Mehrabi Zibandeh, Firouzbakhsh Farid, Rahimi-Mianji Ghodrat, Paknejad Hamed
Department of Fisheries, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.
Department of Fisheries, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.
Fish Shellfish Immunol. 2020 Sep;104:74-82. doi: 10.1016/j.fsi.2020.05.050. Epub 2020 May 21.
In this study, effects of nettle (Urtica dioica) on growth, immunity, and gene expressions were examined in rainbow trout after an 8-week feeding period. A total of 264 juvenile rainbow trout (10.72 ± 0.55 g) were selected and stocked randomly in 12 aquaria. Nettle powder was added to the fish feed at three doses, 0.5,1 and 1.5% served as treatments. At the end of 8-week feeding period, the fish were exposed to Saprolegnia parasitica for 3 weeks. Results showed that all treatments fed with nettle diets exhibited significant increases in weight gain and SGR, and decreased FCR compared to the control. Feeding the fish with dietary nettle resulted in significant rises in blood indices and non-specific immunity in comparison with the control. Furthermore, fish fed 0.5% of dietary nettle showed significantly increased expressions of TNF-α, IL-1b, IL-6 and IL-8 genes following 8 weeks of feeding. A significant reduction in mortality rate was observed in the fish treated with 0.5% of nettle compared to the control following challenging with S. parasitica. Our observations indicate that the use of 0.5% nettle powder in rainbow trout diet can improve growth and immunity parameters as well as fish resistance against S. parasitica contamination.
在本研究中，在8周的投喂期后，检测了荨麻（Urtica dioica）对虹鳟生长、免疫力和基因表达的影响。总共挑选了264尾虹鳟幼鱼（10.72 ± 0.55克），随机放养在12个水族箱中。将荨麻粉以0.5%、1%和1.5%三种剂量添加到鱼饲料中作为处理组。在8周投喂期结束时，让鱼接触寄生水霉3周。结果表明，与对照组相比，所有投喂荨麻饲料的处理组鱼的体重增加和特定生长率均显著提高，饲料系数降低。与对照组相比，用荨麻饲料喂养鱼导致血液指标和非特异性免疫力显著提高。此外，在投喂8周后，投喂0.5%荨麻饲料的鱼的肿瘤坏死因子-α、白细胞介素-1β、白细胞介素-6和白细胞介素-8基因表达显著增加。在用0.5%荨麻处理的鱼中，与对照组相比，在受到寄生水霉攻击后观察到死亡率显著降低。我们的观察结果表明，在虹鳟饲料中使用0.5%的荨麻粉可以改善生长和免疫参数以及鱼对寄生水霉污染的抵抗力。
