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Designing, technical evaluation and profitability estimation of breeding strategies based on molecular information for small ruminant species

Shumbusho, Félicien. Designing, technical evaluation and profitability estimation of breeding strategies based on molecular information for small ruminant species. PhD, Institut National Polytechnique de Toulouse, 2014

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Official URL: http://ethesis.inp-toulouse.fr/archive/00002587/

Abstract

Implementing genomic selection (GS) in small ruminant breeding programs is still at the research and development level. This new way of selection in animals and plants was made possible thanks to the development of low costs, high density SNP chips. It proved to be highly beneficial in dairy cattle breeding programs. The French small ruminant industries are strongly interested in evaluating the efficiency of this tool in their situation. However, they are also very cautious given the inherent differences in terms of capacity and functionalities between dairy cattle and small ruminant breeding programs. This study is part of bigger efforts mobilized to evaluate the use and management of genomic information in sheep and goats breeding programs. The PhD work examined (1) the impact of genomic selection on genetic gain of small ruminant breeding programs; (2) the economic efficiency of genomic selection in small ruminant, through an example of a meat sheep breeding program; (3) the benefits of optimizing the use of decision variables on genetic gain; and (4) contributed some ideas on how to optimize the choice of individuals in the reference population. The modeling parts were done by deterministic methods and the examples focused on the existing breeding programs (dairy sheep, meat sheep and dairy goats) with medium to small size breeding units. The results of this study suggest that adopting genomic selection can be more profitable than classic selection in terms of genetic gain, provided that, at least, a medium size reference population is available (around 2,000 individuals). They show, especially in dairy breeds, that the GS potentials of reducing generation interval could greatly increase the genetic gain. In meat sheep breeding program, exploring the possibility of combining genomic information and meat phenotypes gave higher genetic gain than classic or pure genomic selection. In terms of economic impacts, results of the meat sheep breeding program we modeled show that all genomic selection strategies are more expensive than classic selection. However, the contribution margins (total revenues minus total variable costs) of some GS variants were slightly higher than benefits from classic selection. The study also shows, across breeds and selection strategies, that optimizing the use of decision variables could greatly increase the genetic gain and benefits, compared to the current situation. With this thesis we can conclude that adopting genomic selection in small ruminant breeding programs is possible and could be more beneficial than classic selection in some cases. However, there are more obstacles compared to dairy cattle, especially, construction of reliable reference populations and high costs of genotypes relative to the value of selection candidates. These might delay implementation in general or prevent it in some breeds.

Item Type:PhD Thesis
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Institution:Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
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Research Director:
Elsen, Jean-Michel
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Deposited On:31 Oct 2014 22:59

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