Genomic insights on the Parma and Piacenza Italian native turkey breed for conservation and traceability

The Parma and Piacenza turkey is among the few surviving Italian native turkey breeds, representing an important genetic resource currently at risk with roughly 100 animals alive. We performed a genome-wide characterization of this population using the Axiom® Turkey Genotyping Array (634 K SNPs) and compared it with a Commercial line. After quality control, 134 individuals and 398,401 SNPs were retained for analysis. Principal component and Discriminant analyses revealed strong differentiation between the local and Commercial populations, while also detecting farm-level substructure within the Parma and Piacenza breed. Runs of homozygosity (ROH) indicated markedly higher genomic inbreeding in the local breed (mean FROH = 0.34) compared to the Commercial one (mean FROH = 0.14), reflecting both long-term drift and recent inbreeding. Genomic differentiation analysis (FST) identified multiple highly divergent regions, and penalized regression (LASSO) selected a sparse panel of 22 SNPs capable of fully discriminating between local and Commercial turkeys, providing a potential tool for breed authentication and traceability. Overlapping results from ROH, FST, and LASSO highlighted candidate genomic regions under selection in the local population, including interesting loci overlapping TRIM42 and CLSTN2 genes, which have a known function towards immunity and reproduction, respectively. These findings reveal unique genomic features of the Parma and Piacenza turkey, provide tools for conservation and traceability, and emphasize the urgent need to preserve this highly endangered heritage population.