Genetic variation in resistance to infectious pancreatic necrosis in rainbow trout (Oncorhynchus mykiss) after a challenge test

Abstract

In this study, we wanted to evaluate genetic variation in resistance to infectious pancreatic necrosis (IPN) in a breeding population of rainbow trout. Two hundred families were challenged at a commercial test station, using methods that were previously developed for testing resistance to IPN in Atlantic salmon. Thirty-¢ve days after the challenge the accumulated mortality was 26%. The results show that resistance to IPN is moderately heritable in the tested population (h 2 50.30). The genetic correlation between IPN resistance and body weight was found to be low and non-signi¢cant. The signi¢cant additive genetic variation found in IPN resistance after a controlled challenge test gives promise for successful breeding for increased resistance to IPN in rainbow trout.