Pedigree analysis of the Lipizzan horse populations from Bosnia and Herzegovina and Serbia: Structure, inbreeding and genetic variability

Abstract

The aim of this study was to evaluate population parameters and to describe the genetic variability in the Lipizzan horse populations from stud farms in Bosnia and Herzegovina (BH) and Serbia (SRB), reported for the first time in the literature. Pedigree data were collected from the national studbooks. Pedigree data for 2 521 horses were used in the analysis, for a reference population covering live animals in the current population. The average generation interval was 10.78 ± 0.36 (BH) and 12.12 ± 0.59 (SRB) years. The equivalent complete generations ranged from 5.49 (BH) to 14.86 (SRB). The average inbreeding values were 3.96 (BH) and 2.12 (SRB), whereas the average relatedness values were 9.24 (BH) and 4.13 (SRB). Values for f<sub>e</sub>, f<sub>a</sub>, f<sub>g</sub><sub> </sub>and the f<sub>e</sub>/f<sub>a</sub><sub> </sub>ratio were 21, 12, 6.031 and 1.75 in BH Lipizzan horses, and 79, 20, 9.766 and 3.95 in SRB Lipizzan horses. The number of ancestors explaining 50% of genetic diversity in the BH and SRB reference populations was five and eight, respectively. The effective population sizes obtained from regression on the birth dates were 43.67 (BH) and 211.78 (SRB). The investigated genetic variability parameters were higher in the SRB Lipizzan population than in the BH population. The results of pedigree and genetic structure research indicate the need for a comprehensive approach to monitoring to improve future breeding and genetic diversity in the BH and SRB Lipizzan populations.