A 12-wk trial was conducted to compare the tolerance of tilapia to high carbohydrate and high lipid diets. Three isonitrogenous and isoenergetic diets, whose carbohydrate and lipid levels were the following: 35.0% and 8% (control), 44.2% and 4% (D1, high carbohydrate), and 25.8% and 12% (D2, high lipid), respectively. Three hundred tilapias (27 ± 0.11 g) were fed the diets for 10 wk (4 replicates per group); 72 fish from the D1 group were continually fed the D1 (D1D1) and 72 fish from the D2 were continually fed the D2 (D2D2) diet for 2 wk (3 replicates each group) to evaluate the tilapia's capacity to tolerate high carbohydrate and high lipid diets, respectively. Another 36 fish from D1 group were continually fed D2 (D1D2) for comparison with D1D1 and D2D2 groups. In phase 1, hepatosomatic index, liver triglycerides (TG), glucose tolerance (GT) and crude protein in the whole body in D1 group were higher than those in D2 group (P < 0.05). During phase 2, D1D1 group had lower feed intake and weight gain, as well as lower serum total protein and albumin than that of D2D2 group (P < 0.05), while its liver glycogen was significantly higher than that in D1D2 and D2D2 groups (P < 0.05). Moreover, serum glucose and GT were higher in D1D1 and D1D2 groups than those in D2D2 group (P < 0.05). By contrast, D2D2 group had significantly higher intraperitoneal fat, subcutaneous adipose tissue (SCAT) and liver TG than those in D1D1 group (P < 0.05). The mRNA expression of brain npy, hepatic nrf2, gst1 and hepatic transcriptomic data showed that immune-related genes (gama, mrc2, mhc2 and cd163), were downregulated in D1D1 group compared to D2D2 and D1D2 groups. Taken together: 1) tilapia have higher tolerance to a high lipid diet than high carbohydrate diet; 2) despite retention of glucose tolerance, the continuous feeding of D1 diet impaired tilapia's appetite, weight gain rate and host immune response; 3) specific distribution of fat in intraperitoneal regions, SCAT and liver may be a risk-avoidance strategy in tilapia in response to a continuous D2 diet.

进行了一项为期 12 周的试验，以比较罗非鱼对高碳水化合物和高脂肪饮食的耐受性。三种等氮等能量饮食，其碳水化合物和脂质水平如下：分别为 35.0% 和 8%（对照）、44.2% 和 4%（D1，高碳水化合物）以及 25.8% 和 12%（D2，高脂质） . 将 300 条罗非鱼 (27 ± 0.11 g) 喂食 10 周（每组重复 4 次）；D1 组的 72 条鱼连续喂食 D1 (D1D1)，D2 组的 72 条鱼连续喂食 D2 (D2D2) 饲料 2 周（每组重复 3 次），以评估罗非鱼耐受高碳水化合物和高脂肪的能力饮食，分别。来自 D1 组的另外 36 条鱼被连续喂食 D2 (D1D2) 以与 D1D1 和 D2D2 组进行比较。在第 1 阶段，肝体指数、肝脏甘油三酯 (TG)、P  < 0.05）。D1D1 组 2 期采食量、增重、血清总蛋白和白蛋白均低于 D2D2 组（P  < 0.05），而肝糖原显着高于 D1D2 和 D2D2 组（P  < 0.05)。此外，D1D1 和 D1D2 组的血糖和 GT 高于 D2D2 组（P  < 0.05）。相比之下，D2D2 组腹腔内脂肪、皮下脂肪组织（SCAT）和肝脏 TG 显着高于 D1D1 组（P  < 0.05）。脑npy、肝nrf2、gst1的mRNA表达及肝转录组数据显示免疫相关基因（与 D2D2 和 D1D2 组相比，D1D1 组中的gama、mrc2、mhc2和cd163 ）被下调。综合来看：1）罗非鱼对高脂饮食的耐受性高于高碳水化合物饮食；2）尽管保持了糖耐量，但持续饲喂D1日粮会损害罗非鱼的食欲、增重率和宿主免疫反应；3) 脂肪在腹膜内区域、SCAT 和肝脏的特定分布可能是罗非鱼响应连续 D2 饮食的一种风险规避策略。