Strategies for Improvement of Indigenous Ethiopian Cattle Breeds: Breeding Plans and Sequence Polymorphisms of Selected Candidate Genes (BoLA-DRB3 and Leptin) as a Potential Molecular Markers
| dc.contributor.advisor | Sisay, Tesfaye (Professor) | |
| dc.contributor.advisor | Dadi, Hailu (PhD) | |
| dc.contributor.author | Mandefro, Ayele | |
| dc.date.accessioned | 2021-11-22T07:01:23Z | |
| dc.date.accessioned | 2023-11-18T09:50:19Z | |
| dc.date.available | 2021-11-22T07:01:23Z | |
| dc.date.available | 2023-11-18T09:50:19Z | |
| dc.date.issued | 2021-05-01 | |
| dc.description.abstract | Agriculture is the major pillar of Ethiopia’s economy. The livestock sector is one part of agriculture, accounting for about 45% of the total value of agricultural production. Simulation method and genomic selection approaches were implemented to select superior animals for the aim of enhancing production and productivity. Two indigenous cattle breeds of Ethiopia (Boran and Horro) were simulated with the objective of evolving applicable breeding programs. Boran was evaluated for beef, milk, and both beef and meat (dual purpose) while Horro was evaluated for milk and dual purposes. Yearling weight, milk yield, age at first calving, calving interval, and calf survival to yearling were defined as selection criteria for milk production. Moreover, yearling weight, age at first calving, calving interval, and calf survival to yearling were used to improve beef production in the Boran breed. For all goal traits examined, more genetic gains were found from bull selection groups than cow selection groups. The genetic polymorphisms of the BoLA-DRB3 and leptin gene in Ethiopian and Asian zebu and taurine cattle breeds were evaluated by sequence-based typing (SBT). For the BoLA-DRB3 exon2 locus we detected 59 total alleles and 16 alleles were newly identified from this study. The Hardy Weinberg genetic equilibrium (HWE) of all the breeds investigated revealed non-significant excess of heterozygosis that could show over-dominant selection. The results of pairwise FST values directed low genetic differentiation of the Ethiopian breeds with Asian Zebu and taurine, rooted from the evolutionary history of cattle breeds. Exon2 and exon3 were evaluated for leptin gene IV | P a g e polymorphism. Five SNPs at positions 73 (C>T), 143 (C>A), 399 (T>C), 411 (T>C), and 495 (C>T) were identified and only the second SNP (C143A) was new to this study. Mutations detected on exon2 region were missense that causes a change of amino acids from arginine to cysteine (R25C) and from threonine to lysine (T48K). The evolutionary divergence showed that large-sized cattle breeds were closely clustered together. Simulation study could be used to improve the performance of cattle production. Also, selection of superior animals based on selected candidate genes (BoLA-DRB3 and leptin) could be important to improve cattle genetics. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/28812 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | PCR-SBT | en_US |
| dc.subject | SNP | en_US |
| dc.subject | Leptin | en_US |
| dc.subject | BoLA-DRB3 | en_US |
| dc.subject | Cattle | en_US |
| dc.title | Strategies for Improvement of Indigenous Ethiopian Cattle Breeds: Breeding Plans and Sequence Polymorphisms of Selected Candidate Genes (BoLA-DRB3 and Leptin) as a Potential Molecular Markers | en_US |
| dc.type | Thesis | en_US |