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Accueil du site → Doctorat → Ethiopie → Genetic parameters, productivity indices and breeding plans for designing community-based goat breeding programs in Ethiopia

Haramaya University. (2016)

Genetic parameters, productivity indices and breeding plans for designing community-based goat breeding programs in Ethiopia

Jembere, T.

Titre : Genetic parameters, productivity indices and breeding plans for designing community-based goat breeding programs in Ethiopia

Auteur : Jembere, T.

Université de soutenance : Haramaya University.

Grade : Doctor of Philosophy (PhD) 2016

Résumé partiel
The overall objectives of this dissertation were to improve access to improved/selected bucks by farmers of the research sites and to contribute to their food security and income improvements. The specific objectives were : 1) to present reliable genetic parameter estimates based on meta-analysis of literature reports ; 2) to evaluate production and productivity of three indigenous goat breeds in Ethiopia namely Abergelle (AB), Central Highland (CH) and Woyto-Guji (WG) and have bench mark production and productivity estimates for the ongoing Community Based Breeding Programs (CBBPs) in Ethiopia ; 3) to evaluate alternative breeding scenarios in the CBBP of the three goat breeds including dam-side selection, genomic selection and two-tier breeding programs ; and 4) to assess the need for recording birth weight in CBBP of small ruminants. This dissertation was based on four articles/manuscripts. Accordingly, in article 1, unweighted and weighted average genetic parameters including direct heritability (ha2), maternal heritability (hm2), ratio of common environmental variances (c2), repeatability (R), phenotypic (rp) and genetic (rg) correlations for growth, reproduction and milk production traits in goats were presented. Unweighted averages across publications were obtained directly. For the calculation of weighted average ha2, hm2, c2 and R, the inverse of their variances were used. Weighted average rp and rg were transformed to an approximate normal scale using Fisher’s Z transformation and then transformed back to correlations. Weighted average ha2 for growth, reproduction and milk production traits ranged from 0.03 to 0.45, 0.00 to 0.17 and 0.15 to 0.22, respectively. Weighted averages rp and rg correlations among growth traits ranged from -0.06 to 0.84 and 0.01 to 0.98, respectively. It seemed that weighted average ha2, hm2, c2, R, and rg are more reliable for two reasons : weighted estimates were more conservative than values based on relatively higher number of records and the absence of significant effects of the tested fixed factors on some parameter estimates

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