Clean feed promotes feed safety

There is ample evidence in published research work showing that feed is a fomite for bacterial and viral pathogens. A growing body of literature, due to increased awareness and novel technologies such as CRISPR, has linked Salmonella, Clostridia, E. coli, Campylobacter, Avian Influenza and African Swine Fever to feed and feed ingredients.

Feed is an integral part of animal production with a direct, measurable impact on animal performance, health and welfare, productivity and operational profitability. Feed quality from the nutritional and microbiological standpoints and the presence of specific feed-source pathogens such as Salmonella negatively impact the value and safety of feed and feed ingredients.

FEED-SOURCE PATHOGENS IMPACT FEED AND FOOD SAFETY
Bacterial pathogens such as Salmonella and E. coli, both members of the Enterobacteriaceae family, are commonly isolated from feed and raw materials. Bacterial feed-source pathogen prevalence varies depending on the material type, source and harvest seasonality of the ingredients used in finished feed formulations. Microbial contamination type and load are also influenced by storage, transport and production environments. Feed-source pathogens are ingested by livestock, and this challenge may compromise gut integrity and microbial balance by displacing good commensal bacteria which contribute to efficient digestion and intestinal health. In extreme cases, these pathogens do irrecoverable damage to the gut lining and inhibit the animal’s long-term ability to derive nutrients from feed. In addition, pathogen activity in the gut can trigger inflammatory processes and lead to an innate immune response, resulting in the animal spending energy, typically used to produce meat and eggs, to manage incoming pathogens.

Matt Oldnall, Anitox Technical Services Manager for EMEA and AP, explains: “Feed is the most significant investment into animal production, and a proven fomite for pathogens such as Salmonella, Clostridia, E. coli and Campylobacter. These negatively impact animal production, operation profitability and food safety.”

In contrast to other fomites, feed is central and widespread within all animal production systems. Everything from trucks, milling equipment, people and feeder lines come in direct contact with feed and feed ingredients sourced globally from various climates, growing seasons and potential microbial loads. Repeated exposure to these secondary fomites increases the risk of contaminating subsequent feed batches and increasing pathogen prevalence within the feed and food production chain.

“Research has shown that feed microbial loads host various feed-sources pathogens at variable levels, making it critical for feed and food producers to have effective feed pathogen control tools. For example, experiments using CRISPR-based technology found that feed can harbor diverse populations of Salmonella, including multiple serovars. Furthermore, it revealed that nearly 6% of tested samples collected from over 130 commercial mills were positive for Salmonella. Throughout the body of literature, studies conclude that Salmonella prevalence in feed and feed production facilities varies but persists from ingredient reception to loadout. Failure to mitigate feed-source pathogens preludes facility contamination, subsequently leading to recontamination of feed within the production process,” says Oldnall.

Bacterial pathogens such as Salmonella are naturally occurring in the environment and are capable of surviving in feed. Mills and live production can create a suitable environment to allow bacterial proliferation and survival in feed and can lead to the contamination of feed mill machinery, trucks and other areas associated with the feed production process, creating the perfect opportunity for further contamination or recontamination of feed. Feed mills usually have maintenance and hygiene protocols to prevent pathogen transmission to and within feed production, yet many of these processes and requirements lead to additional ingredient processing, limited throughput and productivity, extra downtime and costs due to decontamination procedures.

“Viruses such as Avian Influenza (AI), African Swine Fever (ASFV), Porcine Epidemic Diarrhea virus (PEDV) and Porcine Reproductive and Respiratory Syndrome (PRRS) are all part of the evidential body examining feed and feed ingredients as a transmission route,” says Oldnall. “Major findings include trials by Dr. Toro at Auburn University College of Veterinary Medicine determining that AI can survive in a feed matrix, especially when feed is further contaminated with organic matter, such as feces. In addition, several peer-reviewed studies have evaluated the survival of swine viruses in animal feed and feed ingredients, confirming that viruses survive in feed matrices and identifying specific ingredients that appear to enhance virus survival. Feed and feed ingredients are an infectious vehicle for bacterial and viral pathogens and a credible risk to biosecurity. This work suggests that repeated exposure of feed and feed-source pathogens to livestock increases the likelihood of a minimum pathogen load being required for viral and bacterial infection.”

