Pedigree analysis of the former Valachian sheep

Abstract

The objective of this study was to assess the genetic variability of the former Valachian sheep breed. The analysis was based on the pedigree information of a single nucleus flock located in Northern Slovakia. The reference population was limited and consisted of 27 individuals (live animals born during the period 2007-2010). The results, therefore, need to be interpreted with caution. The whole pedigree population consisted of 137 individuals. The pedigree completeness, generation intervals, levels of inbreeding and of average relatedness were computed for both populations. The mean inbreeding for the whole population was 1.69% and the mean inbreeding for the reference population was 6.48%, respectively. The mean average relatedness for the whole population was 5.36% and the mean average relatedness for the reference population was 10.55%, respectively. An individual increase in inbreeding, the realized effective population size and the analyses of founders and ancestors were computed for the reference population. The mean individual increase in inbreeding was 2.43% and the realized effective population size was 20.6 animals. The number of founders was 62 animals, the effective number of founders as well as the number of ancestors was 20 animals, the effective number of ancestors contributing to the reference population was 5 animals and the number of ancestors explaining 50% of genetic diversity for the reference population was 2 animals. Although the findings may depend on the chosen reference population and may reflect the completeness of the pedigree, they enable to assess the available genetic variability and may be considered a basis for additional research as well as a proposal for measures aimed at maintaining the breed diversity.