Evaluating the effects of dietary intake of encapsulated Lactobacillus plantarum KC426951 on growth, survival rate, blood and serum factors and gut bacterial flora of Rainbow trout (Oncorhynchus mykiss)

Document Type : Research Paper

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Abstract

In this study, the effects of Lactobacillus plantarum KC426951 on growth, survival rate, blood and serum factors and gut bacterial flora of rainbow trout were investigated. For this purpose, 90 fish with an average weight of 12.94±0.35 g were fed for 8 weeks with the diets containing different amounts of encapsulated Lactobacillus plantarum including treatment 1 (107 CFU/g), treatment 2 (108 CFU/g) and the control treatment without Lactobacillus plantarum (T0). The results of this study showed that the highest weight gain, percent of body weight gain, specific growth rate and the lowest feed conversion rate were observed in the treatments 1 which were significantly different as compared to those of the control treatment (P<0.05). However, the amounts of survival rates were not significantly different among various treatments (P>0.05). In blood factors, the numbers of white blood cells in the treatments containing bacteria were significantly higher than the control treatment (P<0.05). The amount of neutrophil in the treatment 1 was lower than that of the other treatments, whereas the amount of lymphocyte in the treatment 1 was higher than that of the other treatments (P<0.05). The amount of monocyte in the treatment 2 was significantly higher than that of the treatment 1 (P<0.05). The levels of glucose, triglyceride, cholesterol, LDL, AST and ALP were significantly higher in the treatment 1 than those of the other treatments. The amount of total protein in the treatment 1 was significantly higher than that of the treatment 2 (P<0.05). But there were not significant differences among various treatments in other blood parameters (P>0.05). According to the results, the numbers of lactic acid bacteria in the treatments containing bacteria (1 and 2) were significantly higher than the control treatment. The total bacterial count in the treatment 1 was significantly higher than that of the other treatments (P<0.05). Therefore, the addition of 107 CFU/g of encapsulated Lactobacillus plantarum bacteria to fish diet could have positive effects on the growth and health parameters of rainbow trout.
 

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