“As a fomite, feed significantly impacts animal production, performance and welfare, largely due to the numerous ways feed and feed ingredients become contaminated with pathogens. Every operation, raw material and feed formulation has different needs and challenges.” Oldnall continues, “Contaminated feed can reach multiple houses and barns within a single operation, extending its influence across an entire operation. It is more common to see a disease start with a single subset of animals and then observe it spreading horizontally through animals in close contact. When we see disease resulting from feed-source pathogens, we see a more immediate distribution throughout the operation.”

FEED PATHOGEN CONTROL PROGRAMS EFFECTIVELY MITIGATE FEED-SOURCE PATHOGENS
Clean feed is an effective tool within a comprehensive biosecurity program designed to prevent disease. Mitigating feed-source pathogens and successfully achieving animal performance and productivity goals require reduced microbial loads and pathogen prevalence in feed and feed ingredients. Producing and utilizing clean feed with fewer feed-source pathogens, spoilage organisms and a lower microbial load equip feed and food producers in achieving operational performance and productivity goals.

Feed sanitizers and organic acids blends are commonly used to mitigate enteric pathogens. Producers rely on them to mitigate feed-source pathogens and reduce incoming challenges at the source, ultimately maximizing the nutritional value of feed.

Organic acids are efficient at acidifying feed, creating a hostile environment for bacterial pathogens including Salmonella and E. coli, and reducing the pathogenic load of raw materials and finished feeds. Organic acid-based solutions that remain in the feed post-pelleting work by reducing the pH in the digestive system, making it a less conducive environment for pathogenic bacteria, eventually leading to bacterial cell death.

Some organic acids blends such as Fortrol®, Anitox’s latest specially formulated feed pathogen control solution, reduce feed-source pathogen transmission and lowers the microbial load of feed following pelleting and processing.

Oldnall explains, “Managing feed as a fomite and achieving animal performance and productivity goals require implementing effective feed pathogen control that reduces the microbial loads and pathogen prevalence found in feed and feed ingredients. The variable risk associated with feed and feed ingredients demands solutions that allow producers to manage their specific risks. Whether applied to feed and feed ingredients on a routine basis, as a corrective treatment for Salmonella-positive feed material or used to flush mills and ingredient processing facilities, Fortrol® enables producers to protect feed value and mitigate risk. It can be used flexibly and independently at various inclusion rates or in combination with a feed sanitizer such as Finio®.”

Feed sanitation requires using bactericidal compounds at low inclusion rates to control microbial contamination and offer long-lasting protection against feed recontamination. Feed sanitizers have been repeatedly shown to effectively reduce Salmonella contamination in feed. For example, a study performed by the Animal Plant and Health Agency (APHA) determined that a formaldehyde-free feed sanitizer controlled Salmonella in feed at 1 kg/MT.

“Our primary goal is to aid producers in developing a cost-effective, challenge-dependent, comprehensive Salmonella control strategy. Feed sanitizers are effective and protect against recontamination, ensure clean feed moves throughout feed production, remaining pathogen-free until the point of consumption and are the only effective option for producers facing significant feed-source pathogen challenges and requiring long-term protection,” adds Oldnall.

Implementing an effective feed pathogen control program that utilizes feed pathogen control tools suited to your specific risk protects feed and food safety while strengthening biosecurity within live production and improving animal performance.

*Author
About Dr. Enrique Montiel
Veterinarian, Dr. Enrique Montiel has more than 25 years global poultry and animal health experience. A Master of Science in avian pathology and immunology and a Ph.D. in poultry science, he is a leading authority on the influence of feeding methods on immune responses in poultry. As Global Director of Nutrition and Live Production at Anitox, Dr. Montiel supports global understanding of feed as a fomite for performance-limiting pathogens including Salmonella and viruses, and works closely with the world’s leading producers to prevent feed-source pathogens entering live production.

**Article Contributor
About Matt Oldnall
Matt Oldnall has over 10 years of experience in the poultry industry. Following his completion of a Bachelor of Animal Science and subsequent Honours in Poultry Science at the University of Pretoria, he went on to further his education with a specific focus on feed and feed pathogen control during his Master of Science in Poultry Production at Harper Adams University. As Technical Services Manager for the EMEA and AP, Matt aids producers in understanding feed as a fomite and works alongside leading producers to implement effective feed-source pathogen mitigation strategies.