Genetic diversity, population structure and subdivision of local Balkan pig breeds in Austria, Croatia, Serbia and Bosnia-Herzegovina and its practical value in conservation programs

In order to identify candidate breeding animals or gene pools for future conservation breeding programs, we studied the genetic diversity and population structure of this breed using microsatellite data from 197 individuals belonging to five different breeds.The genetic diversity of the Turopolje pig is dramatically low with observed heterozygosities values ranging from 0.38 to 0.57. Split into three populations since 1994, two genetic clusters could be identified: one highly conserved Croatian gene pool in Turopoljski Lug and the"Posavina" gene pool mainly present in the Austrian population. The second Croatian subpopulation in Lonjsko Polje in the Posavina region shows a constant gene flow from the Turopoljski Lug animals.One practical conclusion is that it is necessary to develop a "Posavina" boar line to preserve the "Posavina" gene pool and constitute a corresponding population in Croatia. Animals of the highly inbred herd in Turopoljski Lug should not be crossed with animals of other populations since they represent a specific phenotype-genotype combination. However to increase the genetic diversity of this herd, a program to optimize its sex ratio should be carried out, as was done in the Austrian population where the level of heterozygosity has remained moderate despite its heavy bottleneck in 1994.Many studies on the diversity of various pig breeds have been reported in the literature in recent years. As early as the 1990's, several research groups have worked on harmonizing data from these various genetic studies in multiple pig populations from Europe and China (PiGMaP [1], PigBioDiv1 and 2 [2-4]). For instance, the PigBioDiv projects include, among other data, around 50 European and 50 Chinese pig populations and a set of 50 microsatellite markers to study the pig genetic diversity in the main breeding and production areas. The major objective of these projects was to demonstrate how relevant analyses in overlapping countries can be carried out to study