Microbial risks, particularly from moulds and gram-negative bacteria, like Salmonella, pose significant challenges in food processing, with raw materials and varying temperatures and moisture levels creating optimal environments for growth. Early detection through comprehensive sampling plans at critical control points is essential for implementing tailored solutions.
Commercial Technical Manager – Raw Material Quality Programme
Selko
In the world of livestock husbandry, ensuring the well-being of animals is crucial. However, achieving this objective requires close attention to various aspects of feed production and management. Central to this undertaking is the careful consideration of feed ingredients, the regulation of moisture levels, the implementation of appropriate storage practices, and the responsible use of additives. At the same time, there is also a widespread and significant impact caused by microbial challenges on animal health. As a result, careful and constant attention is required to monitor and manage these challenges effectively. This discussion aims to explain the many different aspects of these important parts, showing how they all work together to support animal health and performance.
One of the top priorities is to carefully assess the ingredients we use in animal feed to prevent any risks that could harm the animals’ health. It’s crucial to select and examine these ingredients wisely to avoid any potential contaminants and ensure the feed’s nutritional value and safety. At the same time, we need to make sure the feed isn’t too wet or too dry. Finding the right balance is key to prevent harmful microorganisms from growing whilst maintaining valuable nutrients that animals need to thrive.
Moreover, the importance of appropriate storage conditions cannot be overstated. Maintaining hygiene during storage is essential to mitigate microbial contamination and spoilage, thereby safeguarding the quality and safety of feed materials. Throughout this process, specific additives help to protect the feed from harmful microorganisms and extending its shelf-life.
The connection between feed production, microbial challenges, and animal performance shows how important it is to take care of livestock in a holistic way. By carefully choosing ingredients, controlling moisture levels, storing feed properly, using additives wisely, and keeping microorganisms under control, everyone involved can create a good environment for the performance and health of animals.
Navigating these complexities requires a comprehensive approach. At Selko, we understand the significance of these challenges and provide solutions that address them effectively. Our expertise in microbial risk management in feed and feed ingredients makes us well-equipped to support stakeholders in overcoming these obstacles and contributing to the health and well-being of livestock. Selko’s raw material quality programme focuses on three pillars, namely Analysis, Technical application, and Management. This allows us to identify risks in a timely fashion and proactively control these risks.
ANALYSIS
Gram negative bacteria like Salmonella can stay dormant for several years, while they await the correct environment to grow. They thrive in an optimal temperature of 37°C however they can also survive at very low temperatures and in a varying pH of between 4-9. Salmonella is nearly impossible to eliminate, therefore, it needs to be controlled before it goes into the multiplication phase and exponential growth takes place. Any raw material that has gone through processing tends to have a higher risk for Salmonella contamination due to free water being present. This free water provides the perfect environment for bacteria to grow. Combine that with the optimal temperature and you will have exponential growth.
In addition to gram-negative bacteria, the challenge of mould is also very prevalent in grains. Mould growth can occur in the field before harvest, increasing the risk as it is put into storage. Higher moisture levels coupled with inadequate storage facilities can pose a big problem and cause a lot of spoilage quantitatively but also qualitatively. Mycotoxins, a secondary metabolite of moulds, can further degrade the quality and safety of stored grains. Hence, effective mould control can help to prevent rising mycotoxin levels.
Early detection of microbial risk can guide procedures and inform tailor-made solutions to address specific needs, depending on the local situation and conditions. A good sampling plan is crucial to establish the microbial risk and how to best mitigate those risks. By taking samples across the process at critical control points (CCP’s) and analysing them for microbiological load, challenges can be identified.
CCP’s are specific places along the production process where there could be a high risk for microbial contamination. The first one being the raw material intake pit. Different kinds of raw materials from different sources and quality levels enter the feed process. Cross contamination can easily occur during this step, so it is very important to monitor this closely.
As condensation is a major risk factor, due to the rapid increase of free water, any place where this occurs is a CCP. Usually, condensation occurs when hot material undergoes a sudden drop in temperature. Such thermal conditions can occur when feed leaves the pelletizer, when feed or feed ingredients move through the drying stage, and inside coolers at a feed mill or at oilseed crushers after the DT/DC (heating and cooling step in the oilseed crushing process). Furthermore, locations that are difficult to clean could harbour biofilm, which is a slimy layer formed by microorganisms like bacteria and fungi providing them protection and enabling them to thrive on surfaces. Examples of this could be a dead-end at a screw conveyor, bucket elevators, or even mixers that are sometimes neglected because of continuous production.
