Oilseed meal is the highest Salmonella risk material used in feed formulations when animal protein meals are not used. Studies have found that oilseed raw materials such as soybeans and rapeseeds carry Salmonella detection rates of 36.6% and 23.8%, respectively. While Salmonella contamination of oilseed meals due to raw ingredients is unlikely due to intense heat processing, processors continue to be challenged by Salmonella.
How Does Salmonella Contamination of Oilseed Meals Occur?
Post heat, oilseed meal is put through an accelerated cooling process that brings the meal to ambient temperature. Condensation is often a by-product of this cooling process and helps create an environment in which Salmonella can thrive. Within these niches, Salmonella can establish resident colonies that increase the risk of post-heat contamination of oilseed meals. But how does Salmonella infiltrate the process post-heat?
Pathogen residence in oilseed processing can occur when:
- The entirety of the processed meal was not subjected to the total heat temperature or holding time
- Cyclone circulation of Salmonella-positive dust throughout the facility
- High oil content results in residues that protect Salmonella and facilitate its adherence to meal facing equipment
Contamination that occurs post-heat can be considered Salmonella recontamination when processors cannot eliminate Salmonella from the oilseed processing environment.
Anitox offers custom strategies for pathogen control in oilseed processing that ranges from flushing oilseed processing facilities with highly treated feed pathogen control materials and treatment of finished oilseed meal with feed sanitizers. Both of these strategies protect oilseed meals from recontamination.
Salmonella Prevention in Oilseed Processing
Preventing Salmonella contamination of oilseed meals requires continuous decontamination of oilseed processing facilities. Resident Salmonella can be eradicated by moving large loads of treated material through the oilseed facility, ensuring that every meal-facing surface is exposed to concentrated feed pathogen control materials. Subsequent flushes should be continued regularly to ensure that oilseed processing facilities remain Salmonella-free.
Prevention is further supported through comprehensive, holistic biosecurity programs. For example, producers can help reduce Salmonella proliferation within oilseed processing facilities by implementing engineering controls such as the insulation of cyclones to reduce condensation. However, while cyclone insulation may reduce the impact of condensation, it still fosters an environment suitable for Salmonella. Therefore, total Salmonella control in oilseed processing requires holistic biosecurity programs that continuously improve to support prevention strategies.
Decontaminating Finished Oilseed Meal
Oilseed meal treatment with feed sanitizers effectively controls the microbial load and reduces Salmonella. Studies have shown that feed sanitation controls Salmonella for at least 14 days post-treatment, providing continued protection against meal contamination during transport and storage. Feed sanitation helps producers ensure that they have complied with regulatory requirements for importing and exporting oilseed meals and have taken strides to protect their customers from introducing pathogens into the feed production chain.
Selecting Effective Salmonella Control Strategies for Oilseed Processing
Determining which Salmonella control strategy works best for your oilseed processing facility is dependent on your specific risk tolerance, and it’s essential to take the following under consideration:
- Customer and country Salmonella restrictions for import and export
- Facility age and design
- Salmonella status of incoming materials
- Current Salmonella prevalence in the oilseed processing facility and finished oilseed meals
Producers exporting oilseed meals to customers in countries such as Finland, which has a zero-tolerance for Salmonella, are subject to a higher cost if the finished meal is Salmonella-positive. As a result, these facilities typically employ preventative flush programs and, in some cases, choose to treat finished oilseed meals. However, some facilities produce oilseed meals for countries or customers who require proof of treatment, in which meal decontamination is sufficient.
A large part of deciding how to control Salmonella in oilseed processing is dependent on the processor’s understanding of current Salmonella prevalence within the operation. Salmonella prevalence is best determined by routine sampling within the oilseed processing facility and finished meals. Operations with a lower prevalence often employ routine feed pathogen control flushes. In contrast, operations with high Salmonella prevalence take action to mitigate Salmonella within the facilities and treat finished meals until facility prevalence is reduced.
To establish an accurate understanding of Salmonella prevalence within oilseed processing facilities, we recommend routine sampling on a 4–6-week basis. However, it is essential to note that the more sampling is done, the more accurate the prevalence assessment is.
Ultimately, oilseed processors choose to implement Salmonella prevention and decontamination strategies to protect themselves from the cost of a Salmonella-positive incident. Salmonella control strategies are designed based on perceived risk by each operation. Anitox is proud to help producers create a Salmonella control program that fits their facilities’ Salmonella objectives.
For more on Salmonella control in oilseed processing, click here.
Want to better understand your Salmonella risk?
Take our Feed Ingredient Risk Assessment to understand the Salmonella risk associated with various feed ingredients. If you’re ready to act immediately, you can contact a feed biosecurity specialist here.