Strong proof of concept

PRODUCTION of large Rainbow trout in salty or brackish environments has always been associated with the risk of vibriosis ( V.anguillarum), with vaccination being the only protective measure so far. Now, however, it has been shown that natural resistance to vibriosis is heritable and can be selected for in the breeding, as well as production, of commercial egg batches.

The University of Copenhagen, in collaboration with AquaSearch, has identified a DNA loci (QTL) highly correlated with the survival of FISH during a vibriosis challenge trial. Further, fingerlings produced using males homozygotic to this QTL had a 68.8 % better survival relative to controls (RPS), equal to what would generally be considered “vaccination level protection”!