Selective breeding is the process of improving one or more desirable traits of a cultured species through the selection of superior parents for the next generation. In shrimp, breeding programs are currently in use ranging from relatively simple mass selection plans to sophisticated application of genomic selection.
Phenotypes that can be selected directly such as growth are relatively easy to measure and select for in most breeding programs . Indirect or complex traits such as disease resistance, robustness, or selecting for a combination of important traits is more complicated both to measure and to fit into a statistical broodstock selection model. W e will briefly discuss the general concepts and common strategies for breeding program management, from the simplest requiring the least amount of investment to the more complex, requiring greater investment but delivering greater genetic gains across more traits. We will present information on mass selection, family selection, and genomic selection as applied to shrimp breeding. More importantly, we will illustrate the use of the phenotypes and genotypes for a breeding program and how the breeding strategy should be designed to maximize economic returns by balancing input costs with the expected genetic and economic gains for a commercial aquaculture producer. We use internal rate of return (IRR) as an economic metric to quantify choices in breeding strategy.
There are multiple options for enhanced selective breeding program management, each requiring different inputs and investment with varying potential returns and gains. Key to the design of a genetic improvement program is the consideration of each program’s breeding goals, size, and available budget along with selection and availability of appropriate tools to support such a design.