Mainstream Aquaculture Group has operated a Barramundi Breeding Program for 17 years and introduced genomic selection as the core method of commercial trait improvement in 2018. A mix of genomic and marker assisted selection on individuals is coupled with pedigree-based methods to improve commercial traits and create optimal and sustainable breeding lines. This has enabled identification of breeding lines that are tailored/optimised to specific farming environments (particularly open pond and RAS environments). It also drives development of a unique golden-coloured barramundi breeding line.
Commercial (farming) growth rates analysed over the three-year period 2019-2022 demonstrate a 15.8% (pond farming) and 15.2% (RAS farming) increase in growth rate. Improvements both predicted and measured since the implementation of genomic selection are discussed together with practical challenges related to interpreting performance results on farms. Specifically, uncoupling the underlying impact of genetics versus operational factors that drive commercial outcomes. Data is also presented on an early growth stage experiment where wild-type and commercial barramundi are compared under similar growing conditions in RAS. This experiment highlights improved growth and lower variance achieved through domesticated and improved stocks. Challenges faced in incorporating new genetics into advanced breeding programs are discussed.
Looking to the near future, improved robustness and specific disease resistance are in focus. A program to improve the capability of barramundi stocks to cope with common parasitic (cryptocaryon, amyloodinium) and bacterial (S. iniae) challenges in Australian farming environments is outlined. Also outlines is work using the genomic platform to improve disease resistance to exotic regional diseases and build a breeding nucleus capable of rapid response to in-bound biosecurity threats to the Australian Barramundi Industry.