Guard the Gate

A focus on biosecurity at the loading dock can impact animal health and productivity.

by Jeb Gent

Today’s pork producers know that biosecurity is essential in every aspect of pig production.

While the concept is simple - preventing the spread of pathogens coming into or leaving a farm - the many facets of an effective biosecurity program can be overwhelming and difficult to measure.

Taking a focused approach to analyzing biosecurity risks at an operation, prioritizing potential impact, and developing plans for continuous improvement are all key methods for keeping pigs healthy and productive.

Effective biosecurity systems include establishing protocols and selecting products that fit your operation’s needs, then training personnel and building a culture to ensure that protocols are carried out consistently and with integrity.

Biosecurity Matters for Animal Health and Bottom Line

While the return on investment for biosecurity practices is not as concise or easy to measure as other areas of an operation, such as feed costs or vaccinations, we know that achieving the ultimate goal of delivering healthy, full-value pigs through to finishing is only possible when effective biosecurity is in place. Your operation’s longevity relies on it.

Health issues in a herd reduce animal productivity, drain profits, and increase the lateral spread of viruses, creating a spiral that is difficult to get out of.

The cost of high-profile viruses such as porcine reproductive and respiratory syndrome virus (PRRSv) and porcine epidemic diarrhea virus (PEDv) is well documented and captures headlines.

The annual cost of PRRSv in the US national breeding and growing-pig herd was estimated at $664 million in 2011, and PEDv has been estimated to cost the industry $27 million a year.

Pork producers also face significant impacts from pathogens that don’t make the headlines but tend to persistently and consistently cause problems in finishing barns. A survey conducted by Holtkamp et al. found that the most common and challenging pathogens in finishing herds in the US were reported to be swine influenza, Mycoplasma hyponeumoniae, and PRRSv.

In short, the swine industry battles a large number of pathogens. It can pay dividends to keep them from the production cycle.

How do Pathogens Enter the Finishing Herd?

The list of potential entry points for pathogens into a finishing herd is long and includes nearly every aspect of an animal’s life and care.

For example, research has found that an estimated 55 percent of growing pig groups that are negative for PRRSv at placement are positive for the virus at marketing. This suggests that the virus was introduced sometime during the growing period, which can cause losses of approximately $2.29 per pig from higher mortality and slower growth.

Viruses require a vector or pathogen-carrying agent, such as an object, animal, person, dust, or even air, to carry a virus into the finishing herd for possible exposure.

Potential hazards include:

  • Animal movements, including weaned pig removal and introduction to the finishing barn, loading out finished pigs, and removal of mortalities;
  • Deliveries and removals, including feed and feed ingredients, propane and fuel, garbage removal, new tools and supplies, and manure removal;
  • People movements, including on-farm employee entry, repair and service personnel entry – both inside and outside a barn, veterinarian and other vendor entry;
  • Other animals and insects, including rodents;
  • Air and water entry through ventilation and the opening of barn doors.

The transportation process is especially challenging, with the potential for exposure at every step. There is a need for biosecurity to be understood and prioritized by multiple parties.

Don’t Forget the Loading Dock

While there are many sources of possible pathogen entry, one area that represents a great risk but is often ignored is the loading dock.

Loading out pigs headed to the processing plant can be seen as the end of those animals’ potential exposure, but remember that all other pigs in the building are at risk from the pathogens that find their way into the barn while their former barnmates are leaving.

Each time the barn door opens, viruses can travel in on dust or on contaminated boots, clothing, or personal objects. The loadout area of a barn can also produce a “vacuum effect” that sucks in air, along with contamination from the outside or the trailer, when doors are opened. This effect increases when outdoor temperatures are warmer due to higher fan ventilation speeds.

One of the most eye-opening demonstrations of potential risk in the loadout process is in Dr. Holtkamp’s 2020 trial using Glo Germ fluorescent powder. A mixture of fluorescent powder, wood chips, and obstetrics gel was placed just inside the rollup door of the livestock trailer.

someone sifting powder onto floor
Application of a hygiene powder or similar product can enhance biosecurity in finishing barns, loading chutes, and livestock trailers. -Photo Credit: Source: Ascension Ag

As pigs were loaded out, the loadout chute had a “consistently high level of contamination” from what the researchers determined were several sources. As pigs lunged up the chute and into the trailer, they lost traction, causing bedding and contamination to be thrown back onto the chute, whereupon load crew member boots, sorting panels, and pig handling tools all could have spread contaminated particles.

The research confirmed that the traditional loading protocol with crew members walking throughout the barn—bringing finished pigs from pens down the center alley and loadout alley, then back through the alleys to repeat the process with other pens—caused the contaminated particles from the trailer to be tracked back into the loadout alley, center alley, and even nearby pens.

Ultimately, if pigs are loaded onto a dirty livestock trailer or an improperly cleaned load chute is used, the risk of introducing new contaminants into the barn is dramatically increased.

Stepping up Biosecurity on the Loading Dock

Reviewing protocols and adding new practices for loading out finished pigs is a good start to minimizing the risk of pathogens entering barns. I’d recommend three areas to start with:

  1. Develop and follow protocols for washing trailers.
    Trailers that have been effectively cleaned before arriving at a barn are the first step in minimizing the potential for pathogens to enter a building. Establish a written protocol for your barns and operations, and then make sure that all drivers—whether employees or contractors—abide by that protocol.
  2. Implement a “staged loading” process.
    In the trial that we highlighted earlier, Dr. Holtkamp also compared the contamination between a conventional loading process and a staged loading process. Instead of just one line of separation in conventional loading, with the truck driver staying inside the trailer and all other crew members moving throughout the barn, a staged loading process establishes two lines of separation. Using a second line of separation between the loadout alley and center alley requires one person to stay in the load out alley to move pigs to the chute, while other personnel move the animals out of the pens and down through the center alleyway.
    The study showed that staged loading reduced the amount of contamination transfer to the barns compared to conventional loading, with the second line of separation providing an additional layer of biosecurity during the loading process.
  3. Apply hygiene powder or something similar.
    The application of a hygiene powder or barn lime can provide another layer of biosecurity in trailers and finishing barns. These powders can reduce moisture and pathogen load and create a barrier between vectors and viruses, with the added advantage of covering cracks, hinges, and other areas that can be hard to reach in standard cleaning practices. When choosing a product, make sure that it meets the specifications for your barns and protocols, including application timing, safety around animals, and expectations for antiviral and anti-bacterial properties.

diagram of conventional loadout process

diagram of staged loadout process
Illustration of conventional loadout and staged loadout processes. A second line of separation in the staged loadout process provides an additional layer of biosecurity during the loading process. Source: Reprinted from the “Evaluation of a staged loadout procedure for market swine to prevent transfer of pathogen contaminated particles from livestock trailers to the barn” article in the Journal of Swine Health and Production with permission from the author.

ChloraSorb livestock hygiene powder from Ascension Ag is one option that can be used in hard-to-clean or wet environments and provides research-proven performance to support animal health and facility biosecurity.

The best starting point is to work closely with your veterinarian to develop biosecurity protocols tailored to your operation, then ensure that employees, contractors, and service providers follow the protocols to help protect your pigs, barns, and farm, as well as the US pork industry, from outbreaks and productivity challenges.

Jeb Gent

Jeb Gent is the co-founder of Ascension Ag, a livestock biosecurity company located outside of Ames, Iowa. Solving niche biosecurity challenges on swine and poultry farms is a passion for Jeb. He loves helping farmers save animals, increase profits, and improve production processes. He and his wife have four young children and reside in Ames. In his free time, he enjoys family, friends, church, exercise, and farming.