Increased profits in aquaculture through optimised dissemination schemes

We studied a typical breeding nucleus with dissemination of genetic material directly from the nucleus to the grow-out level by stochastic simulation. Profits could be increased through production and dissemination of specialised stocks suited for specific production environments or markets. Truncation selection of 50 sires and 200 dams (trunc ♂2.5% ♀10%) and of 5 sires and 25 dams (trunc ♂0.25% ♀1.25%) were compared to random selection of 50 sires and 200 dams (rand ♂2.5% ♀10%). Higher profit was obtained for all truncation selection schemes as compared to random selection, and increasing with decreasing proportion selected. By optimising the selection of parents, which are used for dissemination from the nucleus to the grow-out, instead of using randomly selected nucleus parents, an additional response corresponding of approximately 1.5 generations of selection in the nucleus was achieved. The effect of the correlation between the nucleus breeding goal and the breeding objective of the grow-out was that profit was highest when the correlation was high. With a negative genetic correlation between the traits, profit was still high if the trait with the highest heritability (i.e. the trait measured on candidate itself) had the highest economic value. The range of ΔF in the 7th generation in the nucleus was [− 0.0075–0.0269] with SD equal to 0.0056. The average over all the replicates was 0.0095. This study showed that selection of specialised stocks for specific breeding objectives from the nucleus to the grow-out level will give the grow-out producers a direct and extra genetic improvement and that selecting breeders in the nucleus for dissemination gives also more flexibility for a final product, by adapting economic weights for each grow-out producer.