Defend the Flock: Controlling Salmonella in Commercial Poultry through Biosecurity

October 5, 2020

Webinar Questions

COMMERCIAL:

Is any proactive testing recommended to check the situation of existing bacteria in the farm?

The best way to check for existing Salmonella within the house environment is to take swabs inside the 

house. Drag swabs or boot swabs are often used on the floors of the house to pick up bacteria and used 

for Salmonella environmental testing. Although these swabs are commonly used for the floor or the 

manure pits in the house, remember that these swabs can also be utilized in nest boxes, manure belts, 

and any other location within the house. 

Do any other insects besides the darkling beetle carry Salmonella?

Any insect that has gained access to a chicken house can carry Salmonella. Insects that tend to live in the 

poultry’s feces or manure have the ability to pick up Salmonella bacteria on their legs, bodies, and wings 

and can easily leave one house and travel to another, taking the bacteria with them. Flies are a major 

source of disease spread in general, and flies have been found to carry Salmonella between farms. 

With the increase of No Antibiotics Ever (NAE) poultry production, does feed need to be more 

protected?

Antibiotics are rarely useful as a treatment for Salmonella in poultry. Salmonella is often considered 

normal gut flora for poultry species and treatment for Salmonella rarely lasts. No Antibiotics Ever 

poultry production can be challenging, so we rely heavily on management practices to keep our poultry 

healthy. Management practices, including biosecurity, have increased as antibiotic use decreased. 

As a general statement, feedstuff suppliers and feed mills are becoming incorporated in many 

companies’ biosecurity plans. In the US, vertical integration of the poultry industry allows for the 

company to own all aspects of the production chain, including the feed mill, so that there is more 

control over the products that are taken into the poultry house. 

When controlling rodents, is there a concern about other animals or birds eating the rodents that 

have been poisoned?

Rodenticide toxicity in other animals that have eaten poisoned mice and rats are always a concern 

worth considering. Many commercial poultry houses now use of rat traps (such as the Tin Cat Mouse 

trap) that do not require rodenticides. You can also reduce the chances wildlife will be in the immediate 

area by ensuring that there is limited vegetation and trees near the house and cleaning up feed spills. 

For example, if there is concern about owls gaining access to poisoned rodents, then ensure that there 

are no nearby trees that would serve as a habitat for owls. 

What are major Hazard Analysis Critical Control Points (HACCP) for Salmonella?

A full HACCP program for Salmonella depends on the risk assessment for the farm. Major critical control 

points that have been identified for many farms have been as follows:

• Clean and disinfect between flocks. This includes cleaning prior to placement, cleaning clothes 

and shoes between different houses or flocks and cleaning equipment between houses or 

flocks.

• Monitor and control rodents and flies. Monitor rodent bait stations and replace bait as needed. 

If using a trap, ensure that the trap is being emptied regularly and tracking numbers can help 
producers understand rodent load on the farm. Fly traps and ribbons should be replaced 

regularly. Tacking up index cards in the house and counting fly specks (daily to weekly) can help 

estimate number of flies on the farm. 

• Place clean chicks or pullets. This can be done by knowing the status of the breeders or by 

testing the chick papers from the hatchery. 

• Monitor the environment. Environmental testing for Salmonella can help determine what the 

flock is exposed to, or what the flock is shedding.

In your opinion, do you think constant monitoring, culture, sensitivity and treatment will reduce the 

impact of Salmonella in the poultry industry, especially in developing countries like Nigeria?

Dr. Hofacre participated in a panel session during the 2009 World Health Organization Microbial Risk 

Assessment Series that addresses some of these concerns. A direct link to this document is found here:

https://apps.who.int/iris/bitstream/handle/10665/44211/9789241547901_eng.pdf?sequence=1

Given the role of breeder flocks on Salmonella load in broilers, does it make sense to use Salmonella 

vaccination in broilers or are other interventions more impactful? Can you clear or at least reduce the 

load in already infected birds?

Salmonella vaccination in breeder flocks is helping to accomplish two things. It gives the breeders 

immunity so that they are less susceptible to becoming infected, and if they do become infected they 

will shed much lower amounts of Salmonella into their environment and less into or on the egg. During 

Dr. Hofacre’s portion of the presentation, the following reference was provided that addresses this 

question: Appl. Environ. Microbiol. Vol. 76, No. 23, pp. 7820–7825. 2010.

What we have also found, is that the reduction or elimination of one Salmonella serotype within the gut 

microbiome can sometimes allow for other Salmonella serotypes to become more predominant.

Are more interventions in the live operation needed in order to reduce the risk of Salmonella in the 

processing plants?

There are, every day, new interventions that we learn about for the live side to reduce Salmonella in the 

plant. Unfortunately, what works for one complex or location may not be successful in other complexes 

or locations. This question is difficult to answer because it depends largely on the location of the house 

and the sources of Salmonella coming into the live operation as well as the interventions that are put in 

to try and stop that input.

How do you remove salmonella enteritidis (SE) from the environment inside and outside of barns?

The best way to keep SE out of a poultry facility is to ensure that the chicks placed at the farm are 

negative for SE and keep rodent and fly numbers down. Once SE is on the farm, the best option for 

elimination is to remove as much of the used litter or manure from the house as possible, dry clean the 

house to remove most of the organic material and then disinfect to kill bacteria. Salmonella requires 

moisture to live, so drying out the house has been shown to impact bacterial numbers. Prior to placing 

the next set of birds, do environmental testing to ensure that SE is not present. 

Treating outside of the house can be very challenging. Reducing vegetation and areas where water may 

puddle may help reduce the locations where you may be able to locate Salmonella in the outside 

environment. If there is concern that Salmonella is being “tracked” into the house from the outside, the 

best option is to implement biosecurity practices where shoes are changed upon entering the anteroom 

of the chicken house. Typically, this pair of shoes is stored in the anteroom and disinfected prior to 
entering and exiting the chicken house, but these shoes are not intended to be worn outside of the 

house. This reduces the risk that you would “track” in anything via your shoes. 

Are there biosecurity recommendations for pasture raised poultry?

Many of these recommendations are transferrable to pasture raised poultry. 

For pasture raised poultry, manure management is important. Ensure that the area is appropriate for 

the number of birds being raised on the property. Overloading the pasture with too many birds can 

result in an overabundance of manure buildup. Bird feces and manure can harbor Salmonella and attract 

insects, which can also bring Salmonella onto the property. 

Ensure that vegetation within the pasture and surrounding the fence are maintained to deter wildlife. If 

feed is offered, ensure that it is covered and maintained in an appropriate manner to reduce feed waste 

and spillage, which can attract rodents and flies. Salmonella needs moisture to stay viable, so reducing

water waste and spillage is also necessary. 

I have a small flock (24) in my backyard. Many of these tips are transferable to my situation. Are you 

planning to do this type of webinar for back yard chickens?

We hold separate webinars for backyard chicken owners, typically in February or March. We will 

consider including salmonella control in a future backyard webinar.

Do we need USDA permission to use those social media materials?

You can use the social media posts and other Defend the Flock materials without USDA permission, as 

long as no modifications are made.