The genetics of resistance to infectious pancreatic necrosis virus in rainbow trout unveiled through survival and virus load data

Summary

Infectious Pancreatic Necrosis virus (IPNV) is one of the major threats to the animal welfare and economy of the rainbow trout farming industry. Previous research has demonstrated significant genetic variation for resistance against IPNV. The main objective of the study was to investigate the genetic architecture of resistance against IPNV in rainbow trout fry. To achieve this, 610 rainbow trout fry, from a full factorial mating between 5 sires and 5 dams, were bath challenged with the IPNV isolate (IPNV-AS) from Atlantic salmon reared at a commercial farm. The resistance against IPNV was accessed using three different phenotypes; binary survival (BS), total days survived (TDS) and virus load (VL) recorded on the fish throughout the 40-day challenge test. All fish were genotyped using a 57K Affymetrix SNP array. The IPNV-AS isolate resulted in an overall mortality of 62.1%. The heritability estimates for survival (BS h2 = 0.21 ± 0.06, TDS h2 = 0.25 ± 0.07) and VL traits (h2 = 0.23 ± 0.08) were moderate and ind