The economic optimization of breeding programs in aquaculture

To meet the global demand for fish in a more sustainable manner, aquaculture needs to increase its economic and resource use efficiency. This can be achieved by genetic improvement of aquaculture species in breeding programs. The aim of this thesis is to study the economic optimization of breeding programs in aquaculture. First, the impact of selective breeding on European aquaculture was evaluated. Based on survey results, over 80% of the production was estimated to originate from breeding programs. Resulting economic benefits are predicted to increase cumulatively by about 100 million euro each year. For the economic optimization of breeding programs the first step is to optimize the relative emphasis on breeding goal traits, for which economic values need to be derived. This thesis presents a bio-economic model for the derivation of economic values of the production traits: growth rate, feed intake rate, mortality rate, and uniformity. The model was used to derive economic values for gilthead seabream aquaculture. The rate at which diseases spread across the farmed population is determined by Ro . Methods for the derivation of the economic value of Ro for macro- and microparasitic diseases were developed. The method for macroparasitic diseases was used to derive the economic value of Ro for sea lice in Atlantic salmon aquaculture in Norway. Once economic values have been derived, a breeding program’s design can be optimized. For an integrated breeding company cost-benefit analysis was used to evaluate alternative breeding program designs, with and without multiplier tier. Designs that shortened the genetic lag were shown to be more profitable. For each design the number of selection candidates was optimized with the objective to maximize the net present value, a measure of profitability. The optimum number of selection candidates was shown to increase with the length of the time horizon and production output of the company. For a specialized breeding company the allocation of budget over the numbers of phenotyped and genotyped full-sibs of selection candidates in performance tests was optimized with the objective to maximize gain in the aggregate genotype. The optimum was rather flat, but potential gains from optimization come at no extra cost. This thesis demonstrates that the optimization of breeding programs can improve the economic efficiency of aquaculture.