Pedigree analysis of Korean native chickens: unraveling inbreeding and genetic diversity

This study assessed the trends in inbreeding, effective population size, and genetic diversity across six Korean native chicken lines using pedigree records from 54,383 chickens. Understanding these genetic parameters is significantly important for maintaining healthy and viable chicken populations. The primary objective was to analyze the pedigree data to assess the levels of inbreeding and genetic diversity and to evaluate the effective population size across the different lines. Pedigree analysis revealed that pedigree completeness peaked in the first generation and declined in subsequent generations for all lines. Line A exhibited a mean inbreeding coefficient of 0.0201, whereas the other lines displayed lower mean values ranging from 0.0009 to 0.0098, indicating that inbreeding levels were within an acceptable range and considered safe from extinction. Average relatedness consistently increased with time. Individual increases in inbreeding were the highest in Line A (0.62%), with smaller increases in the other lines ranging from 0.02 to 0.23%. Effective population sizes varied from 81 to 2500, with average coancestry within parental populations ranging from 0.0032 to 0.0290. The f_e/f_a ratio between 1.00 and 1.69 in the 6 lines suggested a moderate impact during bottleneck events, with subsequent populations recovering well. The genetic diversity loss due to genetic drift and unequal founder contributions ranged from 0.66-3.15%, indicating that considerable genetic variability remains within the populations. The results of this study have practical applications in the management and conservation of genetic resources in poultry breeding programs. By highlighting the importance of monitoring inbreeding and maintaining genetic diversity, the findings can help develop strategies to ensure the long-term sustainability of these chicken lines. This study provides valuable insights into the genetic management of Korean native chicken lines, emphasizing the need for strategic breeding practices to preserve genetic health and diversity.