Pulina G., Dimauro C., Stella A., Ciani E., Moioli B.5, Pilla F., Crepaldi P. and Maciotta N.P.P.
Dipartimento di Agraria, University of Sassari, via E. De Nicola, 07100, Sassari, Italy
In livestock species, DNA-based assignment tests are generally used to trace and certify the origin of animal products. A certified traceability process is of great importance for products with Protected Designation of Origin (PDO) or Geographical Indication (PGI) labels. Moreover, it could be useful to valorize niche products obtained from breeds grazing in mountain areas. At present, several animals of different livestock species and breeds have been genotyped in many countries for genomic selection purposes. They could be therefore conveniently used to develop new assignments methods. In the present research, genotypes from the Illumina’s BovineSNP50 and OvineSNP50 BeadChips were used to develop an assignment method based on three multivariate statistical techniques: the stepwise discriminant analysis (SDA), the canonical discriminant analysis (CDA) and the discriminant analysis (DA). The SDA was used to select the most informative markers; the CDA tested if the discrimination of involved groups was significant; the DA assigned individuals to the true group of origin. Around 2,300 genotyped bulls belonging to 3 different breeds and 460 genotyped sheep belonging to 21 Italian sheep breeds were involved in the study. In both cases, 10% of randomly selected animals was used in the validation procedure. The SDA selected 48 and 108 top discriminant SNPs for bulls and sheep, respectively that were able to correctly assign animals to the true breed of origin. Those markers could be further used to develop two low cost customized essays to trace foodstuffs derived from the involved breed.