Pioneering science applied to PD and sea lice resistance

This method is already recognized in genetic science for other species, and can provide a more accurate and safer selection than by using traditional methods, according to Benchmark Holdings, the company that owns SalmoBreed.

Benchmark believes that the use of this method can provide a significant advancement in developing resistance to both PD and sea lice in salmon, and thus provide significant savings for the industry.

SalmoBreed's geneticists have been very satisfied with the accuracy of the results achieved from this new method thus far. It has long been proven that genomic selection provides increased genetic gain and reduced rate of inbreeding in species such as cattle, pigs and poultry. For the first time, SalmoBreed can implement this technology in salmon breeding as well, initially for PD and sea lice resistance. Through genomic selection the selection of parent broodfish is based on both phenotypic data (the physical expressions of a desired trait) and information from a large number of DNA-markers. In the case of PD and sea lice resistance, SalmoBreed utilizes approximately 50,000 DNA-markers (called SNPs).

PD resistance

When breeding for PD resistance, SalmoBreed has previously used family information from challenge tests and Quantitative Trait Loci (QTL) testing, which relies on correlations or trends between genes from a limited segment on the genome, resulting in a potentially significant genetic variation of the desired trait. By using genomic selection instead of QTL, the company looks at the whole genome of the fish and can thus access a more complete picture of how the genetic architecture looks for the desired trait, resulting in a more accurate selection of broodstock.

Sea lice resistance

When addressing sea lice resistance, SalmoBreed has previously developed genetic ranking based on family information from challenge tests. This meant distinction was only possible between families, without knowledge of the characteristics of the individual broodstock within each family. With genomic selection, it is possible to select those individuals showing the highest resistance to sea lice within each separate family, and hence get a stronger assurance that the eggs supplied have the desired genetic value of the trait of interest.

Genetic selection allows for the selection of the best individual broodstock from all families, with the resulting increase in genetic progress and reduced rate of inbreeding creating a more sustainable breeding program. This means it will be possible to reduce the number of artificial sea lice treatments in the sea and result in future cost savings. The presence of fewer lice treatments is important for fish welfare, environment and working environment.

This is not only a breakthrough for Benchmark, but also for the entire salmon industry, which will have the opportunity to make use of the results from salmon fry already produced this autumn. Whilst definitive results in terms of efficacy are yet to be established, this advance in technology and method signals a step change in the salmon breeding industry, both in terms of efficiency and animal welfare.

The R&D leading to the application of genomic selection in salmon was conducted in cooperation with Nofima and other partners through an innovation project supported by the NFR (The research council of Norway). Further development of the method for implementation in the company's breeding program is being performed in cooperation with Nofima and Akvaforsk Genetic Center (AFGC), a sister company of SalmoBreed within Benchmark's Breeding and Genetics division.

"We are very proud of our success in adopting genomic selection for two important traits in our breeding program," said SalmoBreed's CEO, Dr Jan-Emil Johannessen.