Estimation of the Heritability for Resistance to Infectious Hematopoietic Necrosis in Rainbow Trout

Abstract

A hierarchical breeding design was used to estimate the heritability for resistance to infectious hematopoietic necrosis in reared rainbow trout Oncorhynchus mykiss. The juveniles were exposed to IHNV by a dipping method with doses of 10^2.55 and 10^3.55 TCID₅₀/ml.
The heritability (h_s²) in 10^2.55 and 10^3.55 challenges were estimated to be 0.05 and 0.51, respectively. Resistance against the challenge with the higher dose could be increased by artificial individual selection because of high heritability. On the other hand, low mortality and heritability indicated that the resistance against the challenge with the lower dose could not be increased.