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Antimicrobial Control

Precautionary Measures to Prevent Salmonella Contamination

The health of production animals is just as important for the consumers as it is for the farm itself.

Pathogens include bacteria, viruses or other microorganisms that can cause diseases in humans and/or animals.

Bacteria can be transmitted from feed to animals and through the animal products to humans. Some of the illnesses that it can cause include food poisoning/Salmonellosis, typhoid or para-typhoid fever.

Contamination can take place at any point.

Feed mills are for example at risk of contamination from various environmental sources, such as raw materials supplied from external parties and regions with unknown contamination levels and risks.

Precautionary measures for feed ingredients, surfaces and feed is a common method to control pathogens.

Feed Raw Materials

It is crucial to effectively control Salmonella contamination as early as possible in the feed chain. Feed raw materials are processed, handled and transported multiple times before use, which intensifies the environmental contamination of these products.

Oilseeds at the Extraction Plant

The processing of oil seeds generates a lot of dust and heat. Dusty, warm and humid conditions in the extraction plant are very suitable, not only for Salmonella survival, but also for the rapid multiplication of Salmonella. Storage conditions often favour post-production contamination of oilseed by-products.

Seaports and Other Reception/Destination Points

Imported oilseed meal and fish meal are frequent sources of contamination.

Compound feed Salmonella contamination

Contamination of compound feed by Salmonella is not uncommon, even in feed that has undergone heat treatment. Re-contamination after heat treatment may occur at any stage after heat treatment (such as cooling, conveyance and transport) as the heat-treatment cannot provide any residual effects.

Salmonella contamination in feed transport vehicles

All vehicles used for transporting incoming raw materials and compound feeds must be subjected to regular cleaning and sanitising programmes to ensure hygiene at all times.

Salmonella contamination inside silos

Condensation, wild birds, insects and rodents produce an environment capable of supporting growth of Salmonella and other pathogenic bacteria inside silos. For this reason, effective control measures are important to prevent contamination in silos.

Feed Mill Salmonella Contamination

Surveys of the prevalence of pathogens in the feed chain have shown high Salmonella prevalence in dust samples from pre-heat and post-heat areas of the mill, as well as inside the pellet cooling systems.

Prevalence of Salmonella infection in animal populations

The presence of Salmonella in animal populations is considered a risk factor for the presence of Salmonella in meat and eggs. The basis of successful control of Salmonella infections in animal farms is good farming and hygiene practice, as well as regular testing and treatment of positive flocks. Interventions to keep a low prevalence of Salmonella is critical.

Salmonella contamination from the environment

Major sources of Salmonella contamination in the environment are cooling air, dust, equipment, condensation, wild birds and rodents. Persistent environmental contamination has been shown to be a major factor in the infection of feed and flocks.

Re-contamination on farm-level

Should the necessary preventative measures and health and safety protocols not be in place, the farm’s environment can re-contaminate feed, water and animals with Salmonella. Biosecurity programmes that deal with multiple threats should be implemented on farm-level.

Salmonella contamination of carcasses during the slaughter process

The slaughter process has an impact on the risk of carcass contamination. During processing Salmonella may be transferred to carcasses from certain sources. The most important is infection in the batch of animals being slaughtered. The second source of contamination is between a positive batch of animals and subsequent carcasses from negative batches (cross-contamination). Control measures should be implemented to ensure management of these risks.