Resistance to vibriosis in Atlantic cod (Gadus morhua L.): First challenge test results

The objective of this study was to assess between-family differences in resistance to vibriosis in Atlantic cod. Twenty full-sib families, of which 13 were of Norwegian coastal cod (CC) and 7 families represented northeast Arctic cod (NEAC), were tested for survival after challenge with Vibrio anguillarum. Mortality after challenge was recorded daily, and the experiment was terminated 22 days post challenge. The overall survival at the end of the experiment was 12.3%. Significant family differences in the survival patterns were found both at the end of the test and 8 days after challenge (approximating 50% mortality). In this study, CC (14.2% survival) proved to be more resistant to vibriosis than NEAC (8.6% survival). Although further investigations are needed to quantify the amount of additive genetic variation in vibriosis resistance, this study gives an indication that challenge test results may successfully be used as selection criteria for disease resistance to classical vibriosis in Atlantic cod.