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Organic standards and food safety
The
most relevant regulations of the standards in relation to food safety are the
requirements to feed
100% organic feedstuffs and prolonging withdrawal periods
following the use of with chemically synthesised veterinary medicinal products.
It is assumed that these requirements reduce chemical residues in organic
livestock products. However, even the prolonged withdrawal period cannot
guarantee absolute absence of chemical residues. Further, food safety is not
only characterised by the absence of residuals but is related to many hazardous
risks for human health (e.g. zoonoses) that are not covered by the standards (Walkenhurst
and Sundrum, 2003).
A new zoonosis directive was adopted in 2003 that updates and expands the Regulation 92/117/EEC. All EU countries have established national food safety programmes that include, in the first phase, a comprehensive monitoring of relevant food chains for important zoonotic, food-borne pathogens at points where the contamination most probably takes place, as well as monitoring systems for human infectious diseases associated with food-borne transmission (Hänninen, 2005).
Hazard Analysis and Critical Control Points (HACCP)
Hazard Analysis and Critical Control Points (HACCP) is a systematic preventive approach to food safety and pharmaceutical safety that addresses physical, chemical, and biological hazards as a means of prevention rather than finished product inspection. HACCP is used in the food industry to identify potential food safety hazards, so that key actions, known as Critical Control Points (CCP's) can be taken to reduce or eliminate the risk of the hazards being realized. The system is used at all stages of food production and preparation processes including packaging, distribution, etc (from Wikipedia).
Critical Control Point (CCP) is a point, step or procedure at which controls can be applied and a food safety hazard can be prevented, eliminated or reduced to acceptable (critical) levels.
The Organic HACCP project is an EU-wide project using consumer concerns as the main criteria of assessment to provide recommendations to participants on the chain of production, distribution and consumption with regard to improving the safety and quality of certified organic food products. The project has produced a series of information leaflets, two of which are of particular relevance to organic livestock producers:
– Milk Production Control of Quality and Safety in Organic Production Chains (Bergamo et al., 2005)
– Egg Production and Packaging Control of Quality and Safety in Organic Production Chains (Ogden et al, 2005)
The EU project Sustaining Animal Health and Food Safety in Organic Farming (SAFO) had the objective of improving food safety and animal health in organic livestock production systems through exchange and active communication of research results and conclusions between researchers, policy makers, farmers and the wider stakeholder community, including consumers. Numerous papers on a range of related topics can be found at http://www.safonetwork.org.
Animal health security, the role of zoonotic diseases and the risk of environmental contaminants in organic livestock produce are presented in the proceedings of the 3rd SAFO meeting . Allowing livestock access to outdoors is a fundamental principle in organic farming. Such access is seen as part of the animal’s freedom to natural behaviour and can be argued to offer substantial health benefits to animals. Outdoor access, however, also allows access to potential environmental contaminants, contact with other livestock or wildlife with different disease status and with vectors and fomites that may be carriers of zoonotic diseases. Papers were presented on the level of toxoplasmosis in organic pigs (Mul, 2005), paratuberculosis in organic cattle (Kijlstra, 2005a) and campylobacterial carriage in organic layers (Hänninen, 2005). Mycotoxin (Lorenzini et al., 2005) and dioxin contamination (Kijlstra, 2005b) of organic livestock produce and the control of heavy metal contamination in organic systems (Schumacher, 2005) were also discussed. Outputs from the workshop suggest that the link between higher risk for zoonoses and environmental contamination and outdoor access and other organic management practices is not a straightforward one and that the risks are not necessarily greater in organic systems. However, it is clear that monitoring of zoonoses and contaminants is just as important in the organic as in the conventional animal production context.
The most important food-borne, bacterial illnesses in Europe are campylobacteriosis, caused mostly by Campylobacter jejuni, and salmonellosis, caused by several salmonella serovars (Salmonella enterica serovar, enteritidis, typhimurium and some other less common serovars) (Hänninen, 2005). As poultry flocks are easily contaminated by campylobacters from several potential sources during the rearing period, a high level of biosecurity is required for prevention of contamination. The high susceptibility of poultry flocks from campylobacter contamination is reflected in the high number of campylobacter positive flocks reported in several European countries: 50 to 100% of the flocks are positive (Hänninen, 2005).
There are specific
risks associated with organic and free-range systems that make these systems
potentially more susceptible to contamination by zoonotic enteric bacteria,
such as campylobacters or salmonellas. Organic laying birds have free access to
the outside environment and hence more exposed to contamination.
Additionally, the life span of organic table birds is significantly longer than
in conventionally managed flocks.
In case of , the is due to infection in the oviducts and ovaria of hens. Prevention of S. Enteritidis contamination is targeted on the spread of infection to farm by high level of biosecurity and vaccination of birds, to increase their immune response. Other salmonellas, e.g. S. Typhimurium, contaminate the shells of the eggs by faecal material after laying. Prevention is targeted to biosecurity and handling eggs at farm.
