Abstract
This study was aimed to evaluate the effects of partial replacement of fish meal by fermented moringa leaves (FMLs) on growth performance, serum biochemistry, antioxidant status, nonspecific immunity, and resistance against Aeromonas hydrophila in juvenile gibel carp (Carassius auratus gibelio var. CAS III). Four isonitrogenous and isoenergetic balanced diets, including three FML diets (substituting 20%, 40%, 60% of the fish meal in basal diet, F20, F40 and F60, respectively) and a basal diet (a diet containing 10% fish meal) were used. Each diet was randomly allocated to four fish groups (F20, F40, F60 and control) reared in a recirculating system. After 50 days of the feeding trial, fish were challenged by A. hydrophila. The result revealed that final mean body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), feed efficiency (FE) and survival rate (SR) were significantly increased (P < 0.05) in F20 and F40 groups compared with the control group. Decreased hepatosomatic index (HSI), body crude lipid, serum aspartate transaminase (AST) and serum alanine aminotransferase (ALT) activities, and increased serum alkaline phosphatase (AKP) and serum glutathione peroxidase (GPx) activities were observed in F40 and F60 groups compared with the control and F20 groups. All FMLs-supplemented groups increased (P < 0.05) serum superoxide dismutase (SOD), catalase (CAT) and lysozyme activities, complement component 3 (C3) and serum immunoglobulin M (IgM) concentration, or decreased serum malondialdehyde (MDA) and protein carbonyl (PCC) contents (P < 0.05). After the challenge test, the significant downregulation of toll-like receptors2 (TLR2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-8 mRNA transcription levels was observed in spleens of FMLs supplemented groups. Dietary F40 and F60 showed higher (P < 0.05) relative percent survival (RPS) (48.72% and 43.59%, respectively) against A. hydrophila infection than control. These results indicate that, as a dietary fish meal substitute, FMLs enhance the growth, and antioxidant and immune response, and regulate the expression of immune-related genes and increase disease resistance against A. hydrophila via TLR2 pathway in gibel carp, with greatest effects of 40% fish meal substitution.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.