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Báo cáo khoa hoc:" Prediction of the response to a selection for canalisation of a continuous trait in animal breeding"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Prediction of the response to a selection for canalisation of a continuous trait in animal breeding | 423 Genet. Sei. Evol. 30 1998 423-451 Inra Elsevier Paris Original article Prediction of the response to a selection for canalisation of a continuous trait in animal breeding Magali SanCristobal-Gaudy a Jean-Michel Eisen b Loys Bodin b Claude Chevaleta a Laboratoire de génétique cellulaire Institut national de la recherche agronomique BP27 31326 Castanet-Tolosan cedex France b Station d amelioration génétique des animaux Institut national de la recherche agronomique BP27 31326 Castanet-Tolosan cedex France Received 7 November 1997 accepted 31 August 1998 Abstract - Canalising selection is handled by a heteroscedastic model involving a genotypic value for the mean and a genotypic value for the log variance associated with a single phenotypic value. A selection objective is proposed as the expected squared deviation of the phenotype from the optimum of a progeny of any candidate for selection. Indices and approximate expressions of parent-offspring regression are derived. Simulations are performed to check the accuracy of the analytical approximation. Examples of fat to protein ratio in goat milk yield and muscle pH data in pig breeding are provided in order to investigate the ability of these populations to be canalised towards an economic optimum. Inra Elsevier Paris canalising selection heteroscedasticity selection index Resume Prediction de la réponse à une selection canalisante d un caractère continu en génétique animale. Le problème de la selection canalisante est traité grace à un modèle hétéroscédastique mettant en jeu une valeur génétique pour la moyenne et une valeur génétique pour le logarithme de la variance toutes deux associées à une seule valeur phénotypique. Pour un objectif de selection visant à minimiser 1 espérance des carrés des differences entre le phenotype et 1 optimum pour un descendant d un candidat à la selection des index sont estimés et des expressions approchées de la regression parent-descendant sont calculées. La precision de ces .