Abstract：
The advancement of the Penaeus vannamei industry in a sustainable manner necessitates the creation of eco-friendly and exceptionally effective feed additives. To achieve this, 720 similarly-sized juvenile shrimp (0.88 ± 0.02 g) were randomly divided into four groups in this study, with each group consisting of three replicates, each tank (400 L) containing 60 shrimp. Four experimental diets were formulated by adding 0, 500, 1000, and 1500 mg kg-1 glycerol monolaurate (GML) to the basal diet, and the feeding trial lasted for 42 days. Subsequently, a 72-h White Spot Syndrome Virus (WSSV) challenge test was conducted. Polynomial orthogonal contrasts analysis revealed that with the increase in the concentration of GML, those indicators related to growth, metabolism and immunity, exhibit linear or quadratic correlations (P < 0.05). The results indicate that the GML groups exhibited a significant improvement in the shrimp weight gain rate, specific growth rate, and a reduction in the feed conversion ratio (P < 0.05). Furthermore, the GML groups promoted the lipase activity and reduced lipid content of the shrimp, augmented the expression of triglyceride and fatty acid decomposition-related genes and lowered the levels of plasma triglycerides (P < 0.05). GML can also enhanced the humoral immunity of the shrimp by activating the Toll-like receptor and Immune deficiency immune pathways, improved the phagocytic capacity and antibacterial ability of shrimp hemocytes. The challenge test revealed that GML significantly reduced the mortality of the shrimp compared to control group. The 16S rRNA sequencing indicates that the GML group can increases the abundance of beneficial bacteria. However, 1500 mg kg-1 GML adversely affected the stability of the intestinal microbiota, significantly upregulating intestinal antimicrobial peptide-related genes and tumor necrosis factor-alpha levels (P < 0.05). In summary, 1000 mg kg-1 GML was proven to enhance the growth performance, lipid absorption and metabolism, humoral immune response, and gut microbiota condition of P. vannamei, with no negative physiological effects.
摘要：
南美白对虾行业的可持续发展需要创造环保和特别有效的饲料添加剂。为了实现这一点，在这项研究中，将720只类似大小的幼虾（0.88±0.02g）随机分为四组，每组由三个重复组成，每个罐（400L）包含60只虾。通过在基础日粮中添加0、500、1000和1500mg·kg-1的单月桂酸甘油酯（GML）来配制四种实验日粮，喂养试验持续了42天。随后，进行72小时白斑综合症病毒(WSSV)攻击试验。多项式正交对比分析表明,随着GML浓度的增加,那些与增长相关的指标，新陈代谢和免疫力，呈线性或二次相关(P<0.05)。结果表明，GML组显示出虾增重率的显着改善，比增长率，饲料转化率降低(P<0.05)。此外，GML组促进脂肪酶活性和降低虾的脂质含量，增加甘油三酯和脂肪酸分解相关基因的表达，降低血浆甘油三酯水平（P<0.05）。GML还可以通过激活Toll样受体和免疫缺陷免疫途径增强对虾的体液免疫，提高了对虾血细胞的吞噬能力和抗菌能力。攻击测试表明，与对照组相比，GML显着降低了虾的死亡率。16SrRNA测序表明GML组可增加有益细菌的丰度。然而,1500mg·kg-1GML对肠道菌群的稳定性产生不利影响，肠抗菌肽相关基因和肿瘤坏死因子-α水平显著上调(P<0.05)。总之,1000mg·kg-1GML被证明可以提高生长性能，脂质吸收和代谢，体液免疫反应，和凡纳滨对虾的肠道微生物群状况，没有负面的生理影响。
