Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Zagazig University, 44511, Zagazig, Sharkia, Egypt.
Kuwait Institute for Scientific Research, KISR, Kuwait.
Fish Shellfish Immunol. 2018 Sep;80:281-290. doi: 10.1016/j.fsi.2018.06.016. Epub 2018 Jun 9.
The present study investigated the effects of dietary supplementation of yeast nucleotides on the hematology, antioxidant activity, non-specific immunity, expression of intestinal cytokines, and disease resistance in Nile Tilapia (Oreochromis niloticus). Fish weighing 42.90 ± 0.14 g were randomly divided into four groups. Each group was set in triplicate (15 fish per replicate). Fish were fed on four dietary levels of yeast nucleotides (NTs) supplemented with the basal diet 0% (control), 0.05%, 0.15%, and 0.25% NTs. Significantly higher total serum protein, albumin, total serum globulin, total WBC counts, and lymphocyte and granulocyte contents were recorded in 0.25% NT group as compared to the control. The albumin/globulin ratio (A:G) showed a considerable decrease in the 0.25% NT group. The non-specific immune parameters; serum killing percentage, lysozyme activity, nitric oxide assay, IgM levels, and anti-protease activity, were significantly higher in the 0.25% NT group as compared to the control. Moreover, a 15-day feeding trial demonstrated improved results in terms of serum lysozyme activity, nitric oxide assay, IgM levels, and anti-protease activity than a 30-day feeding trial. A significant increase in the anti-oxidant status of O. niloticus was noticed, as reflected by increased superoxide dismutase and malondialdehyde activity in the serum of 0.25% NT group compared to the control, while glutathione peroxidase displayed a significant increase in all groups as compared to the control. The intestinal cytokines TGF-β, IL-1β, IL-10β, and TNF-α mRNA levels showed a pattern of 0.25% NT > 0.15% NT > 0.05% NT > 0% NT, as relative to the control Ef-1α levels. The relative survival percentages of fish fed on yeast nucleotide-supplemented diets, as analyzed by exposure to Aeromonas sobria, were significantly better than the control group. In conclusion, dietary yeast nucleotide administration at 0.25% improved blood proteins, leukocytes, antioxidant activity, non-specific immunity, cytokine gene expression, and disease resistance of Nile Tilapia.
本研究旨在探讨酵母核苷酸对尼罗罗非鱼（Oreochromis niloticus）血液学、抗氧化活性、非特异性免疫、肠道细胞因子表达和抗病能力的影响。将体重为 42.90±0.14g 的鱼随机分为四组，每组设三个重复（每个重复 15 条鱼）。各组投喂四种不同酵母核苷酸（NTs）水平的日粮：基础日粮中不添加（对照组）、0.05%、0.15%和 0.25% NTs。与对照组相比，0.25% NT 组的总血清蛋白、白蛋白、总血清球蛋白、总白细胞计数以及淋巴细胞和粒细胞含量显著升高。0.25% NT 组白蛋白/球蛋白比值（A:G）明显降低。非特异性免疫参数，如血清杀菌百分比、溶菌酶活性、一氧化氮测定、IgM 水平和抗蛋白酶活性，在 0.25% NT 组均显著高于对照组。此外，15 天的喂养试验结果显示，血清溶菌酶活性、一氧化氮测定、IgM 水平和抗蛋白酶活性的改善效果优于 30 天的喂养试验。与对照组相比，0.25% NT 组超氧化物歧化酶和丙二醛活性显著升高，尼罗罗非鱼的抗氧化状态明显增强，而谷胱甘肽过氧化物酶在所有组中的活性均显著高于对照组。肠道细胞因子 TGF-β、IL-1β、IL-10β和 TNF-αmRNA 水平相对于对照组呈现出 0.25% NT>0.15% NT>0.05% NT>0% NT 的模式，而 Ef-1α 水平则呈现出相反的模式。与对照组相比，投喂酵母核苷酸补充日粮的鱼的相对存活率经分析后显著提高。综上所述，日粮中添加 0.25%的酵母核苷酸可提高尼罗罗非鱼的血液蛋白、白细胞、抗氧化活性、非特异性免疫、细胞因子基因表达和抗病能力。
