Salmonella problems can occur in all segments of the poultry feed chain. Infection may happen during the production of feed materials all the way up to the production of live animals. With its “Food Safety initiative” Kemin AgriFoods supports the poultry industry to win the battle against Salmonella.
By Luis Conchello, Kemin AgriFoods, Belgium
Salmonella is an important cause of foodborne disease in humans throughout the world and is a significant cause of morbidity, mortality and economic loss. Eggs and poultry meat are major sources of human food-borne Salmonellosis throughout the world. In the European Union microbiological criteria for Salmonella have been clearly established in different EU documents and regulations for feed raw materials, compound feed, the environment, animal populations, carcasses and fresh meat.
Kemin Food Safety initiative (FSi)
For an effective Salmonella control throughout the whole feed chain from production of feed up to the production of live animals at farm level, Kemin AgriFoods offers a complete and customer-designed “Food Safety initiative” (FSi) programme including all the necessary support. It includes an appropriate treatment of feed ingredients, finished compound feed, environment, drinking water, and animal populations with Kemin products such as Sal CURB® and FormaXOLTM at suitable concentrations, which is effective in controlling contamination by Salmonella spp. and other pathogenic organisms. The FSi preventive actions start at the level of oil-seeds and extraction plants. The importance of starting the control of Salmonella early at the extraction and the rendering plants must be emphasised in contrast to the current practice of focusing only on the feed mills.
Other important control steps need to be taken at farm level. Dust, compound feed, drinking water, and the Salmonella shedding prevalence in manure should be monitored. An effective support programme encompassing laboratory analysis, engineering work, and technical consultancy will provide adaptable solutions. These benefits are fully available to Kemin customers.
Control in feed and water
Processing of oil seeds generates a lot of dust and heat. Heat production especially during the winter season forms condensation. Dusty, warm and humid conditions in the extraction plant are very suitable not only for Salmonella survival but also for its rapid multiplication. That way Salmonella can be resident in an extraction plant with consequent infection of the final product through contaminated dust during various steps of the production process.
Oilseed meals such as rapeseed, soybean and sunflower meals, beans, and fish meal are major sources of Salmonella contamination in feeds. This makes contamination of compounded feed by Salmonella common even in feeds that have undergone heat treatment. The control of Salmonella also includes interventions to supply only Salmonella-free water. Drinking water hygiene is very important as part of a total bio-security programme at farm level. Indeed drinking water quality is as important as purchasing safe feed. Long term studies demonstrate that methods are available and in use on an industrial scale for the production of Salmonella-free feed materials as well as compound feed in spite of an often relatively high initial Salmonella contamination. The application of Sal CURB to combat bacterial pathogens in animal feeds and drinking water has been a well-established worldwide practice for many years.
Control in animals
The presence of Salmonella in poultry populations is considered as a risk factor for the presence of Salmonella in meat and eggs. There is a good correlation between the Salmonella broiler/ turkey flock prevalence and the prevalence of Salmonella-contaminated broiler carcasses. Lower broiler/turkey flock Salmonella prevalence will translate into lower prevalence of Salmonella-contaminated carcasses. In egg production there is as well a linear relationship between the flock prevalence and the number of eggs contaminated with Salmonella enteritidis. FormaXOL treatment of turkey/broiler/ laying hen flocks is regarded as an effective measure to decrease the shedding and prevalence of Salmonella in poultry populations because of its beneficial effect on the balance of commensal intestinal organisms. The product can be used in programmes associated with the higher prevalence and/or risk of Salmonella infection. It gradually reduces the percentage of positive flocks in order to reach an acceptable level. From then on, a preventive FormaXOL programme will keep the safety level under control.
This protective effect is very useful, firstly by reducing the high prevalence of Salmonella infection in high risk conditions. Secondly it has a preventive action to maintain a Salmonellafree status.