Similarly, the food safety aspect associated with campylobacter colonization in hens is faecal contamination of egg shells. The survival characteristics of salmonellas and campylobacters are, however, not similar. Salmonellas resist dryn and ambient temperature much better than campylobacters and hence have more opportunities to survive the egg food chain.
Toxoplasma gondii is a ubiquitous protozoan parasite capable of infecting all warm-blooded animals (Tenter, 2000) and, following salmonellosis and listeriosis, toxoplasmosis has been shown to be the third major cause of food related deaths (Mead et al, 1999). In the past, the consumption of raw or undercooked meat, in particular of pigs and sheep, has been regarded as a major route of transmission to humans. Although recent studies show that the prevalence of T. gondii in meat-producing animals decreased considerably over the past 20 years in areas with intensive farm management (Tenter, 2000) there has been a suggestion that animal-friendly production systems may lead to a re-emergence of Toxoplasma infections (Kijlstra et al., 2004). A study in the UK suggested that a significant proportion of commercially available meats were contaminated with T. gondii. (Aspinall et al., 2002). A Dutch study showed that whilst all conventional pigs surveyed at slaughter were negative, a small percentage of organic or free-range pigs tested positive although many of these farms remain Toxoplasma free (Kijlstra et al., 2004). The authors recommend abattoir monitoring of pigs from free range systems combined with on-farm prevention strategies.
The presence of cats on a farm is an important risk factor. Kijlstra (2005b) report the mean number of cats on organic and free range pig farms as being 4.9 and 6.3 compared with a mean of 2.2 on conventional farms. Rats and inadequate rodent control is also a risk factor Kijlstra (2005b) also describes the use of chemical rodenticides on all surveyed conventional farms compared with 31% of organic and 14% of free-range farms that do not use chemical control. Rodents can form a reservoir of toxoplasma that can be very difficult to control (Owen and Trees, 1998). Since cats are an important source of oocysts, and keeping pigs outdoors is a pre-requisite for organic production, Kijlstra et al. (2004) view the control of cat populations coupled with vaccination as the most important control strategy on organic farms. Cats should not be allowed to have access to the outdoor area, feed, roughage supply, bedding materials and pig housing. Cats should not be used as a method of rodent control. Pigs should not be presented with an opportunity to eat a dead or live rodent. Additionally pigs should only have access to a water supply that is free from toxoplasma oocysts Development of a hazard analysis critical control point (HACCP) system in combination with serologic monitoring at slaughter should lead to the implementation of strategies to prevent toxoplasma infection of pigs raised in conditions that improve their welfare i.e. outdoor production (Kijlstra, 2005b).
For more information on rodent control see:
Rural Development Service Technical Advice Note 35 Rats: Control on Livestock Units,
Technical Advice Note 34 Rats: options for controlling infestations,
Central Science Laboratory Factsheets The control of rats with rodenticides - a complete guide to best practice and
Mycotoxins are toxic secondary metabolites produced by mould fungi, which in high amounts can damage kidneys or immune systems of animals and humans. Mycotoxins can be formed in growing plants and the fungi can continue to develop after harvest. Mycotoxins from contaminated feed can pass through the animals and occur in small amounts in meat, eggs, and milk.
The most important Critical Control Point (CCP) for mycotoxin production in the field is the maintenance of several measures of good agricultural practices. The harvest of grain constitutes a very important CCP as the timing of the harvest and moisture of the grain have a major impact on the level of later fungal growth and mycotoxin production. For mycotoxin production in storage, inappropriate conditions of storage of organic grain, flour and silage maintenance are also an important CCP. To ensure that the farmer, wholesaler or processor prevents or reduces further growth of moulds and mycotoxins, accordingly, conditions need to be adjusted to the product in storage, feed and foodstuff needs to be checked regularly for visible signs or smells of mould growth and an appropriate quality assurance system needs to be in place (e.g. sampling plans when and where) (Wyss, undated extracted from www.organichaccp.org).
See also Mycotoxin pages.
Abiotic contaminants of livestock feed
Abiotic contaminants comprises agricultural pesticides and heavy metals. A pesticide, usually chemical but also biological, is used to control, to repel, to attract or to kill pests, for example, insects, weeds, birds, mammals, fish, or microbes, that are considered a nuisance. Inevitably, the absence of residual pesticides in organic farming practice would suggest that pesticide levels in organic food are going to be significantly lower than food produced in systems that rely on chemical inputs. Pesticides may occur in low levels on organic foods but in amounts harmless to humans (Wyss, undated extracted from www.organichaccp.org).
A Guide to Food Hygiene and Other Regulations for the UK Meat Industry is produced by the Food Standards Agency