PDF(Pubmed)
Abstract：
An eight-week feeding trial was conducted to investigate the effects of a dietary β-glucan application strategy on the growth performance, physiological response, and gut microbiota of Pacific white shrimp (Litopenaeus vannamei) (0.49 ± 0.17 g) under low salinity. Six feeding strategies were established, including a continuous β-glucan-free diet group (control), a continuously fed group with a 0.1% β-glucan diet (T1), and groups with the following intermittent feeding patterns: 1 day of β-glucan diet and 6 days of β-glucan-free diet (T2), 2 days of β-glucan diet and 5 days of β-glucan-free diet (T3), 3 days of β-glucan diet and 4 days of β-glucan-free diet (T4), and 4 days of β-glucan diet and 3 days of β-glucan-free diet (T5) each week. No significant differences in growth performance among all the groups were found, although the condition factor was significantly higher in the T3 group than in the T1 and T5 groups (p < 0.05). The T-AOC and GPX activities were significantly lower in the T3 group than in the control group (p < 0.05). The MDA content was also significantly lower in the T2 group than in the T3 and T4 groups (p < 0.05). Additionally, the mRNA expression of the Pen3a gene was significantly upregulated in the hepatopancreas of the T4 group compared to the control and T5 groups (p < 0.05), and the Toll gene was also significantly upregulated in the T3 group compared to the T1 and T2 groups (p < 0.05). Dietary β-glucan induced changes in the alpha diversity and composition of the gut microbiota in different feeding strategies. The beta diversity of the gut microbiota in the T2 group was significantly different from that in the control group. The results of a KEGG analysis showed that gut function in the carbohydrate metabolism, immune system, and environmental adaptation pathways was significantly enhanced in the T3 group. These findings provide evidence that the intermittent feeding strategy of β-glucan could alleviate immune fatigue, impact antioxidant ability, and change gut microbiota composition of L. vannamei under low salinity.
摘要：
进行了为期八周的饲喂试验，以研究日粮β-葡聚糖施用策略对生长性能的影响，生理反应，低盐度下太平洋白虾(凡纳滨对虾)的肠道菌群(0.49±0.17g)。建立了六种喂养策略，包括连续无β-葡聚糖饮食组（对照），含0.1%β-葡聚糖饮食(T1)的连续饲喂组，和具有以下间歇喂养模式的组：1天的β-葡聚糖饮食和6天的无β-葡聚糖饮食（T2），2天的β-葡聚糖饮食和5天的无β-葡聚糖饮食（T3），3天的β-葡聚糖饮食和4天的无β-葡聚糖饮食（T4），和每周4天的β-葡聚糖饮食和3天的无β-葡聚糖饮食(T5)。各组间生长性能无显著差异,尽管T3组的病情因素明显高于T1和T5组（p<0.05）。T3组T-AOC和GPX活性显著低于对照组(p<0.05)。T2组MDA含量也显著低于T3和T4组(p<0.05)。此外,与对照组和T5组相比，T4组的肝胰腺中Pen3a基因的mRNA表达明显上调（p<0.05），与T1和T2组相比,T3组的Toll基因也显著上调(p<0.05)。膳食β-葡聚糖在不同喂养策略中诱导肠道微生物群的α多样性和组成的变化。T2组肠道菌群β多样性与对照组差异显著。KEGG分析的结果表明，碳水化合物代谢中的肠道功能，免疫系统,T3组环境适应途径显著增强。这些发现提供了证据，β-葡聚糖的间歇喂养策略可以缓解免疫疲劳，影响抗氧化能力，并改变低盐度条件下凡纳滨对虾肠道菌群组成。
