Studies on plant based dietary supplements for control of Aeromonas hydrophila infections in rainbow trout (Oncorhynchus mykiss Walbaum)

Rainbow trout (Oncorhynchus mykiss Walbaum) of average weight 18 g, were fed for two weeks with diet supplemented with 0.5 g (= 0.5%), 1 g (= 1%) and 2 g (= 2%) 100 g-1 of lupin (Lupinus perennis), mango (Mangifera indica) and stinging nettle (Urtica dioica), and with normal diet as controls. Following challenge with Aeromonas hydrophila, there was a reduction in mortality compared with the controls. Furthermore, the fish, which were fed with dietary supplements, recorded enhanced haematological and immunological parameters including phagocytic, respiratory burst, lysozyme, bactericidal, complement, myloperoxidase and antiprotease activities, and total protein, compared to the controls. Feeding for 2 months with 1% and 2% of the dietary supplements led to an increase in growth performance, body composition, digestive enzyme (total proteases, amylase, lipase and pepsin), total protein and glucose compared to controls, whereas there was not any effect on kidney or liver function. The expression of IL-1ß, IL-8 and TGF- ß1 in head kidney of rainbow trout fed for 2 months was upregulated after feeding with 1% lupin and 1% stinging nettle. In contrast, there was not any significant effect following feeding with mango.EThOS - Electronic Theses Online ServiceGBUnited Kingdo