRRS) outbreaks. Now, with 19 outbreak investigations under his belt, Holtkamp has found some commonalities (  Employee entry, removal of culls and scheduled repairs are events most frequently rated “high risk” for biosecurity, Holtkamp noted. But the frequency of most any event increased the farm’s disease risk. The outbreak investigations have improved PRRS biosecurity strategies and shed light on other risks.  “The more disease investigations we do, the more insights we gain and the more data we collect,” Holtkamp said. “This helps producers refine their biosecurity plans.”

Collective Momentum Needed to Protect U.S. Herd

Johnson said that on the farm, on a daily basis, “It’s hard to know when you’re the biosecurity hero, that you did something correctly to prevent an outbreak. So, it can be hard to maintain urgency.” He added, “But with domestic diseases, such as PRRS and porcine epidemic diarrhea virus and the global threat of African swine fever (ASF), it’s everyone’s responsibility to embrace the urgency. Start by picking a link in the chain that you’re going to work on today and build from there.”

It’s also critical to be transparent and to collaborate.  “If you have a secret sauce for biosecurity, share it,” Johnson said. “If something like ASF isn’t enough of a common enemy to unite us to share best practices, I don’t’ know what is.” For producer resources and tools about increasing your farm’s biosecurity, visit and search for “biosecurity.”

Pick the Low-Hanging Fruit

Whether you’re drawing up a new biosecurity plan or revising a previous one, you need to involve your herd veterinarian and employees in the barn, according to Jean-Pierre Vaillancourt, DVM, University of Montreal.  “Let everybody contribute biosecurity ideas,” Vaillancourt said. “Not only will it give them ownership, but it will also build trust.

Unrealistic expectations lead to non-compliance. If something is too complicated or doesn’t make sense, it will not get done.”  And people will make mistakes, noted Derald Holtkamp, DVM, Iowa State University.  “It’s important to have layers of biosecurity to provide redundancy,” Holtkamp said. “When mistakes are made in one layer, there is another layer to prevent an outbreak. A biosecurity system with multiple layers is more likely to be robust enough to tolerate mistakes.”  “There is some low-hanging fruit that can bump up your farm’s biosecurity,” he said. “Concentrate on inexpensive things that are easy to do.”

These include the following steps that all pig farms should be addressing at a minimum today:

1) Define the first clean/dirty line

“This starts with the walls surrounding the pig barns,” said Clayton Johnson, DVM, Carthage Veterinary Services. “The inside is clean; the outside is dirty. Be strict that crossing the line requires some level of hygiene.”  Painting door frames and concrete or designating areas with colored duct tape provide visual reminders.

2) Keep up with maintenance.

Good maintenance goes hand in hand with a solid biosecurity plan. When equipment breaks down or feed bridges, it’s easy to break biosecurity rules.  “Or you may need to bring someone in from the outside for the repair, and because you think they don’t have much exposure to pigs, you bend the rules,” Holtkamp said. “Don’t reduce your focus on biosecurity.”

3) Check for leaky bins.

In line with maintenance, ensure that feed is not spilling out and building up under bins. It’s an invitation for birds, rodents and other wildlife. It may cost some money to fix, but so does the wasted feed.

4) Share farm rules with incoming crews.

While onsite workers should know the biosecurity rules, occasional visitors, such as vaccination and loadout crews or repairmen and technicians, pose higher risks. Johnson suggests calling ahead of time to explain the biosecurity rules, including how to enter the farm, what clothing/showering requirements are in place, and how to recognize the clean/dirty lines.  “A 15-minute phone call goes a long way in helping crews comply with biosecurity rules,” Johnson said. “Be sure someone onsite confirms it gets done.”

5) Prioritize loadouts.

Prioritize clean trailers for the first cut of market hogs because there are not enough truck washes, time or personnel to wash, disinfect and dry every truck/trailer every time, Johnson says.  “You have another four to five weeks to empty the barn, so you don’t want to expose the remaining pigs to a disease that could cause some serious consequences,” he said. “Staged loading is another idea gaining traction.”