Common sense tends to be key when identifying CCPs in the plant. Seeing and feeling where the condensation might occur, and smelling can help identify mouldy or wet products in a certain area. All senses can help with speedy identification, allowing processors to act accordingly.
When sampling, it is recommended to wear sterilised gloves to prevent cross contamination. Plastic Ziploc bags help secure the material when taking samples of dust, raw materials, final products, or compound feed. And, as microbes can proliferate fast, it is important to get the samples to the lab as quickly as possible for the most accurate analysis. In addition to taking material samples, moist sponge swabs can be used to wipe surfaces that are identified as critical control points. They have a bigger surface than the normal cotton bud swabs, providing a bigger area to sample. Swabs can only identify the presence of bacteria, not the quantity, but offer a rapid way of alerting to a potential issue, so that immediate actions can be taken.
TECHNICAL APPLICATION
A big part of the three-pillar approach is to address the challenges faced by applying specialty formulated blends of organic acids. These carefully selected blends of buffered and non-buffered organic acids provide a strong reduction factor and allow for slower release of active ingredients over a period of time.
Selko offers two specific product brands that are specially formulated to address various microbial risks. Fylax, in the case of mould inhibition and Fysal when it comes to enterobacteria, like Salmonella, control. Whether it be treating grains or complete feeds, Fylax and Fysal have demonstrated proven efficacy for decades. Figures 1 and 2 provide examples of how effective these products are against microbial risks:
*100 cfu/g is the minimum detection limit for analysis of mould counts. All the 14-day results showed <100 cfu/g.
A critical factor in these solutions is the application method of treatment products. Contact point and distribution are very important to ensure sufficient dispersion through the raw materials or feed. Safety is always top priority so making sure that the organic acids are applied safely is one of the differentiating factors. When it comes to different flow rates of conveyors, varying mixers sizes or harbour treatment, Selko has a solution that is tailor-made to the situation. Dosing equipment is seen as a major part of the service offering and special care is taken to generate a needs-driven solution.
MANAGEMENT
Controlling microbial challenges in feed and feed ingredients requires a consistent approach and is most effective when incorporated in standard company protocols. Establishing hygiene management practices help stay on top of challenges that might arise.
Measuring and analysing samples from CCP’s on a weekly basis is a good start. This will assist to act proactively and accurately. Taking bigger sample sizes can help to identify potential risks in a more effective way. Increasing sample sizes to 1.5 kilogram, which the lab can split into 6 x 25 grams samples, provides a more representative picture of the situation.
Regular sampling and analysis help guide the most effective combination of preserving, or treating, ingredients against microorganisms. And effective application through safe and accurate dosing equipment, ensures the optimal mixing and dispersion of treatment products for maximum return on investment.
IN CONCLUSION
Microbial risks, particularly from moulds and gram-negative bacteria, like Salmonella, pose significant challenges in food processing, with raw materials and varying temperatures and moisture levels creating optimal environments for growth. Early detection through comprehensive sampling plans at critical control points is essential for implementing tailored solutions. These critical points include raw material intake pits and areas where temperature differentials create condensation, fostering microbial growth.
Effective sampling using the correct methods, tools and equipment will assist in effective and accurate analysis. Addressing these challenges often involves applying specialty formulated blends of organic acids, such as Selko’s Fylax and Fysal, tailored to specific microbial risks.
Appropriate application methods and dosing equipment are crucial for ensuring the safe and effective dispersion of these products. Consistent control through holistic approaches, including management practices and regular measurement and analysis at critical control points, is vital for proactive mitigation.
Selko focuses on a solution driven approach that will assist with a comprehensive sampling plan incorporating feed safety audit and analysing the samples for microbial risks. Secondly, choosing the correct product and application according to the type of microorganisms present and through tailor-made dosing equipment applying these products in the safest and most effective way. This process is always supported by knowledge transfer and assistance in the processes to ensure a proactive approach. Selko offers services such as a raw material analysis kit that helps identify CCP’s and taking representative samples to create a current microbial blueprint.
About Pieter Steyn
Pieter Steyn is Selko’s commercial technical manager for the Raw Material Quality Programme. In his current position he provides technical and commercial support to internal teams, as well as customers around the globe. He has a passion for safe feed production, with a focus on feed ingredients and raw materials.
Originally from South Africa, Steyn gained his experience through various sales- and technical positions within the agricultural industry in that region. For the past three years he’s residing in the Netherlands and has in traveling around the world, shared and expanded his knowledge and experience in effective grain preservation.
