The wild boar (Sus scrofa Linnaeus, 1758) is a large mammal belonging to the order Artiodactyla, family Suidae. Groves (1981) reported the existence of 16, possibly 17, subspecies of the genus Sus. According to Groves and Grubb (1993), the so called ‘Western races’ (S. s. scrofa and S. s. meridionalis) are known in Europe (Apollonio et al., 1988), S. s. algira in North Africa and S. s. lybicus in the Middle East extending at least as far east as Soviet Central Asia (S. s. attila and S. s. nigripes). The high sociality, reproductive potential, adaptability, sinantrophy, omnivory and other species specific features allow them adapting to different habitats. It is an adaptable species with a wide climatic tolerance. The Eurasian wild pig has one of the widest geographic distributions of all terrestrial mammals, and its range has been greatly expanded by human agency. Wild boar is widespread in most continental areas of Europe, and recently in Norway, with the exception of northern Fennoscandia and European Russia.
As a wild form, it has constituted a primary resource of subsistence hunters since the prehistorical times, and it is one of the most important targets for recreational hunting wherever it remains sufficiently or over abundant. Because its depredation on crops incurs a severe economic loss to communities, it is considered as a pest in many countries.
The main product is meat that represents the first source of game meat throughout Europe. The wild boar meat is largely consumed by the hunters and their families but a specialized market is developing in many countries. The main constraints to wild boar meat trade are the supply chain and the difficulty to fit the European regulation on food safety.
Although wild boar meat is considered safe and hygienically affordable due to its natural origin, the supply chain is often characterised by risks and critical points. Accordng to EFSA 2011, wild boar is a critical point when countries try to eradicate zoonotic diseases such as tuberculosis, brucellosis, yersiniosis and trichinellosis in humans, and important livestock infectious diseases such as pseudorabies and porcine circovirus-associated diseases (PCVADs) in pigs. At this purpose, proper handling of game meat from the field to the table and veterinary surveillance is extremely important.
As reported by Sales and Kotrba (2013) the microbiological quality of game meat will depend on: (1) microorganisms in the digestive tract and muscles of animals; (2) circumstances in which animals are killed; and (3) the conditions under which the carcasses are dressed. During storage of meat microflora development will be related to storage conditions and to biochemical characteristics of the meat (Gill, 2007).
Hygienic quality of game meat should be evaluated by both pathogenic bacteria presence and aerobic bacteria viable count (Avagnina et al., 2012). The aerobic bacteria viable count is usually higher in wild boar as compared to other wild species probably due to its habits (Avagnina et al., 2012). As no specific criteria are provided for wild animals’ meat the limit set by Regulation (EC) No 1441/2007 for meat from domestic animals (5 log cfu/cm2) is adopted.
It is interesting to highlight that aerobes and coliformes are lower in wild boar meat as compared to pork (Naya et al., 2003). This could be explained with the vacuum package storage of pork for extended periods, whereas wild boar meat was frozen or sold in a shorter time.
Also the location of a shot can affect bacteria contamination of muscle. Atanassova, Apelt, Reich, and Klein (2008) found values of 1.0–5.6 log10 cfu/cm2 for mesophilic aerobic plate counts and 1.7–3.5 log10 cfu/cm2 for the numbers of Enterobacteriaceae on muscles from different parts of wild boar. Higher values of counts were registered when the animals were shot at the digestive tract with carcass contaminated with faeces.
Studies performed by Avagnina et al., 2012 supported the hypothesis that lower aerobic viable counts and Enterobacteriaceae registered in chamois (Rupicapra rupicapra), roe deer and red deer hunted in the same region of wild boars were probably due to hunting methods (hiding vs. driven) or pre-slaughtering procedures.
According to Membré et al. (2011) Listeria monocytogenes is mainly related to meat processing contamination due to contaminated environment.
Another indicator of microbial quality is represented by Clostridium perfringes, mainly originating from the digestive tract and skin, indicating lack of hygiene during slaughtering and carcass handling.
