The Importance of Hazard Analysis by Critical Control Point for Effective Pathogen Control in Animal Feed: Assessment of Salmonella Control in Feed Production in Sweden, 1982–2005

This study is the first to show that Hazard Analysis by Critical Control Point (HACCP)-based monitoring can be an effective tool for ensuring Salmonella-safe feed, by virtually eliminating feedborne Salmonella infection even in broiler production. Data from the control of Salmonella in feed and food animal production during 1982–2005, showed that conventional endpoint testing in feed mills did not ensure a Salmonella-safe feed, and in one feed mill failed to detect Salmonella contamination, resulting in the feed infecting 80 out of 197 (40.6%) recipient broiler flocks. Following implementation in 1991 of a HACCP-based control in feed mills, the annual number of samples tested at specified critical control points during a 15-year period increased from ∼4400 to 10,000, while the proportion of Salmonella-contaminated samples decreased from 2.0% to 0.3%. Thus, introduction of HACCP was followed by a dramatic decrease, from 40 to Salmonella-infected broiler flocks identified by preslaughter monitoring. Incidence has generally remained at that low level, despite production since 1980 increasing from 39 to 112 million chickens per year. Feed mills start using soymeal with an unsafe Salmonella status and possibly with a suboptimal HACCP control, increased their level of Salmonella-contaminated HACCP samples, and their feed subsequently infected 78 swine-producing herds. The results also show that the HACCP concept can be an effective tool to supply feed mills with Salmonella-safe feed ingredients as demonstrated for a soybean crushing plant, which produced Salmonella-safe soymeal over a 19-year period despite frequent (34%) and highly varied (92 different serovars) Salmonella contamination in samples from incoming soybean. Similar results are reported for a plant producing rapeseed meal. It is emphasized that the achievements described through use of the HACCP required interventions of relevant preventive biosecurity measures and corrective actions when the HACCP-based monitoring identified Salmonella contamination

Successful control of salmonella and a minimized use of antibiotics in Swedish broiler production by long term implementation of disease preventive methods with special reference to the use of competitive exclusion (CE)

The use of antimicrobials and the isolation of Salmonella are rare events in the Swedish broiler production. This is result of a long term implementation of disease preventive measures as alternatives to antibiotics for health management, in particular in the absence of antimicrobial growth promoters (banned 1986, Wierup 2001), and for the control of Salmonella. Apart from coccidiostats, antimicrobials, was e.g. in 2011 only used in 6 (0.02%) of 3185 commercial broiler flocks (approx.70 mill. birds) and during the last 16 years the average annual incidence of Salmonella infected flocks when tested before slaughter, was 0.2%, and 0.03% of Salmonella contaminated carcasses when tested after slaughter (Anon 2011). The control of Salmonella in food animals was initiated some 60 years ago due to severe Salmonella epidemics including one of world's largest known outbreaks, which 1953 involved more than 9000 sick and the death of 90 persons. Due to similar reasons producers 1970 initiated a specific control for broilers and since 1984 this is mandatory for all producers, who also pay its cost with the aid of insurance. Detailed rules for hygiene and management procedures and testing for Salmonella are formulated and highest demands apply to hatcheries (Anon 2011). Essential elements include prevention of introduction of Salmonella through feed and breeding animals as well as a high level of biosecurity at the farm level, and e.g. during 1982-1988 12 out of 39 (30.8%) flocks of broiler-GP to be imported was found to be Salmonella infected. Since 1972, all broiler feed must be heat treated. HACCP based controls are in place in all feed plants, and corrective actions taken whenever Salmonella is isolated in the weekly samples. Compliance is ensured by bacteriological testing of all flocks 2 weeks before slaughter intended to detect a flock prevalence of Salmonella infected birds of > 5%. If any Salmonella, irrespective of serotype, is detected the flock is destroyed. In addition meat products contaminated by any serovar of Salmonella are since 1971 declared unfit for human consumption. Antibiotic has never been used to control or eliminate Salmonella infections in poultry or other food animals. CE was used during a critical period for the buildup of the current favorable Salmonella status. CE-culture (Broilact®) was found to be a valuable tool in particular to avoid re infection in units where preceding flocks had been Salmonella infected and during periods when the probability for Salmonella contamination of feed was considered as high. During 1981-1990, CE-culture was thus given on arrival of the chicks of 179 flocks (3.82 mill. chickens) in their initial drinking water. Only one of the flocks was found to be Salmonella infected. The virtually Salmonella free status of the hatcheries in Sweden are assumed to be contributing to this good result. However, a specific assessment of the salmonella controlling effect during a period when Salmonella was spread by contaminated feed, demonstrated that the CE-culture had an effect also under these conditions (Wierup et al., 1988). During recent years the CE- culture has been administrated as a spray of chickens directly after hatch to prevent spread of possible Salmonella infection from breeders and interesting studies are underway to assess its possible effect for reducing the spread of Enterobacteriaceae with transmissible resistance against extended-spectrum cephalosporins. References Anon 2010, Surveillance of zoonotic and other animal disease agents in Sweden 2010, www.sva.se . Wierup et al 1998; Poult Sci. 1988 Jul;67(7):1026-33. Wierup 2001; Microb Drug Resist. 2001 Summer;7(2):183-90

Production of Soybean-Derived Feed Material Free from Salmonella Contamination: An Essential Food Safety Challenge

Soybean meal is the world\u27s most important source of protein for poultry and livestock. Due to frequent contamination of Salmonella, soy is since long unfortunately also found to be a high‐riskfeed material for the introduction of Salmonella to the animal food production. This chapter focuses on the importance of biosecurity and hygiene in the production of soy‐based animal feed. Those strategies and methods found to be effective tools for the production of a Salmonella‐safe soy feed material in crushing plants and feed mills are reviewed and presented. It is also shown that the implementation of those methods at a limited cost can prevent animal feed from being the weakest food safety link in the food chain

