On-farm performance of rainbow trout (Oncorhynchus mykiss) selectively bred for resistance to bacterial cold water disease: Effect of rearing environment on survival phenotype

► Three selectively bred rainbow trout lines differ in resistance to BCWD. ► Trout lines stably express their phenotypes during growth and after transport. ► Following on-farm BCWD outbreak, ARS-Fp-R (resistant) line showed greater survival. ► Magnitude of survival phenotype difference was sensitive to environmental influence.