膽固醇(CHO)是甲殼動物一種昂貴的必需營養(yǎng)素。膽汁酸(BAs)作為乳化劑可促進脊椎動物對脂質的吸收，在生長和固醇代謝中起著關鍵作用。本研究通過為期2個月的投喂實驗，旨在探究飼料中添加膽固醇和發(fā)酵膽汁酸(FBAs；一種新型發(fā)酵膽汁酸)對淡水環(huán)境下凡納濱對蝦生長性能、免疫反應及腸道健康的獨立及聯(lián)合效應。實驗共設計了12種等氮等脂飼料，在基礎飼料中分別添加0.04% FBAs(A3)，0.05%(C1)、0.10%(C2)、0.20%(C3)、0.30%(C4)和0.40%(C5)的CHO，以及A3C1、A3C2、A3C3、A3C4和A3C5的FBAs與CHO復合物，并設置不添加FBAs與CHO的對照組(N)。鑒于基礎飼料本身含有0.08%的CHO(來源于魚粉等原料)且未檢測到FBAs，實際CHO水平調整為0.08%(N)、0.13%(C1)、0.18%(C2)、0.28%(C3)、0.38%(C4)和0.48%(C5)。60天后，終末體重、增重率和特定生長率表明，F(xiàn)BAs、CHO及其復合物均能改善對蝦生長性能，其中A3C2和A3C3組效果最佳。雙因素方差分析顯示FBAs與CHO之間存在顯著協(xié)同效應。結果表明，CHO促進生長的效率高于FBAs，但與FBAs聯(lián)用時其效率可顯著提升。血淋巴生化參數(shù)(包括天冬氨酸氨基轉移酶、丙氨酸氨基轉移酶、α-淀粉酶、甘油三酯和酸性磷酸酶)均受不同處理的顯著影響。肝胰腺基因表達水平顯示，各處理組的抗脂多糖因子(ALF)、酚氧化酶原(proPO)和α2-巨球蛋白(α2M)表達顯著降低，而堿性磷酸酶(AKP)表達顯著高于對照組。飼料中添加FBAs、CHO及其復合物提高了凡納濱對蝦腸道菌群多樣性。在門水平上，與對照組相比，變形菌門豐度顯著降低，厚壁菌門、軟壁菌門和藍藻菌門豐度顯著增加。在屬水平上，F(xiàn)BAs與CHO處理組的假交替單胞菌屬弧菌、弧菌科弧菌、希瓦氏菌屬和聚球藻屬豐度高于對照組。

綜上所述，在淡水養(yǎng)殖條件下，飼料中添加0.18%–0.28%膽固醇與0.04%發(fā)酵膽汁酸可通過協(xié)同效應顯著提升凡納濱對蝦的生長性能、肝胰腺和腸道健康及腸道菌群狀況。本研究通過優(yōu)化FBAs與CHO配比，為提高淡水環(huán)境下凡納濱對蝦養(yǎng)殖效率提供了新方案，同時為降低飼料膽固醇含量、節(jié)約養(yǎng)殖成本提供了潛在策略。

Abstract

Cholesterol (CHO) is an expensive essential nutrient for crustaceans. Bile acids (BAs), which function as emulsi?ers facilitating lipid absorption in vertebrates, play a crucial role in the growth and sterol metabolism. This study conducted a 2-month feeding

experiment and aimed to investigate both the individual and interactive effects of dietary CHO and fermented BAs (FBAs; a novel type of FBAs) on growth performance, immune response, and intestinal health in Litopenaeus vannamei in freshwater environ- ment. A total of 12 isonitrogenous and isolipidic diets were formulated. These diets were formulated based on a basal diet by separately adding FBAs at a level of 0.04% (A3), CHO at levels of 0.05% (C1), 0.10% (C2), 0.20% (C3), 0.30% (C4), and 0.40% (C5) as well as combinations of FBAs and CHO at levels of A3C1, A3C2, A3C3, A3C4, and A3C5. A control group (N) without the addition of either FBAs or CHO was also included. Considering that the basic diet contained 0.08% CHO (from ?sh meal and other ingredients) and no detectable FBAs, the actual levels of CHO were adjusted to 0.08% (N), 0.13% (C1), 0.18% (C2), 0.28% (C3), 0.38% (C4), and 0.48% (C5). After 60 days, both FBAs, CHO, and their combination could improve the growth performance of shrimp, as indicated by ?nal weight (FW), weight gain (WG), and speci?c growth rate (SGR). The best promoting effect was found in A3C2 and A3C3 groups. Two-way analysis of variance (ANOVA) analysis revealed signi?cant synergistic effects between FBAs and CHO (p <0:05). These results suggest that CHO is more ef?cient than FBAs in promoting growth, but its ef?ciency can be signi?cantly enhanced when combined with FBAs. Hemolymph biochemical parameters, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), α-amylase (α-AMS), triglycerides (TGs), and acid phosphatase, were signi?cant affected by different treatments (p <0:05). Gene expression levels in the hepatopancreas showed signi?cantly lower levels of anti- lipopolysaccharride factor (ALF), prophenoloxidase (proPO), and alpha-2-macroglobulin (α2M) and signi?cantly higher levels of alkaline phosphatase (AKP) in different treated groups compared to the control groups (p <0:05). The addition of FBAs, CHO, and their combination to the diet increased gut microbiota diversity in L. vannamei. At the phylum level, there was a signi?cant decrease in Proteobacteria abundance and a signi?cant increase in Firmicutes, Tenericutes, and Cyanobacteria compared to the control group. At the genus level, Pseudoalteromonadaceae Vibrio, Vibrionaceae vibrio, Shewanella, and Synechococcus were found to be more abundant in the FBAs and CHO treatment group compared to the control group. In conclusion, a combination of 0.18%–0.28% CHO and 0.04% FBAs into feed formulations demonstrated synergistic effects on L. vannamei under freshwater conditions, signi?cantly enhancing their growth performance, hepatopancreatic and intestinal health, and gut microbiota. This study provides a novel approach for improving the ef?ciency of L. vannamei breeding in freshwater environments by optimizing the ratio of FBAs and CHO. Furthermore, it provides a potential strategy to reduce dietary CHO content, thereby lowering feeding costs.

翻譯：宋紫菱(黃海水產研究所營養(yǎng)飼料團隊)

轉載自：胖鲀先生；胖鲀文獻速覽：9月第四周(英文文獻-B篇)

原文：Guo Q, Pei S, Zhao L, et al. Synergistic Effects of Fermented Bile Acids and Cholesterol on Growth Performance, Immune Response, and Intestinal Microbiota of Litopenaeus vannamei in Freshwater Environment[J]. Aquaculture Research, 2025, 2025(1): 5959199.

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