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dc.contributor.advisorBerg, Peer
dc.contributor.authorWinnberg, Kirsti
dc.date.accessioned2021-01-25T11:43:45Z
dc.date.available2021-01-25T11:43:45Z
dc.date.issued2020
dc.identifier.urihttps://hdl.handle.net/11250/2724522
dc.description.abstractBackground: Despite commercial breeding being part of the genomic era, routine use of genotype data to govern inbreeding is still scarce. Recent studies have found acceleration of inbreeding rates after implementation of GS. Development of robust and reliable genomic inbreeding metrics should therefore be a priority. Aim of this study was to optimize detection of runs of homozygosity (ROH) and use these along with inbreeding coefficients based on pedigree and genomic relationship matrix to examine trends in genome wide and region-specific inbreeding after implementation of GS in Norwegian Red Cattle (NR). Methods: Pedigree data from whole population and genotype data from 80.999 animals (on 777K chip) was used to estimate inbreeding coefficients and rates of inbreeding. FPED, FGRM and FROHwas used to assess inbreeding trends in NR before and after implementation of GS. ROH was also used to examine inbreeding on individual chromosomes. Detection of ROH in PLINK was optimized using genome coverage validation method. Results: Parameter settings and density of data set was found to strongly influence ROH detection. No significant increase in rates of inbreeding was found after implementation of GS in NR, neither in genome wide nor chromosomal estimates. We detected an abundance of short ROH in the genome of NR, indicating little recent inbreeding. Rates of inbreeding were well within recommended 0.5-1% limits. High correlations between FROH and FGRM indicate that these metrics can be used for routine inbreeding estimation in NR. Conclusion: We lay the foundation for a framework that can be used to develop methodology for genomic inbreeding evaluation in NR. Calculations in this thesis only had 3,5 years of GS to base upon, and paucity of data strongly limits estimates. Estimates should be repeated when more time from implementation of GS has elapsed. Development of methods using genomic information to manage inbreeding in NR is advisable.en_US
dc.language.isoengen_US
dc.publisherNorwegian University of Life Sciences, Åsen_US
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 Internasjonal*
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/deed.no*
dc.titleTrends in runs of homozygosity and inbreeding in Norwegian Red Cattle before and after implementation of genomic selectionen_US
dc.title.alternativeUtvikling i genomisk innavl etter implementering av genomisk seleksjon hos Norsk Rødt Feen_US
dc.typeMaster thesisen_US
dc.subject.nsiVDP::Agriculture and fishery disciplines: 900en_US
dc.description.localcodeM-HVen_US


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Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal
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