September 3, 2024
"Prepare for the unexpected" Selko webinar episode offers holistic strategy for managing salmonella risk on poultry farms
Selko, the feed additives brand of Nutreco, is discussing the threats that salmonella poses across the feed-to-farm chain and sharing a holistic approach to mitigating this risk in the latest installment of its recorded webinar series.
"Salmonella Control – Prepare for the Unexpected" may be watched in its entirety here:
The content was presented in a live global webinar earlier this summer.
Contents discussed in the webinar puts the spotlight on gram-negative bacteria Salmonella, which causes Salmonellosis, a food-borne illness transmitted primarily through eggs, poultry, and unpasteurised milk.
While approximately 600 million cases of foodborne illnesses and 450,000 deaths occur annually, the public health threat posed by salmonella can be reduced through measures that include proper food handling, cooking measures, and hygiene such as handwashing. Diligent attention throughout the poultry value chain can significantly reduce the risk of salmonella contamination across the food chain and help keep it from reaching the final consumer.
Controlling salmonella is not easy as the bacteria are prevalent in a range of environments. Salmonella thrives in temperatures between 7○C and 45○C and environments with a pH range of 4-9 and water activity of 0.95-99. These warm, moist conditions are common in raw materials, on the farm, and in feed production facilities. Opportunities for cross-contamination are abundant.
Environmental risk factors include infected animals, wild birds, and rodents. Equipment, such as vehicles at the farm and conveyor belts at the production facility, can harbor salmonella. As salmonella is resilient, recontamination can occur, harming animal productivity and increasing production costs.
A special concern is that many of the strains of salmonella found on poultry farms have demonstrated resistance to antibiotics.
Management starts with measurement and structured sampling
Effective salmonella management starts with measuring and mapping the microbial blueprint at each critical control point (CCP) across the supply chain – from raw ingredients to feed processing, storage, and transport of the final product. Continuous measurement is essential, as pathogen loads fluctuate over time.
A structured sampling plan should specify objectives and include specific CCPs. On the poultry farm, key CCPs include raw material receiving areas, storage facilities, equipment used in mixing and grinding, thermal treatment areas including heat as well as cooling and drying areas, finished product storage, and transport.
A regular sampling schedule should be supplemented with event-driven sampling, such as when rodents are detected. Developing standard operating procedures and training personnel on sampling procedures is critical. Workers collecting the samples should be provided with gloves, swabs, and hygienic containers.
Due to salmonella's hidden presence, workers should take enough samples – about 300-600 grams. Once samples are collected, prompt, accurate labeling, and documentation will help assure traceability across the supply chain. The analysis report generated by an accredited laboratory should be reviewed and interpreted to inform actions.
Implementing a holistic approach to mitigation efforts
Sampling detection is not foolproof. Clusters of salmonella may form in some spaces while other areas test clean.
Given the complexity of mitigating a bacteria with more than 1,600 serovars, results of lab analysis should be considered as the "perceived prevalence." A longitudinal look at data can provide a richer overview of the salmonella situation on a farm or at the feed mill.
Careful attention should be paid to risk factors including breeders, the hatchery, and areas with elevated levels of moisture/humidity. Implementing interventions at each of these steps provides a consistent, systemic, and persistent approach to mitigating risk. For example, factors to assess on the farm include other animals and wild birds, workers, newly arriving chicks, feed and water lines, placement and movement of animals, cleaning, and disinfection procedures.
Two of the most frequent sources of salmonella infection on the farm are new chicks arriving in the house and feed. In storage and at the feed production facility, raw materials pose a risk as they are nutrient-rich and have an optimal pH level for Salmonella.
Like sampling, mitigation efforts must be holistic. Quality control measures at the mill should assess the quality of ingredients delivered to ensure they meet acceptable standards. Raw material handling protocols should be in place along with process controls, such as equipment to reduce microbial contamination. A continuous approach to managing salmonella and safeguarding both feed and food safety involves integrating monitoring, surveillance, structured sampling, and corrective actions.
It is very important to highlight that feed and water additives can contribute significantly to reduce the microbial risk, resulting in much lower salmonella incidence on-farm. However, they should not be applied as "magic bullets" to solve such a complex challenge. Feed and water additives should be applied as complementary intervention tools to several of the actions mentioned above, and as key components of a strong biosecurity programme.
- Selko