Sundell Kristina, Berge Gerd Marit, Ruyter Bente, Sundh Henrik
Swedish Mariculture Research Center, Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
Norwegian Institute of Food, Fisheries and Aquaculture Research (Nofima), Nofima, Sjølsengen, Sunndalsøra, Norway.
Front Physiol. 2022 Apr 28;13:883621. doi: 10.3389/fphys.2022.883621. eCollection 2022.
Due to a limited access to marine raw materials from capture fisheries, Atlantic salmon feeds are currently based on mainly plant ingredients (75%) while only 25% come from traditional marine ingredients including marine fish meal and fish oil. Thus, current feeds contain less of the essential omega-3 fatty acids. The aim of the study was to assess the impact of different omega-3 levels in fish feed on intestinal barrier and transporting functions of Atlantic salmon freshwater and seawater smolts. Atlantic salmon were fed three levels of omega-3 (2, 1 and 0.5%) and fish performance was followed through smoltification and the subsequent seawater acclimation. Intestinal barrier and transporting functions were assessed using Ussing chamber methodology and combined with transcript analysis of tight junction related proteins and ion transporters. A linear decrease in growth was observed with decreasing omega-3 levels. Low (0.5%) inclusion of omega-3 impaired the barrier function of the proximal intestine compared to 2% inclusion. Further, low levels of omega-3 decrease the transepithelial electrical potential across the epithelium indicating disturbed ion transport. It can be concluded that low dietary levels of omega-3 impair somatic growth and intestinal function of Atlantic salmon.
由于从捕捞渔业获取海洋原材料的途径有限，目前大西洋鲑鱼饲料主要基于植物成分（75%），而只有25%来自传统海洋成分，包括海洋鱼粉和鱼油。因此，当前的饲料中必需的ω-3脂肪酸含量较低。本研究的目的是评估鱼饲料中不同ω-3水平对大西洋鲑鱼淡水和海水稚鱼肠道屏障及转运功能的影响。给大西洋鲑鱼投喂三种ω-3水平（2%、1%和0.5%）的饲料，并在稚鱼期及随后的海水驯化过程中跟踪鱼的生长性能。使用尤斯灌流小室方法评估肠道屏障和转运功能，并结合紧密连接相关蛋白和离子转运体的转录分析。随着ω-3水平降低，观察到生长呈线性下降。与添加2%的ω-3相比，添加低水平（0.5%）的ω-3会损害屏障功能。此外，低水平的ω-3会降低上皮细胞跨上皮的电势，表明离子转运受到干扰。可以得出结论，低水平的饲料ω-3会损害大西洋鲑鱼的体生长和肠道功能。
