| The effects of Lactobacillus helveticus and Tetraselmis suecica on growth performance and immune system against Aeromonas hydrophila Infection in Zebrafish (Danio rerio) |
| Paper ID : 1027-ICIAQUA |
| Authors |
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Hanieh Mohammadyari *1, Delaram Eslimi-Esfahani1, Ehsan Ahmadifar2, Mehdi Ahmadifar1 1Department of Animal Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran 2Department of Fisheries, Faculty of Natural Resources, University of Zabol, Zabol, Iran |
| Abstract |
| Purpose: This study investigated the individual and combined effects of the dietary Tetraselmis suecica (TS) and Lactobacillus helveticus (LH) on the growth performance, immune responses and disease resistance in zebrafish (Danio rerio). Method: A total of 240 fish (body weight of 5.03 ± 2.4 g) were randomly distributed in 12 tanks with 20 fish per tank (4 treatments with 3 replications) and fed with diets containing 0% LH and TS (T1), 108 CFU/g LH (T2), 15 g/Kg TS (T3) and combination of 108 CFU/g LH and 15 g/Kg TS (T4). Result: After 45 days, weight gain and specific growth rate were increased, and feed conversion ratio decreased in T4 treatment compared to other groups (P<0.05). The challenge test with A. hydrophila revealed that zebrafish fed with a combination of LH and TS had a lower mortality rate than the control. The results also showed that the activity of protease, amylase and lipase in T4 group was significantly higher than other groups (P<0.05). The mixture of LH and TS improved Superoxide dismutase (SOD), glutathione peroxidase (GPX), and malondialdehyde (MDA). The expression of catalase (CAT) and lysozyme genes were upregulated in T4 treatment. The mRNA levels of lysozyme, IL6, IL-1β, IL-8, TGF, and TNF-α transcription were higher in fish fed with both LH and TS (P < 0.05). Conclusion: The mixture of LH and TS is more effective than using each individually for improving the growth performance, antioxidative capacity, and disease resistance against A. hydrophila infection by stimulating the zebrafish immune system. |
| Keywords |
| Dietary supplementation, Immune parameters, Growth performance, Probiotics |
| Status: Abstract Accepted (Oral Presentation) |