Genetic Traceability of livestock products
Kulcsszavak:genetic traceability, DNA identification, livestock products, food safety
Aim of this review was to describe the novel approaches on genetic traceability of livestock products. The term traceability, regarding the livestock production sector, means the ability to keep under unfailing control the products origin and animals identity along all passages of the food chain, from farm to fork. In this way it represents a warranty both for the consumers and the producer and it will permit to know where, who and how a product has been produced. It is clear that traceability could be an important tool in order to preserve and to turn to account the livestock products, especially for typical ones. Different kinds of traceability (conventional, aromatic, geographic and genetic) are discussed in order to explain the principles on which they are based and their possible applications. Genetic traceability is based on DNA identification technology through the use of molecular markers. The genetic traceability might be used at four different levels: individual, cohort/group, breed and species. Regarding genetic traceability, the effective discrimination at level of unique animal identification depends on reducing the probability to find two individual sharing, by chance, the same genetic profile to an acceptable low threshold. For example in a standard proceeding even a two locus test with polymorphic markers as microsatellites (one in sixty-four chance of error, i.e. accidental match) might be sufficient to reach a verdict, but for a forensic case, eight loci (one in 16.8 million chance of error) might be sufficient to reach a verdict. The effective discrimination from the point of animals group (herd, breed or species) identification is based on two different approaches: deterministic and probabilistic. Deterministic approach is based on the analyses of neutral molecular markers specific for each breed and/or genes with different allelic forms fixed within breed as genes affecting coat colour. Probabilistic approaches are based on two methods, the first using the allelic frequencies typical of each group (herd, breed or species) while the second using genetic distances among groups. In conclusion, this review, showed as the novel approaches on genetic traceability of livestock products is an available method even if it should be improved in terms of cost reduction for single sample, work effort, reproducibility and accuracy of results. At the time genetic traceability is an important method for origin identification of livestock products and a tool for guarantee conventional traceability system as routine method for food safety.