Phytogenics from sage and lemon verbena promote growth, systemic immunity and disease resistance in Atlantic salmon (Salmo salar)

Deciphering the dietary immunomodulatory effects of a feed additive rich in verbascoside and triterpenic compounds like ursolic (MPLE, NATAC Biotech SL, Spain) on the systemic immune response and disease resistance of Atlantic salmon (Salmo salar L.) smolts. Transcriptomic analysis was conducted in order to determine the differences on gene expression level between these two dietary strategies at head kidney specific level. The experimental design included two conditions: (1) fish fed basal diet with no phytogenic feed additives (MPLE) (control); (2) fish fed 0.1% inclusion of MPLE (10%, ursolic acid, 3% other triterpenic compounds; 2% verbascoside and <1% polyphenols) from sage and lemon verbena. After 133 days of feeding trial, total RNA were extracted invidually from Atlantic salmon (S. salar) head kidney fed basal diet or an experimental diet containing 0.1% inclusion. Total RNA samples were grouped into 3 pools (n= 6 fish for each condition). The transcriptomic analysis was done following a reference design using the control diet group as reference.