Inbreeding, microsatellite heterozygosity, and morphological traits in Lipizzan horses.

The research explores the impact of inbreeding and reduced heterozygosity on the morphological traits of Lipizzan horses, a closed and small population. The study analyzed the correlations between these genetic factors and 27 physical attributes in 360 Lipizzan mares, however, found no considerable effects on the studied traits.

Research Methodology and Factors Analyzed

• The study revolves around Lipizzan horses, a closed population that can offer detailed insights into the effect of inbreeding and gene diversity on physical traits.
• A total of 27 morphological traits were measured in 360 Lipizzan mares.
• These values were then compared with the individual inbreeding coefficients of the horses, and individual heterozygosity and mean squared distances (mean d(2)) between their microsatellite alleles.
• The genetic data for heterozygosity and mean d(2) were obtained from 17 microsatellite loci distributed over 14 chromosomes.

Results and Observations

• The multivariate analysis indicated that the stud (the place where horses are kept and bred), the age at which the measurements were taken, and mean d(2) have substantial effects.
• In univariate analyses, significant correlations were found between the length of pastern-hindlimbs and inbreeding coefficient, the length of cannons-hindlimb and mean d(2), and length of the neck and mean d(2).
• However, when P values were adjusted for multiple tests using Hochberg’s step-up Bonferroni method, only the correlation between the length of the neck and mean d(2) remained significant.

Conclusion

• The conclusion of this study is that no substantial overall effects of inbreeding, microsatellite heterozygosity, and mean d(2) were found on the morphological traits studied in the Lipizzan horse population.