Prediction of the response to a selection for canalisation of a continuoustrait in animal breeding

Canalising selection is handled by a heteroscedastic model involving a geno typic value for the mean and a genotypic value for the log variance, associ ated with a single phenotypic value. A selection objective is proposed as t he expected squared deviation of the phenotype from the optimum, of a proge ny of any candidate for selection. Indices and approximate expressions of p arent-offspring regression are derived. Simulations are performed to check the accuracy of the analytical approximation. Examples of fat to protein ra tio in goat milk yield and muscle pH data in pig breeding are provided in o rder to investigate the ability of these populations to be canalised toward s an economic optimum. (C) Inra/Elsevier, Paris.