Vitamin E and selenium prophylaxis against “Hitra disease” in farmed Atlantic salmon — a survival study

Abstract

Effects of a parenteral administration of selenium, vitamin E or a combination of the two on the survival of Atlantic salmon with subclinical “Hitra disease” were compared using survival curves and related hypotheses-testing methods. The median survival time, i.e. the point when 50% of the individuals are dead, was 34 days in the Se group, 38 days in the vitamin E group, 31 days in the Se+vitamin E group, and 28 days in the control group which received only a placebo. Differences between the groups did not reach statistical significance; even when testing the vitamin E group against the control group the P value was about 15%. Thus, treatments did not prevent mortalities in salmon with subclinical “Hitra disease”.