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

Abstract

BackgroundAt present the Croatian Turopolje pig population comprises about 157 breeding animals. In Austria, 324 Turopolje pigs originating from six Croatian founder animals are registered. Multiple bottlenecks have occurred in this population, one major one rather recently and several more older and moderate ones. In addition, it has been subdivided into three subpopulations, one in Austria and two in Croatia, with restricted gene flow. These specificities explain the delicate situation of this endangered Croatian lard-type pig breed.MethodsIn 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.ResultsThe 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.ConclusionsOne 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.

Substantial hybridisation between wild boars (Sus scrofa scrofa) and East Balkan pigs (Sus scrofa f. domestica) in natural environment as a result of semi-wild rearing in Bulgaria

“…The population genetic indices H o and H e are similar among all analyzed genetic groups and in accordance with those reported by Druml et al (2012) for local Balkan pig breeds in Austria (Mangalica, A r = 3.8, H o = 0.58, and H e = 0.54), Croatia (Black Slovonian, A r = 5.4, H o = 0.59, and H e = 0.64 and Turopoljski Lug, A r = 3.3, H o = 0.38, and H e = 0.37), Serbia (Mangalica, A r = 3.9, H o = 0.58, and H e = 0.54), and Bosnia-Herzegovina (Bosnian mountain pig, A r = 4.2, H o = 0.62, and H e = 0.58). The observed mean allelic richness in EBP (A r = 7.70) is substantially higher than in breeds studied by Druml et al (2012) which may be explained by historical genetic introgression with wild boars.…”

“…The observed mean allelic richness in EBP (A r = 7.70) is substantially higher than in breeds studied by Druml et al (2012) which may be explained by historical genetic introgression with wild boars.…”

A multi-farm assessment of Greek black pig genetic diversity using microsatellite molecular markers

“…Negative values of inbreeding coefficient were also observed in the Serbian Mangalica breed and in a Turopolje herd, suggesting an excess of heterozygotes due to non-random mating (Druml et al, 2012). As far as we know, the heterozygote excess in our study is among the highest ever reported.…”

“…In our study, microsatellite markers showed a considerably high degree of genetic polymorphism within and between populations on the basis of their allele numbers per locus (N A ) and their genetic heterozygosity (H E ). The mean number of alleles per locus (N A = 12.27) was the highest among several European and Asian breeds including 11 European pigs breeds (N A = 10.6) (Laval et al, 2000), the Taihu pig breed (N A = 8) (Fan et al, 2002), the Iberian pig breed (N A = 7.2) (Fabuel et al, 2004), the Cinta Senese pig breed (N A = 9) (Scali et al, 2012), the Nero Siciliano pig breed (N A = 9.96) (Guastella et al, 2010), six Chinese indigenous pig breeds (N A = 10.35) (Wang et al, 2011), and the Croatian Turopolje pig breed (N A = 7.7) (Druml et al, 2012). However, the mean number of alleles per locus was significantly higher in several Chinese indigenous pig populations (NA = 24.8) (Li et al, 2004).…”

The effects of recent changes in breeding preferences on maintaining traditional Dutch chicken genomic diversity

“…Assessing the genetic diversity and understanding the relationships among and within populations are the first necessary steps to establish conservation priorities and strategies (Berthouly et al 2010;Druml et al 2012). Large sample sizes are usually recommended to accurately estimate population statistics.…”