| Effects of dietary yeast culture on innate immune responses and antibacterial capacity of plasma and skin mucus of rainbow trout |
| Paper ID : 1118-ICIAQUA (R1) |
| Authors |
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Seyyed Morteza Hoseini *1, Morteza Yousefi2, Olga Alexandrovna Novichevskaya3, Diana Andreevna Sulina3, Maria Igorevna Dashko3 1Inland Waters Aquatics Resources Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research, Education and Extension Organization, Gorgan, Iran 2RUDN University, 6 Miklukho-Maklaya St, Moscow, 117198, Russian Federation 3RUDN University, Moscow, Russia |
| Abstract |
| Purpose: improvement of fish innate immunity is a practical method of suppressing the risk of disease outbreaks. Probiotics are known as one of the best immunostimulants and yeast, Saccharomyces cerevisiae is one of the most-used one in aquaculture. This study aimed at assessing the effects of dietary yeast culture on innate immune parameters and bactericidal activities in rainbow trout, Oncorhynchus mykiss. Method: rainbow trout juveniles (~10 g) were assigned to three treatments, each consisting three tanks, stocked with 10 fish. They were allowed to acclimatize to the experimental conditions for 7 days, during which they were fed a commercial diet. Then, they were fed either the commercial diet or commercial diet supplemented by 1 × 107 CFU/g (Y7) or 1 × 108 CFU/g (Y8) yeast culture for 30 days. Then, blood leukocyte, plasma/mucus lysozyme, alternative complement (ACH50) activities and bactericidal activities against Aeromonas hydrophila, Streptococcus iniae and Yersinia ruckeri were assessed. The data were analyzed by one-way ANOVA and Duncan tests. Results: there was no significant difference in growth performance and feed efficiency among the treatments (P<0.05). Both Y7 and Y8 treatments exhibited significant (P<0.05) elevations in plasma lysozyme and bactericidal activity against S. iniae, and mucus bactericidal activity against A. hydrophila, compared to the control. The Y7 treatment also had significantly (P<0.05) higher mucus lysozyme and bactericidal activity against Y. ruckeri. On the other hand, dietary treatments exhibited no significant differences in the blood leukocyte count, lymphocyte, neutrophil and monocyte percentages, and plasma/mucus ACH50 activity. Conclusions: based on the present results, a short-term dietary yeast supplementation is beneficial to augment lysozyme and bactericidal activity in plasma and mucus of rainbow trout, which may mitigate the bacterial-associated mortality. |
| Keywords |
| Diet, Probiotic, Blood, Skin mucus, Pathogenic bacteria. |
| Status: Abstract Accepted (Oral Presentation) |