Mitochondrial Diversity of the East Balkan Swine (Sus scrofa f. domestica) in South-Eastern Bulgaria

The East Balkan Swine (EBS) is the only preserved local swine breed in Bulgaria and one of the few indigenous pig breeds in Europe. The EBS is distributed in the region of Eastern Balkan Mountains and the Strandja Mountain. To reveal the breed’s genetic profile, we analyzed 50 purebred individuals according to mitochondrial DNA (D-loop region, HVR1) and sequence analysis in the Scientific Center of Agriculture (Sredets region) in the country.

The obtained results show the presence of four haplotypes: three Asian specific haplotypes (H1, H2, and H3) and the European specific E1a1. The haplotypes H2 (6 %) and H3 (2 %) were newly described and were branched from the basic clade H1 (90 %). All haplotypes belong to the Asiatic clade A (98 %), except one sample assigned to the European haplogroup E1 (2 %) in contrast to samples from East North Bulgaria where Asiatic and Europen clades were with almost equal distribution. The coexistence of two mtDNA clades in EBS in Bulgaria may be related to the source of the pig populations and/or the historical crossbreeding with imported pigs.

In conclusion, due to its native origin, the East Balkan Swine may be the only possible option for a solution to the exhaustion of the beneficial genetic variation of available cultural breeds. With its participation, high-productive populations can be restored and established after a long and purposeful selection.