The present study was conducted to investigate the probiotic role of the unicellular fungi, Aspergillus niger on growth performance, immunity, haematology and digestive enzymes in common carp, Cyprinus carpio. One non-supplemented group (T₀) was considered as control and two groups fed the fungi including T₁ (fish supplemented with diet containing 1 × 10³ A. niger) and T₂ (fish supplemented with diet containing 1 × 10⁶ A. niger) considered as the experimental treatments in three replicates. Fish were fed experimental diets for 60 days. The survival rate and growth parameters (final length and weight, weight gain (%), thermal growth coefficient (TGC), protein efficiency ratio and lipid efficiency ratio) significantly increased in A. niger supplemented fish compared with control (p < 0.05). The values of FCR (feed conversion ratio) and CF (condition of factor) significantly decreased after feeding experiment in fish of T₂ and T₁ compared with control (p < 0.05). The plasma levels of lysozyme and total immunoglobulin significantly elevated in A. niger supplemented groups compared with control (p < 0.05). The RBC (red blood cell) counts, Hb (haemoglobin) concentrations, MCH (mean corpuscular haemoglobin) and MCV (mean corpuscular volume) values significantly increased in A. niger supplemented fish compared with control (p < 0.05). The WBC (white blood cell) and Hct (haematocrit) value were higher in fish of T₂ compared with control (p < 0.05). The number of neutrophils significantly increased in the treatment, T₂ compared with control (p < 0.05). Furthermore, the lymphocyte counts significantly increased in A. niger supplemented fish compared with control (p < 0.05). The body composition of fish showed increases in the fish dry matter and protein content and decreases in lipid content of T₁ and T₂ groups compared with control (p < 0.05). The digestive enzymes (protease, trypsin, amylase, lipase and alkaline phosphatase), apparent protein ad lipid digestibility significantly increased in response to dietary level of 1 × 10⁶ A. niger compared with control (p < 0.05). The supplementation of fish with A. niger also prompted the load of the fungi in intestine (p < 0.05). The results of the present study confirmed the probiotic role of A. niger in common carp, since it improved growth, immunity, digestion and the fish haematology.

中文翻译：

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真菌黑曲霉对鲤鱼鲤鱼的生长、免疫、血液学、肠道真菌负荷和消化酶的益生菌作用

本研究旨在研究单细胞真菌黑曲霉对鲤鱼鲤鱼的生长性能、免疫、血液学和消化酶的益生作用。一个未补充组（T ₀）被认为是对照组，两组喂食真菌，包括T ₁（鱼补充含有 1×10 ³ A. niger的饲料）和T ₂（鱼补充含有 1×10 ⁶ A的饲料） . 尼日尔) 被认为是三个重复的实验处理。给鱼喂食实验饲料 60 天。与对照相比，添加黑曲霉的鱼的存活率和生长参数（最终长度和体重、增重（%）、热生长系数（TGC）、蛋白质效率比和脂质效率比）显着增加（ p  < 0.05）。与对照相比， T ₂和T ₁的鱼在投喂试验后FCR（饲料转化率）和CF（因素条件）值显着降低（ p  < 0.05）。黑曲霉的血浆溶菌酶和总免疫球蛋白水平显着升高补充组与对照组相比 ( p  < 0.05)。与对照相比，添加黑曲霉的鱼的 RBC（红细胞）计数、Hb（血红蛋白）浓度、MCH（平均红细胞血红蛋白）和 MCV（平均红细胞体积）值显着增加（ p  < 0.05）。与对照相比， T ₂鱼的 WBC（白细胞）和 Hct（红细胞比容）值较高（ p  < 0.05）。治疗组中性粒细胞数量明显增加，T ₂与对照组相比（p  < 0.05）。此外，黑曲霉的淋巴细胞计数显着增加与对照相比，补充鱼 ( p  < 0.05)。鱼体成分与对照组相比， T ₁和T ₂组鱼体干物质和蛋白质含量增加，脂质含量降低（ p  < 0.05）。消化酶（蛋白酶、胰蛋白酶、淀粉酶、脂肪酶和碱性磷酸酶）、表观蛋白质和脂类消化率在 1 × 10 ⁶ A. niger的日粮水平下与对照相比显着增加（p  < 0.05）。用黑曲霉补充鱼也促进了肠道中真菌的负荷（p < 0.05)。本研究的结果证实了黑曲霉在鲤鱼中的益生菌作用，因为它改善了生长、免疫、消化和鱼类血液学。