Nutritional strategies to combat Salmonella in mono-gastric food animal production

Nutritional strategies to minimize Salmonella in food animal production are one of the key components in producing safer food. The current European approach is to use a farm-to-fork strategy, where each sector must implement measures to minimize and reduce Salmonella contamination. In the pre-harvest phase, this means that all available tools need to be used such as implementation of biosecurity measures, control of Salmonella infections in animals at the farm as well as in transport and trade, optimal housing and management including cleaning, disinfection procedures as well as efforts to achieve Salmonella-free feed production. This paper describes some nutritional strategies that could be used in farm control programmes in the major mono-gastric food production animals: poultry and pigs. Initially, it is important to prevent the introduction of Salmonella onto the farm through Salmonella-contaminated feed and this risk is reduced through heat treatment and the use of organic acids and their salts and formaldehyde. Microbiological sampling and monitoring for Salmonella in the feed mills is required to minimize the introduction of Salmonella via feed onto the farm. In addition, feed withdrawal may create a stressful situation in animals, resulting in an increase in Salmonella shedding. Physical feed characteristics such as coarse-ground meal to pigs can delay gastric emptying, thereby increasing the acidity of the gut and thus reducing the possible prevalence of Salmonella. Coarse-ground grains and access to litter have also been shown to decrease Salmonella shedding in poultry. The feed can also modify the gastro-intestinal tract microflora and influence the immune system, which can minimize Salmonella colonization and shedding. Feed additives, such as organic acids, short-and medium-chain fatty acids, probiotics, including competitive exclusion cultures, prebiotics and certain specific carbohydrates, such as mannan-based compounds, egg proteins, essential oils and bacteriophages, have the potential to reduce Salmonella levels when added to the feed. These nutritional strategies could be evaluated and used in farm control programmes

Successful Prevention of Antimicrobial Resistance in Animals—A Retrospective Country Case Study of Sweden

The misuse and overuse of antibiotics have resulted in an alarmingly high prevalence of antimicrobial resistance (AMR) in human and animal bacteria. European monitoring programmes show that AMR occurrence in food animals is lower in Sweden than in most other EU Member States and that the use of antibiotics for animals is among the lowest in Europe. In this retrospective country case study, we analysed published documents to identify factors contributing to this favourable situation. A fundamental factor identified was early insight into and sustained awareness of the risks of AMR and the need for the prudent use of antibiotics. Early and continuous access to data on antibiotic use and AMR made it possible to focus activities on areas of concern. Another factor identified was the long-term control and eradication of infectious animal diseases, including coordinated activities against endemic diseases, which reduced the need to use antibiotics. Structures and strategies for that purpose established at the national level have since proven useful in counteracting AMR as an integral part of disease prevention and control, guided by a “prevention is better than cure” approach. A third factor identified was consensus among stakeholders on the need to address AMR and their cooperation in the design and implementation of measures

The cost-benefit of salmonella control in Swedish pigs

Analysis of the expected costs and benefits of salmonella control pre-harvest in the pork production has been performed on EU level (1). As optimal measures to begin salmonella control in pig production in a high prevalence situation are not known, estimates of the costs for initiating such a control include large uncertainties. However the costs for running a salmonella control program can be estimated in countries where such programs are in place. In Sweden, where approximately 3 million pigs are slaughtered yearly and the prevalence of salmonella is low, the cost of the control is shared by the tax payers and the producers

A Paleolithic diet confers higher insulin sensitivity, lower C-reactive protein and lower blood pressure than a cereal-based diet in domestic pigs

BACKGROUND: A Paleolithic diet has been suggested to be more in concordance with human evolutionary legacy than a cereal based diet. This might explain the lower incidence among hunter-gatherers of diseases of affluence such as type 2 diabetes, obesity and cardiovascular disease. The aim of this study was to experimentally study the long-term effect of a Paleolithic diet on risk factors for these diseases in domestic pigs. We examined glucose tolerance, post-challenge insulin response, plasma C-reactive protein and blood pressure after 15 months on Paleolithic diet in comparison with a cereal based swine feed. METHODS: Upon weaning twenty-four piglets were randomly allocated either to cereal based swine feed (Cereal group) or cereal free Paleolithic diet consisting of vegetables, fruit, meat and a small amount of tubers (Paleolithic group). At 17 months of age an intravenous glucose tolerance test was performed and pancreas specimens were collected for immunohistochemistry. Group comparisons of continuous variables were made by use of the t-test. P < 0.05 was chosen for statistical significance. Simple and multivariate correlations were evaluated by use of linear regression analysis. RESULTS: At the end of the study the Paleolithic group weighed 22% less and had 43% lower subcutaneous fat thickness at mid sternum. No significant difference was seen in fasting glucose between groups. Dynamic insulin sensitivity was significantly higher (p = 0.004) and the insulin response was significantly lower in the Paleolithic group (p = 0.001). The geometric mean of C-reactive protein was 82% lower (p = 0.0007) and intra-arterial diastolic blood pressure was 13% lower in the Paleolithic group (p = 0.007). In evaluations of multivariate correlations, diet emerged as the strongest explanatory variable for the variations in dynamic insulin sensitivity, insulin response, C-reactive protein and diastolic blood pressure when compared to other relevant variables such as weight and subcutaneous fat thickness at mid sternum. There was no obvious immunohistochemical difference in pancreatic islets between the groups, but leukocytes were clearly more frequent in sampled pancreas from the Cereal group. CONCLUSION: This study in domestic pigs suggests that a Paleolithic diet conferred higher insulin sensitivity, lower C-reactive protein and lower blood pressure when compared to a cereal based diet