Amoebic gill disease (AGD) has been a long-term problem for salmon farmers in Australia and has become a significant problem in Scotland and Norway.
As part of a project co-funded by Innovate UK and the U.K.'s Biotechnology & Biological Sciences Research Council, researchers at Hendrix Genetics and The Roslin Institute in Scotland have been investigating AGD resistance and applying genomic selection to help tackle the disease.
Alastair Hamilton, head of genomics at Hendrix Genetics Aquaculture BV, introduced standard sampling collection for both genetic and immunological analysis and has now implemented genomic selection for resistance.
"We started dedicated challenges of all elite families in closed conditions in 2015, and our initial results showed a moderate to high heritability. The trait is clearly highly polygenic, so (it is) a textbook case for the application of genomic selection," Hamilton said.
Dr. Ross Houston, group leader in aquaculture genetics at The Roslin Institute and key collaborator on this project said, "Selective breeding for AGD resistance has been underway for several generations in Australia, where a reduction in treatment frequency of around 12% per generation has been achievable. Our research has shown that genomic selection will markedly improve the rate of genetic progress in selective breeding for disease resistance compared to family-based approaches. Therefore, our collaboration will have positive financial and animal welfare implications by reducing the potential negative impact of AGD outbreaks."
The Roslin Institute is also investigating the biology underlying genetic resistance to AGD in salmon through a Royal Society Newton International Fellowship that was recently awarded to Dr. Diego Robledo, who will work in Houston’s lab to understand the difference in patterns of gene expression between AGD-resistant and AGD-susceptible salmon.