Here, we investigated the effects of total dietary fish oil (FO) substitution with plant oil (PO) on hematological indices, immune status, antioxidant activity, IL1β and TNF-α gene expression, and hypoxia stress resistance in Oreochromis niloticus at suboptimal temperatures. Fish (n = 360) were randomly divided into 12 circular fiberglass tanks (500 L; 3 replicates for each dietary group, 30 fish/replicate, 90 fish/group). The control group was fed a basal diet with FO as the lipid source. The CO, SFO, and LSO groups were fed a basal diet with complete replacement of FO with corn, sunflower, and linseed oils, respectively. After 4 weeks, no effects on hematological indices were observed in fish fed the experimental diets. The LSO and CO groups showed a significant increase in γ globulin levels. The highest levels of non-specific immune parameters, antioxidant activity, and IL-1β and TNF-α gene expressions were recorded in the LSO group. The LSO group also exhibited good resistance to hypoxia stress. Therefore, the total dietary substitution of FO with PO (especially LSO and CO) is recommended as a valuable strategy to ameliorate the immunosuppressive effects of suboptimal temperatures and enhance the resistance of O. niloticus to hypoxia stress.

中文翻译：

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用植物油代替膳食鱼油可改善暴露于最适温度下的尼罗罗非鱼的免疫反应和抗氧化状态。

在这里，我们研究了在亚适温下尼罗罗非鱼对全日粮鱼油（FO）替代植物油（PO）对血液指标，免疫状态，抗氧化活性，IL1β和TNF-α基因表达以及耐缺氧胁迫的影响。将鱼（n = 360）随机分成12个圆形玻璃纤维水箱（500升；每个饮食组3个重复，每个重复30个鱼，每个组90个）。对照组饲喂以FO为脂质源的基础饮食。给CO，SFO和LSO组喂食基础饮食，分别用玉米油，向日葵油和亚麻子油完全替代FO。4周后，在喂食实验饮食的鱼中未观察到对血液学指标的影响。LSO和CO组显示γ球蛋白水平显着增加。最高水平的非特异性免疫参数 LSO组记录了抗氧化活性以及IL-1β和TNF-α基因的表达。LSO组还表现出良好的抗缺氧应激能力。因此，建议在膳食中用PO完全替代FO（尤其是LSO和CO），作为改善次适温的免疫抑制作用并增强尼罗罗非鱼对低氧胁迫的抵抗力的有价值的策略。