Tannins have great potential as an alternative to in-feed antibiotics. However, no study has investigated the effects of tannins on shrimp. The present study assessed the eff ;ects of hydrolyzable tannins (HTs) fed at different inclusion levels (F0: control, F0.5: 0.05 %, F1: 0.1 %, F1.5: 0.15 % and F2: 0.2 % (g⁻¹ feed) on the growth performance, antioxidant capacity, immune response, intestinal microflora and resistance to Vibrio parahaemolyticus of juvenile Pacific white shrimp (Litopenaeus vannamei). After 60 days of the feeding trial, a significant increase (P < 0.05) of weight gain rate (WGR), specific growth rate (SGR), activities of alkaline phosphatase (ALP), acid phosphatase (ACP), superoxide dismutase (SOD) and trypsin in serum and hepatopancreas, and the expression level of catalase (CAT), Cu/Zn superoxide dismutase (Cu/Zn-SOD) and glutathione peroxidase (GPx) gene in the hepatopancreas of 0.15 % HT treated groups were achieved. The dietary supplementation of HTs also changed the composition of intestinal microflora. At the phylum level, Proteobacteria accounted for the majority of bacteria, followed by Firmicutes, Bacteroidetes and Actinobacteria. At the genus level, Stenotrophomonas, Ruegeria, and Photobacterium were dominant in the F0.5, F1, and F1.5 groups, respectively. The relative abundance of Vibrio and Carboxylicivirga decreased in the intestines of shrimp fed with HTs diets. Furthermore, F1.5 group showed the highest relative percent survival value (80 %) (P < 0.05), which indicates that the supplementation of 0.15 % HTs in challenge test significantly enhanced the resistance of shrimp against V. parahaemolyticus infection after 24 h. These results indicated that 0.15 % HTs could remarkably improve the growth performance, antioxidant capacity, intestinal microflora, and resistance against V. parahaemolyticus of L. vannamei, and can be a potential feed additive for shrimp in aquaculture. According to our study, the optimal dietary supplementation dosage of HTs is 0.15 % feed in diets.

单宁酸具有替代饲料中抗生素的巨大潜力。但是，没有研究调查单宁酸对虾的影响。本研究评估了在不同夹杂物含量下饲喂的可水解单宁（HTs）的效果（F0：对照，F0.5：0.05％，F1：0.1％，F1.5：0.15％和F2：0.2％（g ^{− 1种}饲料）对太平洋小白虾（凡纳滨对虾）的生长性能，抗氧化能力，免疫反应，肠道菌群和对副溶血弧菌的抵抗力。饲喂试验60天后，显着增加（P体重增加率（WGR），比生长率（SGR），碱性磷酸酶（ALP），酸性磷酸酶（ACP），超氧化物歧化酶（SOD）和胰蛋白酶在血清和肝胰腺中的活性以及过氧化氢酶的表达水平<0.05） （CAT），0.15％HT处理组的肝胰腺中获得了Cu / Zn超氧化物歧化酶（Cu / Zn-SOD）和谷胱甘肽过氧化物酶（GPx）基因。HTs的饮食补充也改变了肠道菌群的组成。在门级，变形杆菌占大多数细菌，其次是硬毛菌，拟杆菌和放线菌。在属水平上，嗜麦芽窄食单胞菌，Ruegeria和发光细菌分别在F0.5，F1和F1.5组中占主导地位。的相对丰度饲喂HTs日粮的虾肠中弧菌和Carboxylicivirga含量下降。F1.5组的相对存活率最高（80％）（P <0.05），说明在攻击试验中补充0.15％HTs可以显着增强虾24h后对副溶血弧菌的抵抗力。这些结果表明，0.15％HTs可以显着改善南美白对虾的生长性能，抗氧化能力，肠道菌群和对溶血弧菌的抗性。，并且可以作为水产养殖虾的潜在饲料添加剂。根据我们的研究，HTs的最佳膳食补充剂量为日粮中0.15％的饲料。