Pedigree-Based Description of Danubia Alba Rabbit Breed Lines

TL;DR

This study analyzes the genetic diversity and breeding history of Danubia Alba rabbit lines to support sustainable breeding practices.

Contribution

The study provides a detailed pedigree-based analysis of genetic variability and inbreeding in Danubia Alba rabbit lines.

Findings

Genetic variability in Danubia Alba rabbit lines has decreased, likely due to selection practices.

Inbreeding levels are primarily influenced by previously fixed alleles rather than recent genetic loss.

Effective population sizes suggest no critical risk for maintaining genetic diversity in these rabbit lines.

Abstract

Maintenance of genetic diversity is important for commercial livestock breeds as well. The Danubia Alba rabbit is a synthetic breed; its breeding goal is meat production. The primary goal of our study was to provide information about the demographic history of Danubia Alba and support the breeder company during its selection work. Besides homozygosity, the deepness of the pedigree, the generation interval, and gene variability were evaluated. We found that the lines of genetic variability decreased, probably due to the selection work. The homozygosity of the lines was estimated using different methods, like Ballou’s, Wright’s, and Kalinowski’s inbreeding coefficients. Though current inbreeding coefficients were different among lines, the present inbreeding level came mostly from previously fixed alleles for each of them. Effective population sizes were estimated, and none of the lines was found to be critical.

The diversity of livestock animal breeds is an integral part of global biodiversity and requires careful management for sustainability and future availability. Avoiding inbreeding is a crucial aspect of mating of breeding animals. Our aims were to describe the quality of the pedigree, generation interval, gene origin, inbreeding, and effective population size of Danubia Alba rabbit lines. Line “D” is the maternal, whereas lines “C” and “X” are used as the paternal lines. The pedigree information was followed back from the actual breeding rabbits up to the founder animals. The rabbits having offspring in 2023 were chosen as reference populations for each line. The complete generation equivalent (GenCom) was 17.68 for line “C”, 18.32 for line “D”, and 17.49 for line “X”, respectively. The maximum number of generations (GenMax) was above 30 for each line. The estimated bottleneck effect is mostly the result of selection and not a real genetic loss. The Wright inbreeding coefficient (F_Wright) was the highest for the “X” line rabbits, whereas it was the lowest for the line “D”. Kalinowski’s decomposition of inbreeding showed that it originated mostly from the past; the current fixation of alleles was quite similar for the line “C” and “D”. Based on the predicted effective population sizes, it seems that there is no problem in maintaining of Danubia Alba lines.

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