The presence of nematode parasites as Trichinella spiralis in wild boar meat, have been reported from some countries in Europe, and North and South America (see Gill, 2007). Although the outbreaks of trichinellosis in humans, cooking wild boar meat until reaching a temperature of 77 °C (Greenbloom et al., 1997) is sufficient to inactivate this parasite. Despite plant material comprises near 90% in wild boar diet, they eat on animal matter including carrion and garbage available in the town neighbours. Thus, they could become infected if consume infectious cysts in raw meat.
Biosecurity measures for field dressing and meat inspection for Trichinella have been adopted in some EU countries (Latvia, Lithuania, Romania, Bulgaria and Slovakia ), where this infection have been detected in wild boar, and more in general in wildlife, even if the EU picture diverse.
As a general consideration Borilova et al., 2006 confirmed the importance of shooting that should be lethal and should avoid delay in bleeding, evisceration, chilling. These authors also confirmed that game meat has good microbiological and hygiene standard if storage regime, including temperature, is provided. However, due to rapid chemical changes of game meat, that play a role on the sensory parameters of the muscle, correct storage and temperature should be assured. These results deny the hypothesis about the short shelf life of game meat.
In a EU perspective the origin of the product, as to say traceability, because the possible uptake of contaminants is important due to the potential origin from polluted areas or local source of pollution. Heavy metals, elements that do not show an evident biochemical role, but could be toxic and accumulate in organs and tissue, such in tissues, such as cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), have been put in evidence in game meat or edible tissues above limits or passing tolerable intake. These limits (heavy metals) are passed in animals living close to mining sites or other pollution sources (Pokorny et al., 2009). This could be as a consequence of feeding on contaminated feeds, especially mushrooms or lichens (Reglero et al., 2008). Accumulation can increase with exposure (Falandysz et al., 2005). For some elements the higher accumulation capacity was registered in kidneys and skin, usually wasted, or liver that is sometime used for human consumption.
The health risk for meat consumers due to heavy metals is however considered negligible (Lazarus et al., 2008), and the contribution of heavy metals from wildlife has been decreasing in the last decades (Čelechovská et al., 2008).
On the other hand, the Pb contamination due to the residuals of bullets in the muscle area along the bullet pathway should not be neglected (Hunt et al., 2006). At this purpose it is necessary an accurate trimming of the carcass around wounds and bullet pathways (Doborowolska and Melosik, 2008).
Organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) are widely used in agricultural practices, and generally accumulate in fat of mammals (Guruge et al., 2004). These organic compounds are related to different toxic effects, are considered are endocrine disruptors and inducing cancerogenesis (Campbell and Campbell, 2001). Although PCB legal limits (Regulation (EC) 1881/2006 European Commission, 2006) in meat and offal of wild animals are rarely overcome the attention of the public opinion and institutions is increasing.
Scarce data are available on the presence of mycotoxins in wild animal meat or the food chain (Deutz et al., 2000).
The Chernobyl disaster in 1986 needs a specific focus. The accident implied a fallout of different elements, contaminating meat of wild ungulates in various countries; northern Europe, Austria and eastern Germany and probably eastern Italian Alps. Ungulate meat contamination by 137Cs (caesium) was followed by a decay although showing seasonal peaks (Fielitz et al., 2009). These peaks are mainly related to diet composition according to feeding habits; for roe deer contamination was higher in autumn (Fielitz et al., 2009), for wild boar was higher in summer declining in autumn and winter (Hohmann and Huckschlag, 2005). It is important to highlight that large part of roe deer and wild boar (Strebl and Tataruch, 2007) harvested in highly contaminated areas exceed the EU threshold for foodstuffs of 600 Bq radiocaesium per kg of fresh meat.
Since entering the eastern EU at the start of 2014, African swine fever (ASF) has spread locally (Poland, Latvia, Lithuania, Estonia) in the wild boar population, independently of outbreaks in domestic pigs. The risk of African swine fever (ASF) as a re-emerging disease was emphasized by the EU (COMMISSION IMPLEMENTING DECISION, 2014/178/EU). Since ASF is a highly contagious and fatal disease of domestic pigs and wild boar, transmitted through direct contact, ingestion, and certain tick species, restriction to movement and trade of animals including semen and products was adopted for some re-emerging or endemic presence areas.
