ICAR-Central Institute of Fisheries Education, Mumbai, 400061, India.
ICAR-Central Marine Fisheries Research Institute, Mumbai Centre, Mumbai, 400061, India.
Sci Rep. 2023 Jul 13;13(1):11345. doi: 10.1038/s41598-023-38267-7.
Species diversification from major to minor carps for their sturdiness and initial higher growth, and also a quest for antibiotic-free aqua farming in the subcontinent, mandates search for and evaluation of alternatives. An experiment was performed to investigate the potential of fructooligosaccharide (FOS) and Bacillus subtilis (BS) (alone or as synbiotics) in promoting growth and immunity against infections in Labeo fimbriatus fingerlings. Six iso-nitrogenous and iso-lipidic diets containing combinations of two levels of FOS (0% and 0.5%) and three levels of BS (0, 10, 10 CFU/g feed) were fed to fish for 60 days. At the end of the feeding trial, twenty-four fish from each group were injected intra-peritoneally with pathogenic strain of Aeromonas hydrophila O:18 to test the immunoprotective efficacy of the supplements against bacterial infection. BS, but not FOS, significantly improved (P < 0.05) growth and feed utilisation attributes like percentage weight gain (PWG), specific growth rate (SGR) and feed conversion ratio (FCR). There were interactive effects of FOS and BS on PWG, SGR and FCR; however, the effects were not additive in nature. These beneficial effects of BS, alone or in combination with FOS, were corroborated by increased protease activity, microvilli density and diameter and number of goblet cells. Overall beneficial effects of FOS and BS included improved erythrocyte (RBC), hemoglobin (Hb), total protein and globulin levels. Total leucocyte (WBC) count and immunological parameters like respiratory burst activity of leucocytes (NBT reduction), lysozyme activity, albumin: globulin ratio and post-challenge survival were significantly improved by both FOS and BS, and their dietary combination yielded the highest improvement in these parameters. Synergistic effects of FOS and BS as dietary supplements indicate that a combination of 10 CFU/g BS and 0.5% FOS is optimal to improve growth, feed utilisation, immune functions, and disease resistance in L. fimbriatus fingerlings.
为了提高鱼类的抗逆性和初始生长速度，从小型鱼类向大型鱼类进行品种选育，同时追求在南亚次大陆实现无抗生素水产养殖，因此需要寻找和评估替代抗生素的方法。本研究旨在探索低聚果糖（FOS）和枯草芽孢杆菌（BS）（单独或作为合生元）在促进侧纹唇鱼仔鱼生长和抗感染免疫方面的潜力。将含有两种 FOS 水平（0%和 0.5%）和三种 BS 水平（0、10 和 10 CFU/g 饲料）的六种等氮等脂饲料喂养侧纹唇鱼仔鱼 60 天。在喂养试验结束时，从每组中选择 24 条鱼，通过腹腔注射致病性嗜水气单胞菌 O:18 来测试补充剂对细菌感染的免疫保护效果。BS 而不是 FOS 显著提高了（P<0.05）生长和饲料利用特性，如增重百分比（PWG）、特定生长率（SGR）和饲料转化率（FCR）。FOS 和 BS 之间存在互作效应，但这种互作效应不是累加的。BS 单独或与 FOS 联合使用可提高蛋白酶活性、微绒毛密度和直径以及杯状细胞数量，从而产生这些有益效果。FOS 和 BS 的整体有益效果包括提高红细胞（RBC）、血红蛋白（Hb）、总蛋白和球蛋白水平。FOS 和 BS 均可显著提高总白细胞（WBC）计数和免疫参数，如白细胞呼吸爆发活性（NBT 还原）、溶菌酶活性、白蛋白:球蛋白比值和攻毒后存活率。FOS 和 BS 作为膳食补充剂的协同作用表明，BS 10 CFU/g 和 FOS 0.5% 的组合是提高侧纹唇鱼仔鱼生长、饲料利用、免疫功能和抗病能力的最佳选择。
