Research Article: Effect of lemon pomace inclusion on growth, immune response, anti-oxidative capacity, intestinal health, and disease resistance against Edwardsiella tarda infection in Nile tilapia (Oreochromis niloticus)

This trial aimed to investigate the impact of dietary lemon pomace inclusion on growth, immune response, anti-oxidative capacity, intestinal health, and disease resistance against Edwardsiella tarda in the Nile tilapia. The fish weighted (۲۰±۵ g) were randomly allocated into three groups and fed diets containing varying amounts of dried lemon pomace powder (۰[control], ۱, and ۲%) for ۱۰ weeks. After this period, the fish were challenged with E. tarda. The bacterium was isolated from naturally infected fish from fish farms in the Kafr- Elsheikh governorate, Egypt with a rate of ۱۴%, and its virulence genes (cds۱, qse C, and pvsA) were detected using PCR. It was observed that ۱ or ۲% of lemon pomace dietary addition improved productive performance compared to control. Also, ۱ or ۲% of lemon pomace dietary addition reduced serum glucose, cortisol, triglycerides and cholesterol concentrations, while increasing the serum catalase and superoxide dismutase activities and improving phagocytic, lysozyme, and bactericidal activities in a dose-dependent manner compared to the control group. Moreover, ۱ or ۲% of lemon pomace dietary addition increased the length of intestinal villi and goblet cell number in a dose-dependent manner of different intestinal portions compared to the control group. The highest survival (۸۰%) with the lowest mortality (۲۰%), morbidity (۵۶.۶%), and re-isolation (۳۰%) rates after E. tarda infection was observed in the group fed a diet containing ۲.۰% lemon pomace followed by ۱.۰% lemon pomace group, while the worst rates were recorded in the control fish.

کلیدواژه ها:

Nile tilapia ، Lemon pomace powder ، Growth performance ، Immune response ، Edwardsiella tarda