Pedigree analysis of the Latvian Warmblood horse heavy type population

Abstract

A breeding program has been developed for the Latvian warmblood heavy type horses in Latvia, with the aim to preserve this type, because the number of these horses is small and the status of the local endangered breed has been granted. The aim of the study was to analyse the genetic structure, inbreeding and effective population size of the Latvian warmblood heavy type (LSB) horse population. Horses that were living at the time of the study on January 1, 2023 were used for the study. A total of 374 genetic resources live horses were analysed. Population structure analysis, inbreeding and effective population size were investigated. Calculations were done by POPREP (v1.0) software. The effective population size (Ne) decreased, however, since 2018 the decline in the size of the effective population has not been so rapid. In 2000, the Ne was 316 animals, and in 2020, it was 101 animals. Over the years, changes in the average inbreeding level in the LSB population were observed from year to year. In 2000, inbreeding was 1.39%, and in 2020 it was 1.47% with the average inbreeding level of 1.12%. Over the last 20 years, large changes in Ne have been observed, thus, the loss of genetic diversity in the LSB breed should be controlled.

Keywords

• effective population
• generation interval
• inbreeding
• horse breeding