Effect of dietary inactivated Lactobacillus plantarum on growth performance, antioxidative capacity, and intestinal integrity of black sea bream (Acanthopagrus schlegelii) fingerlings

Probiotic supplementation in fish feed is becoming popular as a viable alternative to curb the indiscriminate use of antibiotics in aquaculture. The effect of inactivated Lactobacillus plantarum on growth performance and health related indices of black sea bream (Acanthopagrus schlegelii) fingerlings was studied, using different concentrations of a commercial inactivated L. plantarum product (Immuno-LP20): D1 (control, 0 mg/kg), D2 (100 mg/kg), D3 (200 mg/kg), D4 (400 mg/kg), D5 (800 mg/kg), and D6 (1600 mg/kg). After an eight-week feeding trial during which the diets were fed to triplicate groups of fish (initial weight: 1.58 +/- 0.05 g), D2, D3, and D4 produced fish with significantly higher growth parameters than the control fish (P < 0.05), whilst all fish fed the diets with L. plantarum had significantly improved feed utilization parameters than the control group. Serum total protein content, and lysozyme activity significantly increased in fish fed D4 than the control fish, whilst complement 4 content was higher in fish fed almost all the inactivated probiotic diets (except D5) than the control fish. Serum superoxide dismutase activity was significantly higher in fish fed all the Immuno-LP20 diets except D2, and liver glutathione peroxidase activity in D2, D3, and D4 fish were significantly higher than in the control fish. Intestinal structure was also significantly improved in fish fed the Immuno-LP20 diets. According to these results, using inactivated L. plantarum as dietary supplement could be beneficial in the production of black sea bream at an optimum inclusion rate similar to 100 mg/kg <= 400 mg/kg Immuno-LP20.

Automated summary

The study on the effects of inactivated Lactobacillus plantarum on black sea bream fingerlings showed that supplementation with this probiotic significantly improved growth performance and health-related indices in fish, particularly at an optimal inclusion rate ranging from 100 mg/kg to 400 mg/kg.