A 56‐day feeding trial was conducted to investigate the effects of arachidonic acid (ARA) supplementation on growth and immunity of plant protein‐fed turbot (Scophthalmus maximus L.). Five isonitrogenous and isoenergetic diets were formulated, including fishmeal group (0.6 g/kg ARA), plant protein group (0.2 g/kg ARA) and plant protein groups supplemented with ARA (2.6, 7.4 and 11.8 g/kg ARA). Results showed that replacement of dietary fishmeal by plant protein blend significantly inhibited weight gain rate (WGR) from 511.53 ± 2.92% to 399.32 ± 5.40%. The specific growth rate (SGR) and final body weight (FBW) were also reduced. However, supplying ARA up to 11.8 g/kg could restore the WGR, SGR and FBW to the similar levels with FM group (p > .05). In addition to decreasing nutrient digestibility and distal intestinal morphology, the plant protein‐based diet also attenuated innate immune enzyme activity and triggered intestinal inflammation, which were significantly improved by ARA supplementation. Dietary ARA restored the expression of the anti‐inflammatory cytokine (transforming growth factor‐β) and reduced pro‐inflammatory cytokine (tumour necrosis factor‐α, interleukin‐1β and interleukin‐8) mRNA levels. Taken together, ARA supplementation in the plant protein‐based diet could improve growth performance and alleviate intestinal inflammation caused by dietary plant protein in juvenile turbot.

中文翻译：

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膳食花生四烯酸补充剂可改善幼年大菱t的生长性能，并减轻基于植物蛋白的饮食引起的炎症（Scophthalmus maximus L.）。

进行了为期56天的喂养试验，以研究花生四烯酸（ARA）对植物蛋白喂养的大菱t（Scophthalmus maximus L.）生长和免疫力的影响。制定了五种等氮和等能日粮，包括鱼粉组（0.6 g / kg ARA），植物蛋白组（0.2 g / kg ARA）和补充了ARA的植物蛋白组（2.6、7.4和11.8 g / kg ARA）。结果表明，用植物蛋白混合物替代膳食鱼粉可将增重率（WGR）从511.53±2.92％抑制至399.32±5.40％。比生长率（SGR）和最终体重（FBW）也降低了。但是，提供最高11.8 g / kg的ARA可以使WG组的WGR，SGR和FBW恢复到与FM组相似的水平（p > .05）。除了减少营养物质的消化率和远端肠道形态外，以植物蛋白为基础的饮食还减弱了先天免疫酶的活性并引发了肠道炎症，而ARA的添加可以显着改善肠道内炎症。饮食ARA可恢复抗炎细胞因子（转化生长因子β）的表达，并降低促炎细胞因子（肿瘤坏死因子α，白细胞介素1β和白细胞介素8）的mRNA水平。综上所述，在以植物蛋白为基础的饮食中补充ARA可以改善生长性能并减轻幼年大菱diet中饮食性植物蛋白引起的肠道炎症。