6) Provide showers: yes or no.

On sow farms, showering in and out is a fixture, but it is less common on growing-pig sites.  “A shower’s not necessary, but you should change into dedicated farm clothes and shoes and wash your hands,” Johnson said.   “Emphasize handwashing and honor all clean/dirty lines. If there is a shower, its effectiveness depends on how it is used, its location and flow from clean to dirty sides (including towels – clean side only), how clean it is and how it’s supplied.”

7) Avoid mistakes bringing in supplies.

The pass-through windows, UV chambers and disinfectant rooms for incoming supplies are common areas for mistakes.  “We get addicted to those magic areas,” Johnson said. “Just because you send items through doesn’t mean they are magically clean.”  All surfaces need to be exposed. For disinfection, contact times matter and that differs by the disinfectant. Everything coming into a barn should be addressed, but some prioritization is helpful, Johnson noted. For example, the new microwave purchased for the lunchroom is different than the welder borrowed from another site.

8) Follow biosecurity plan when removing culls and mortalities.

“Both are high-risk events, and respecting the clean/dirty line is a must,” Johnson said. “For culls, apply the staged loading concept. If rendering is required, an off-site pick-up location is important, but recognize that it’s contaminated and your vehicle will be too. After all, the rendering truck has known exposure to ‘sick pigs.'”  Although not a low-cost solution, both veterinarians recommend prioritizing biosecurity when designing new production sites/buildings or when remodeling.  “Sometimes changing behavior will only go so far without a design change,” Johnson said.

Rethink the Clean/Dirty Line with Staged Loading

Transporting live hogs presents a significant biosecurity risk, with more challenges than solutions. But “staged loading” is a method that veterinarians Derald Holtkamp is researching and Clayton Johnson is applying on some farms.  “It’s a low-cost fix, and a way to add another layer to the process,” Holtkamp said.”

Here’s how it works:

The truck:
Inform the truck driver about the procedures before arriving. Always consider the truck dirty, so the first dirty line is the back of the trailer. The driver backs up to the loading chute and can only enter the trailer, preferably through a side-entry door. You can require the driver to have a side-entry, Johnson said. The driver must change boots/clothes per farm protocol.

The Chute:
The second dirty line is the last door you can shut between the loading chute and the barn/pigs, Johnson noted. One person remains in the loading chute to accept pigs from the barn and to move them up into the trailer. This person does not enter the barn until loading is complete and follows all entry procedures.

The barn:
Two (or three) people in the barn move pigs out of pens and down the aisle to the door/loading chute. The door will shut so pigs cannot backtrack.

The equipment:
Sorting boards, paddles, any equipment needed to move pigs remain within the assigned clean or dirty side.  “On many farms, this should be relatively easy to adopt,” Holtkamp said. “It’s not 100%, but it adds another layer.”

It All Hinges on People

Biosecurity training and auditing get a lot of lip service, but what do they really mean?  “The important point is to train frequently and formally, not just for new hires and not a topic over lunch,” said Derald Holtkamp, DVM, Iowa State University. “Put it on a schedule; otherwise it’s easy not to follow through.”  This is especially critical because of the labor shortage and high turnover rates challenging agriculture today.

“When we talk about training, we’re talking about changing habits,” said Jean-Pierre Vaillancourt, DVM, University of Montreal. “Never underestimate the importance of talking to employees and sharing knowledge.”  Also, remember that you’re training adults, he said.  “They want to know why you’re asking them to do something,” Vaillancourt said. “They want to know about disease transmission and the impact on the farm, the animal and themselves. After all, they’ll be dealing with the aftermath. Give them tools to succeed. Establish markers so that you can identify progress or where to make changes.”

