m.a.khalifa. amal

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 (20±5 g) were randomly allocated into three groups and fed diets containing varying amounts of dried lemon pomace powder (0[control], 1, and 2%) for 10 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 14%, and its virulence genes (cds1, qse C, and pvsA) were detected using PCR. It was observed that 1 or 2% of lemon pomace dietary addition improved productive performance compared to control. Also, 1 or 2% 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, 1 or 2% 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 (80%) with the lowest mortality (20%), morbidity (56.6%), and re-isolation (30%) rates after E. tarda infection was observed in the group fed a diet containing 2.0% lemon pomace followed by 1.0% lemon pomace group, while the worst rates were recorded in the control fish.