Genetic Diversity of Ethiopian Indigenous Chickens a Base for Sustainable Genetic Improvement: A Review

The estimated chicken population of Ethiopia is about 57 million, of which 78.8% are indigenous characterized by low egg production, late maturing and long brooding behavior but celebrated for their hardiness, exceptional scavenging abilities and robust natural immunity against common diseases. The objective of this paper was to review the genetic diversity and improvement interventions of indigenous chicken populations. The review process was started by collecting research articles that were done on genetic diversity and chicken genetic improvement strategies by searching tools such as Google Scholar, PubMed and Web of Science with search terms genetic diversity, genetic characterization and chicken genetic improvement. Lastly, we organized ideas and the write-up was done. Indigenous chicken shows high genetic diversity within the population. The indigenous chickens have high number of alleles (6.25), an effective number of alleles (4.85), observed (55%) and expected (57%) heterozygosity and 90% within-population variation which is considerable variation as unselected African native chickens. Higher heterozygosity levels and considerable genetic variation warranted a further use of ecotypes in improvement through selective breeding. Genetic marker studies showed positive selection signatures of improved from unimproved local chickens. Selective breeding done on Horro chicken breed in Ethiopia saw a remarkable 107.7% and 176.4% improvement in body weight egg number. Uncontrolled dissemination and indiscriminate crossbreeding resulted in the erosion of adaptive local genetic resources. Therefore, improving and conserving indigenous chicken with selective breeding combined with molecular techniques and further studies on the genetic control of productivity traits are very crucial.