Persistent environmental contamination has been shown to be a major factor in the infection of poultry flocks. All vehicles used for the transport of incoming raw materials and compound feedingstuffs must be subject to regular cleaning and sanitising programmes ensuring that they are in a clean state. Several studies have pointed out the possibility of condensation in ingredient storage containers producing an environment capable of supporting growth of Salmonella. Flat stores are attractive to wild birds and rodents and for that reason effective control measures are important to prevent contamination. It is important that silos are cleaned regularly as well as flat storage areas. Surveys of the prevalence in the feed chain have shown high Salmonella levels detected in dust samples from the preand post-heating treatment area of the feed mill, as well as inside the pellet cooling systems. Recontamination of feed by feed bacterial pathogens through cleaning and disinfecting unsanitary equipment surfaces and dust that are in contact with feed can be prevented by using Sal CURB dry, which is user-friendly and should be applied with Kemin Dusters at the recommended dose rate. The farm environment can re-contaminate feed, water, and contaminates animals.
The risk is increased in cases of insufficient cleaning/disinfecting of silos, equipment and feeding systems. It is therefore important to implement a biosecurity program which deals with multiple threats. These threats include: people and visitors, vehicles, wild birds and wildlife in general, pest, vermin, lizards, insects, bedding materials, water supply, feed, tools and equipment, dust, surfaces, perimeter fences and gates.
The slaughter process has an impact on the risk of carcass contamination. Salmonella may be transferred to carcasses during processing from three major sources. The most important is infection in the batch of birds being slaughtered.
The second source of contamination is between a positive batch of birds and subsequent carcasses from negative batches (cross contamination). The third category of contamination is caused by the establishment of resident populations of Salmonella in biofilms associated with the processing equipment, environment and recycled water supplies. In this case the original introduction of contamination on infected birds may have been months or years previously but has then persisted due to inefficient initial disinfection. Once inaccessible biofilms have formed they can be extremely difficult to eliminate. Effective slaughter hygiene procedures and other interventions should be in place keeping in mind that Salmonella can grow in the slaughterhouse environment.
Salmonellosis in humans
Salmonellosis can range from a mild to severe gastroenteritis and in some people, to an invasive disease, which can be fatal. Long term consequences such as reactive arthritis can also result from Salmonella infections.
The EU27 member states have no less than 1 million and possibly as high as 15 million cases of clinical Salmonellosis per year. This Salmonella caused disease costs between €2-3 billion per year in the EU. The most important public health aspect of Salmonella dissemination is through the contamination of eggs. The vast majority of the Salmonellosis outbreaks that reported to have resulted in death were also attributed to eggs. In the EU, two serovars, Salmonella enteritidis and Salmonella typhimurium are considered of paramount public health significance. Together, they account for approximately 80% of all human isolates with S. enteritidis being the most important. Other serovars do not individually exceed 1%.
• Salmonella is an important cause of foodborne disease in humans throughout the world and is a significant cause of morbidity, mortality and economic loss.
• Eggs and poultry meat is a major source of human foodborne Salmonellosis in the European Union and throughout the world. • T he presence of Salmonella in poultry populations is considered as a risk factor for the presence of Salmonella in meat and eggs.
• Animals can become infected from contaminated feed, drinking water, and the environment. There is increased susceptibility to Salmonella infection in young animals and in those under digestive stress, production stress or suffering from disease. Animals may also become directly infected from other Salmonella-infected animals.
• Transmission of Salmonella from animal feed to animals consuming the feed, and to food products derived from the animals has been shown.
• Oil seed meals and fish deri ved proteins are the major risk feed materials for introducing Salmonella contamination to EU feed mills and industrial compound feed.
• It is important to start the Salmonella control programme already at the earliest stage possible such as in the extraction and rendering plants.
• Establishment of microbiological criteria at several critical stages along the Poultry Feed Chain to ensure absence of Salmonella contamination is crucial.
• For an effective Salmonella control through the Poultry Feed Chain, Kemin AgriFoods offers the “FSi” programme, which is a complete and customer-designed programme including all the necessary support.
• The Kemin “Food Safety initiative” involves interventions in feed raw materials production including extraction and rendering plants, feed mills, finished feed, drinking water, animal populations, storage facilities, farms, means of transport and the environment.
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