by Alejandro Gutierrez, Director of Breeding, The Center for Aquaculture Technologies, United States of America
In the rapidly evolving world of aquaculture, where the demand for seafood continues to rise, improved efficiency and sustainability are crucial. To meet this growing demand, the industry has turned to a time-tested strategy: selective breeding. In this article, we explore the importance of selective breeding in aquaculture, review various types of breeding programs, and offer insights to make informed decisions.
Why Selective Breeding Matters
Technically speaking, selective breeding is the process of improving one or more desirable traits of a cultured species through the selection of superior parents. A breeding program is how this idea is put into action, using specific tools and methods. It should be designed to maximize the economic return for a commercial aquaculture producer. Therefore, selective breeding isn’t just a buzzword; it’s a practical strategy that helps aquaculture achieve critical goals:
Improved Quality: One of the primary motivations behind selective breeding is to enhance the quality of farmed aquatic species. By selectively breeding for desirable traits like rapid growth, disease resistance, and survival, we can produce fish and other aquatic organisms that meet consumer preferences and market demands.
Enhanced Productivity: Productivity is the lifeblood of aquaculture. Selective breeding allows us to create strains of fish, crustaceans, or shellfish that grow faster and more efficiently, leading to increased yields and reduced production costs.
Sustainability: Sustainable aquaculture practices are essential for safeguarding our aquatic ecosystems. By selectively breeding for traits that minimize environmental impact, such as reduced waste production and efficient feed utilization, we can create a more sustainable future for the industry.
Exploring Options
There are numerous ways to organize a breeding program. Here are three common options to consider.
Mass Selection Assisted with Molecular Markers
Mass selection is a process where you pick the best individuals based on visible traits (phenotypes) and cross them to create the next generation. However, it comes with a caveat – this strategy works effectively for straightforward and direct traits like size, shape, or color.
There’s another crucial aspect to consider. In mass selection, you might end up selecting closely related individuals (leading to inbreeding). This can cause issues in the long run, as after several generations, genetic gains can diminish, potentially causing the program to collapse. To prevent this, molecular markers and genomic information are often employed to track diversity and levels of inbreeding within the population, ensuring that the breeding program remains robust and sustainable.
Family-Based Breeding
This approach involves selectively crossing the most promising families within a population to produce the next generation. It relies on the careful consideration of both observable traits (phenotypic) and ancestry records (pedigree). By combining individuals from families with superior characteristics for any type of trait, this method estimates the genetic effects of specific traits in various environments, ultimately enhancing the desired traits in the succeeding generations. Importantly, several traits can be selected for at the same time using this approach and a selection index.
Genomic Selection
Genomic selection is an advanced breeding strategy that identifies and mates the most promising individuals based on their Genomic Estimated Breeding Values (GEBV) to create the next generation. This highly effective method integrates phenotypic data, pedigree, and genomic information to significantly enhance precision and responsiveness in selecting for specific traits and adapting to various environmental conditions. This method generates the most rapid genetic gain per generation, maintains genetic diversity extremely well, and can address improvement in multiple traits.
Building the Foundation
To effectively implement selective breeding programs aquaculture companies must possess a range of critical capabilities. This begins with having the necessary technical expertise in genetics and breeding principles to make informed selections of breeding candidates. Efficient data collection and analysis tools are vital for evaluating traits and tracking pedigree information accurately. For genomic selection programs, access to cutting-edge genomic technologies is essential for precision.
It’s important to note that there’s no competition between the types of breeding programs you can implement. Instead, the choice depends on your specific situation. Each breeding program has its strengths and is suited to different contexts. Mass selection, family-based breeding, and genomic selection are all valuable tools in the aquaculture industry’s toolbox, and the right choice depends on the unique goals and resources of each company. The key is to make an informed decision that aligns with their aquaculture operation’s objectives and long-term vision.
“Many clients approach us with a strong inclination toward genomic selection, considering it the industry’s go-to solution. However, we believe in a tailored approach. By thoroughly evaluating their business structure, production methods, goals and available resources, we often recommend a different path that aligns better with their unique circumstances.’ – says Alejandro Gutierrez, Director of Genetic Services at the Center for Aquaculture Technologies (CAT).
From this perspective, having access to specialized expertise can be a game-changer. Producers often find it beneficial to collaborate with partners who have expertise in genetic analysis, breeding program development, and genomic technologies. Companies like CAT offer consultancy in breeding and genotyping services tailored to the unique needs of aquaculture operations and can provide valuable guidance and technical assistance. By leveraging these services, producers can enhance their capabilities, make informed breeding decisions, and optimize their breeding programs for improved outcomes. Selective breeding programs serve as the foundational step in shaping the genetic characteristics of aquaculture species. Once these programs have laid a solid genetic groundwork, genome editing techniques can then be employed to precisely fine-tune specific traits, offering even greater control over the genetic makeup of aquatic organisms. This combined approach provides a robust foundation for the sustainable growth of the aquaculture industry.
Published in the August 2024 issue of International Aquafeed.
