Correlation Analysis among the Various Inbreeding Coefficients of Pannon Ka Rabbits

In a closed population with a limited population size, mating of related animals is unavoidable. In this study, the genealogy data of a synthetic maternal rabbit breed called Pannon Ka were used to calculate different inbreeding coefficients. The evaluated animals were born between 1995 and 2020, and the pedigree consisted of 5819 animals that originated from 4205 rabbit does and from 1314 rabbit bucks. The pedigree was further extended with 16,013 dummy progeny records in order to calculate litter inbreeding coefficients. Besides the conventional Wright inbreeding coefficients, the so-called ancestral and new inbreeding coefficients were also calculated using the gene dropping method. By the end of the evaluated period, the litter inbreeding increased to almost 11 and 60% for Wright and Ballou inbreeding, while the Kalinowski and the Kalinowski new inbreeding coefficients were 9.25 and 16.67%, respectively. Correlation coefficients were calculated for the does and for the litters. Finally, the effects of pedigree length and completeness were also taken into account using the complete generation equivalents in a partial correlation analysis. Based on the results, it could be seen that the different ancestral inbreeding coefficients had high correlation. Similarly, the conventional Wright inbreeding coefficients showed strong correlation with the new inbreeding coefficients. On the contrary, the correlation between ancestral and new inbreeding coefficients was low. Taking the complete generation equivalent into account did not give unambiguous results. It could be concluded that the different inbreeding coefficients are based on different concepts, and they are clearly different population parameters.