Shija Vicent Michael, Zhimin Ju, Chen Huapu, Amoah Kwaku, Li Yi, Ng'onga Lishuko, Ndandala Charles Brighton, Zhong Yong, Masanja Fortunatus, Huang Junwei, Cai Jia
Shenzhen Institute of Guangdong Ocean University, Shenzhen, 518120, China; College of Fishery, Guangdong Ocean University, Zhanjiang, 524088, China; Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Zhanjiang, 524088, China; Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang, 524088, China.
College of Fishery, Guangdong Ocean University, Zhanjiang, 524088, China.
Fish Shellfish Immunol. 2025 Jan;156:110042. doi: 10.1016/j.fsi.2024.110042. Epub 2024 Nov 24.
This research work investigated the efficacy of Bacillus amyloliquefaciens AV5 in mitigating the stress effects of stocking densities in Nile tilapia (Oreochromis niloticus). 520 healthy Nile tilapia fingerlings (24.43 ± 1.4g) were randomly allocated to 16 plastic tanks, each with a capacity of 400L. Two stocking densities were tested: low density (37.5 fish/m³) and high density (125 fish/m³) with four treatment groups(low density with a control diet (LDC), high density with a control diet (HDC), low density with a supplemented diet (LDS), and high density with a supplemented diet (HDS)) for 8 weeks. HDC exhibited lower values (P < 0.05) for specific growth rate, final weight, weight gain rate, and specific growth rate than fish fed at LDC, LDS, and HDS. The lowest feed conversion ratio was recorded at the LDS and HDS. There were no significant differences (P > 0.05) in survival rates among treatments. There were no notable disparities (P > 0.05) in the LDC, LDS, and HDS body composition. Antioxidant enzyme activities were greater in LDC, LDS, and HDS than in HDC, while malondialdehyde levels were higher in HDC, and hematology parameters in HDS were improved compared to HDC. Elevated levels (P < 0.05) of phagocytic and lysozyme activity were seen in LDS and HDS. There was no change in glucose levels in HDS and LDC. Nonetheless, cortisol was elevated in HDC compared to LDC, LDS, and HDS. Hence, B. amyloliquefaciens AV5(1 × 10 cfu/g) is a potential probiotic to alleviate HDC-induced stress in O. niloticus.
本研究工作调查了解淀粉芽孢杆菌AV5在减轻尼罗罗非鱼（Oreochromis niloticus）养殖密度应激影响方面的功效。520尾健康的尼罗罗非鱼幼鱼（24.43±1.4克）被随机分配到16个塑料水箱中，每个水箱容量为400升。测试了两种养殖密度：低密度（37.5尾鱼/立方米）和高密度（125尾鱼/立方米），设有四个处理组（低密度对照组饮食（LDC）、高密度对照组饮食（HDC）、低密度补充饮食（LDS）和高密度补充饮食（HDS）），为期8周。与LDC、LDS和HDS组喂养的鱼相比，HDC组的特定生长率、终末体重、增重率和特定生长率较低（P<0.05）。LDS和HDS组的饲料转化率最低。各处理组的存活率无显著差异（P>0.05）。LDC、LDS和HDS组的鱼体组成无显著差异（P>0.05）。LDC、LDS和HDS组的抗氧化酶活性高于HDC组，而HDC组的丙二醛水平较高，与HDC组相比，HDS组的血液学参数有所改善。LDS和HDS组的吞噬活性和溶菌酶活性水平升高（P<0.05）。HDS和LDC组的葡萄糖水平没有变化。然而，与LDC、LDS和HDS组相比，HDC组的皮质醇水平升高。因此，解淀粉芽孢杆菌AV5（1×10cfu/g）是一种潜在的益生菌，可缓解高密度养殖对尼罗罗非鱼造成的应激。