Be sure to communicate often and thoroughly that everyone matters.  “When it comes to compliance, we know that people doing the most basic jobs tend to consider themselves so unimportant that if they don’t follow procedures, it may not matter,” Vaillancourt said.  Whether you talk about monitoring or auditing protocols, both involve observing, correcting the process if needed and confirming what’s right. Also, audits have to be done by someone with authority.  “The goal is continuous improvement, so it’s equally important is to get feedback from people in the barn,” Vaillancourt said. “Find out why something isn’t getting done or working and be willing to make adjustments.

Finally, have employees sign a form following training or an audit, which further emphasizes its importance.

How Has the Threat of ASF Changed the Game?

“Even though African swine fever (ASF) is not now nor ever has been in the United States, the expanded global threat demands razor-sharp attention,” said the Pork Checkoff’s Lisa Becton, DVM. “On the plus side, steps that we currently employ to prevent other diseases will be important to protect against ASF.”  Of course, there are some additional steps that pig farms are starting to put in place.

No international visitors – It’s best not to allow any international visitors onsite, says Derald Holtkamp, DVM, Iowa State University. As for U.S. personnel who have visited ASF-affected countries, five to seven days of downtime is a must.  “It’s the showers during that time that are important because we know the virus survives a long time,” he said. “Also, no shoes or clothing from ASF-affected countries, even items that were not worn on pig farms, can come onto a U.S. farm.” Add a question to the visitors’ log specific to travel in ASF-affected countries for anyone entering the farm.

No pork foodstuffs on the farm – “ASF is different disease-wise; it survives in processed and dried pork for a long time,” Holtkamp noted. “Seriously consider catering lunches as an employee benefit and as a biosecurity measure; it gives you control.”

Increased insect control – Although soft ticks (Ornithodoros) associated with ASF transmission are not a concern domestically, biting flies and ticks can serve as a mechanical vector. “We need to up our game on insect, pest and rodent control,” Holtkamp said.

Increased farm security – Consider perimeter fencing and security cameras to monitor activity. At the very least have gates that someone can’t simply drive around and doors with keypad access, Holtkamp said.

Becton also advises building your farm FAD awareness:

  • Know the clinical signs of ASF, and other foreign animal diseases (FADs) and how to determine if something is not right. (Available at
  • Pre-Identify a herd veterinarian to contact and assist if you suspect clinical signs of an FAD.
  • Post important contact information by the farm phone, including names of herd, state, and USDA veterinarians, in case of an animal health event.  “Have a current premises ID number for the site where the pigs are located – not at a main office or house,” Becton emphasized. “Use that PIN now for all animal movements and lab submissions and sign up for the Secure Pork Supply plan at”

U.S. Vigilant as ASF Marks One Year in China

A year has passed since China acknowledged the presence of African swine fever (ASF) in its swineherd. More than 40 countries have reported the deadly virus either in wild or domestic pigs during the past five years, according to the World Health Organization for Animal Health. Keeping U.S. pigs free of this ongoing threat hasn’t been easy, and doing so successfully has taken an integrated, collaborative approach, according to National Pork Board President David Newman, a pork producer who represents Arkansas.

“We are definitely in a better position today to deal with the threat of ASF than we were a year ago,” Newman said. “That said, we can never be too prepared with a devastating disease like this. What I like though is how our industry has pulled together over the past 12 months in the spirit of collaboration to get the job done.”

The Pork Checkoff has taken a leading role in collaborating with multiple government and industry partners to protect the United States from ASF. Primary partners in this effort include USDA, the National Pork Producers Council, the North American Meat Institute, the American Association of Swine Veterinarians and the Swine Health Information Center. The American Feed Industry Association also has played an essential role in feed biosecurity issues.  “Collectively, we’ve increased our defenses against ASF and other costly foreign animal diseases,” Newman said. “When you consider our progress and what’s on the horizon in terms of tools to help every U.S. pig farmer fight threats such as ASF, it’s reassuring.”

For producer resources and tools about ASF, including more tips on increasing your farm’s biosecurity, visit and also search for “biosecurity” at