Rearing temperature’s effect on the growth performance, nutrient utilization and immune response of growth hormone transgenic female triploid Atlantic salmon (Salmo salar)

This thesis examined the effect of rearing temperature on AquAdvantage Salmon (AAS; growth hormone transgenic female triploid Atlantic salmon) reared at 10.5°C, 13.5°C, 16.5°C from first feed to 1500 g. Fish reared at 16.5°C reached 1500 g in the shortest amount of time, however, thermal-unit growth coefficient (TGC) results showed that salmon reared at 10.5°C exhibited higher growth rates for most of the trial. Through analysis of whole-body and fillet samples at various growth stages, it was determined that rearing temperature significantly influenced composition, deposition rates and retention efficiencies of numerous nutrients. For example, AAS reared at 16.5°C diverted lipid storage away from muscle tissue into their viscera and were less efficient at retaining important nutrients, such as omega-3 fatty acids. By assessing the antiviral immune gene expression response of fish injected with polyriboinosinic polyribocytidylic acid (pIC), it was concluded that temperature significantly influenced immune responses of AAS. Based on transcript expression responses, as measured by real-time quantitative polymerase chain reaction (qPCR) analysis, it appeared that a more robust immune response was mounted by fish reared at 10.5°C compared to 16.5°C. Collectively, these results help establish foundational knowledge that can guide future research to optimize commercial rearing of AquAdvantage Salmon