ABSTRACT: The optimal contribution selection method and the simulated annealing algorithm were used to maximize
the genetic gain and reduce inbreeding in fish breeding populations. This study considered the following mating designs:
full factorial (3 x 3); full factorial (6 x 6) and nested (6 males x 18 females). A quantitative trait based on a strictly additive
and polygenic model was simulated. Two levels for the number of genotyped offspring (360 or 720) and three levels
of heritability (0.1; 0.3; 0.5) were assumed. The best results in terms of DF and DG were obtained with the full factorial
design (6 x 6) and considering a trait with a high heritability. The optimal family size was found at 20 fish per mating.
