This study was to explore the impacts of water-soluble chitosan and mixed probiotics on growth performance, intestinal short-chain fatty acids (SCFAs) and immunity and ammonia resistance in Litopenaeus vannamei. Shrimp were fed one of four experimental diets including basal diet (CON), 0.10% water-soluble chitosan diet (WSC), 0.30% mixed probiotics (MP) and 0.10% water-soluble chitosan +0.30% mixed probiotics (SYN) for 8 weeks. Results showed shrimp fed with dietary MP and SYN diets could significantly improve growth performance and feed utilization in comparison with those of shrimp fed with CON diet (P < 0.05). Acetic acid content was significantly higher in shrimp fed with all supplemented diets compared to that in shrimp fed with CON diet (P < 0.05). Compared to shrimp fed with CON diet, dietary WSC and MP significantly influenced the contents and/or activities of aspartate aminotransferase (AST), total protein (TP), superoxide dismutase (SOD), lysozyme (LZM) in serum, SOD, malondialdehyde (MDA), acid phosphatase (ACP) in hepatopancreas and SOD and MDA in intestine. In addition, the gene expression levels of prophenoloxidase (proPO), penaiedin 3a (Pen-3a), crustin (Crustin), serine proteinase (SP), GPX and SOD in hepatopancreas, were significantly upregulated compared to those in CON diet at some time points (P < 0.05). Significantly higher survival rate in all supplemented diets were observed after ammonia challenge (P < 0.05). Therefore, the above results indicated dietary WSC and MP or SYN could enhance intestinal SCFAs content, stimulated antioxidant capacity and immune response, and increase the ammonia resistance of Litopenaeus vannamei. Besides, the growth performance was also improved by dietary MP and SYN.

这项研究旨在探讨水溶性壳聚糖和混合益生菌对凡纳滨对虾生长性能，肠道短链脂肪酸（SCFA）以及免疫和耐氨性的影响。对虾喂食四种实验饮食之一，其中包括基础饮食（CON），0.10％水溶性壳聚糖饮食（WSC），0.30％混合益生菌（MP）和0.10％水溶性壳聚糖+ 0.30％混合益生菌（SYN），共8种周。结果表明，饲喂MP和SYN日粮的虾与饲喂CON日粮的虾相比，可显着改善生长性能和饲料利用率（P  <0.05）。饲喂所有补充饲料的虾的乙酸含量明显高于饲喂CON饲料的虾的乙酸含量（P <0.05）。与饲喂CON日粮的虾相比，日粮中的WSC和MP显着影响血清，SOD和丙二醛（AST），总蛋白（TP），超氧化物歧化酶（SOD），溶菌酶（LZM）的含量和/或活性。 MDA），肝胰腺中的酸性磷酸酶（ACP）以及肠中的SOD和MDA。此外，与CON饮食相比，在某些时候，前酚中的酚氧化酶（proPO），Penaiedin 3a（Pen-3a），Crustin（Crustin），丝氨酸蛋白酶（SP），GPX和SOD的基因表达水平显着上调。分（P  <0.05）。氨激发后，所有补充饮食中的存活率均显着提高（P <0.05）。因此，上述结果表明，饮食中的WSC和MP或SYN可以提高肠道SCFA含量，刺激抗氧化能力和免疫反应，并提高凡纳滨对虾的耐氨性。此外，饮食MP和SYN还改善了生长性能。