Effects of adding dietary Lactobacillus plantarum on efficient performance of soybean meal in the rainbow trout (Oncorhynchus mykiss) hematological and immune indices

Dabbagh, Asal; Ouraji, Hossein; Keramat Amirkolaie, Abdolsamad; Ansari, Zarbakht

doi:10.22124/janb.2023.22385.1169

Effects of adding dietary Lactobacillus plantarum on efficient performance of soybean meal in the rainbow trout (Oncorhynchus mykiss) hematological and immune indices

Document Type : Research Paper

Authors

¹ Department of Fisheries, Faculty of Animal Sciences and Fisheries, Sari Agricultural Sciences and Natural Resources University, Sari, Mazandaran, Iran

² Department of Animal Science, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Resources University, Sari, Mazandaran, Iran

10.22124/janb.2023.22385.1169

Abstract

In the present study, the effects of probiotic (0 and 1) in rainbow trout fed with different levels of soybean meal (SBM; 0, 20 and 40%) were evaluated on hematological and immune indices. A total of 300 fry with average initial weight of 20.05 ± 0.20 g by density of 25 fish per tank assigned to 12 tanks for 90 days. Blood was taken from fish on days 0, 45 and 90, afterward hematological and immune indices were estimated. According to hematological results in day 45, fish fed with SBM 0 demonstrated greatest number of white blood cells and hematocrit among treatments (p < 0.05). In day 90, the highest number of red blood cells was found in SBM 0 and SBM 20% containing probiotic (p < 0.05). Number of white blood cells significantly increased by adding probiotic to different SBM levels (p < 0.05). Hematocrit and hemoglobin concentrations decreased in fish fed with SBM 40% (p < 0.05). In addition, there were interaction between SBM × probiotic in white blood cells on day 90 (p < 0.05). According to immunological results in day 45, neutrophil burst activity (NBT) was elevated by adding probiotic to SBM levels (p < 0.05). The IgM and C₃ levels were significantly enhanced by adding probiotic to SBM 0 and SBM 20%. In day 90, the highest NBT value was observed in SBM 0 (probiotic 0 and 1) and SBM 20% containing probiotic among groups (p < 0.05). Addition of probiotic to SBM 0 and SBM 20% caused the elevated lysozyme, IgM, C₃ and C₄ values (p < 0.05). Furthermore, interaction between SBM levels and probiotic indicated significant effects on NBT after 90 days (p < 0.05). It could be revealed from the current study that L. plantarum compensated some adverse effects of SBM replacement on blood and immune indices by enhancing immunity, hence higher replacement of SBM is not suggested without using probiotic.

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