Investigation into the potential use of dietary supplementation to reduce the impact of Amoebic Gill Disease

Abstract

Amoebic Gill Disease (AGD) is a disease affecting cultured Atlantic salmon (Salmo salar) which is caused by Paramoeba perurans. The immunomodulatory impact of functional foods has previously been demonstrated in salmon. The aim of this study was to investigate the role of a novel fish feed in mitigating the severity and progression of AGD in Atlantic salmon.

Negative and positive control fish were maintained on a base fish feed, with experimental fish maintained on a customized feed blend pre- and post-amoeba inoculation. Disease progression was evaluated using gill scoring and diagnostic quantitative real-time polymerase chain reaction (qPCR) for the detection of P. perurans at 14 and 21 dpi. The expression profiles of 11 immune related genes were analyzed by qPCR at 14 and 21 dpi. The customized feed blend was shown to delay the onset of clinical symptoms associated with AGD. Furthermore, the expression of genes with roles in maintenance of the mucosal layer and mucosal defense were impacted in fish fed on this novel feed formulation.