The dietary effect of lemon essential oil loaded in chitosan nanoparticles (LEO/CNPs) on growth performance, serum biochemical parameters, humoral immune responses, and body composition in rainbow trout was evaluated. Two hundred and forty juvenile fish (4.74 ± 0.14 g) were randomly distributed to four experimental groups with three replicates in 12 fiberglass tanks (140 L; 20 fish per tank). The fish were fed a basal diet (commercial pellet; 50.5% protein and 13.1% fat) supplemented with 0 (control), 0.5, 0.75, and 1% LEO/CNPs for 56 days. At the end of the trial, the highest final weight (32.04 ± 1.22 g), weight gain (27.40 ± 1.36 g), and specific growth rate (3.45 ±0.12% day⁻¹) were observed in 1% LEO/CPN treatment (P < 0.05). Besides, feed conversion rate significantly improved in 1% LEO/CNPs treatment (0.65 ± 0.01) compared to 0.5% LEO/CNPs (0.82 ± 0.07) and the control group (0.79 ± 0.03). Serum aspartate transaminase and alkaline phosphatase values were not affected by dietary LEO/CNPs (P > 0.05), while alanine aminotransferase level (13.21 ± 0.42 U L⁻¹) showed a significant decrease in 1 % LEO/CNPs treatment compared to 0.5% LEO/CNPs and the control group (P < 0.05). The serum cholesterol, triglycerides, and glucose were significantly reduced following the oral administration of 0.75 and 1% LEO/CNPs (P < 0.05). Lysozyme activity (32.26 ± 1.14 U mL⁻¹) and complement C3 (39.64 ± 4.76 mg dL⁻¹) significantly increased in the fish treated with 1% LEO/CNPs. The higher and lower contents of crude protein and lipid were obtained in 1% LEO/CNPs, respectively, than the control group. Overall, the synergistic interaction between LEO and CNPs in 1% LEO/CNPs treatment may be responsible for improving the growth performance and immuno-physiological responses of rainbow trout.

评估了负载在壳聚糖纳米颗粒 (LEO/CNPs) 中的柠檬精油对虹鳟鱼的生长性能、血清生化参数、体液免疫反应和身体成分的饮食影响。240 条幼鱼 (4.74 ± 0.14 g) 随机分配到四个实验组，在 12 个玻璃纤维罐（140 L；每罐 20 条鱼）中重复三次。给鱼喂食基础饲料（商业颗粒；50.5% 蛋白质和 13.1% 脂肪）并补充 0（对照）、0.5、0.75 和 1% LEO/CNP，持续 56 天。在试验结束时，在 1% LEO/CPN 治疗中观察到最高的最终体重（32.04 ± 1.22 g）、体重增加（27.40 ± 1.36 g）和比生长率（3.45 ±0.12% day ^-1）（磷< 0.05)。此外，与 0.5% LEO/CNPs (0.82 ± 0.07) 和对照组 (0.79 ± 0.03) 相比，1% LEO/CNPs 处理的饲料转化率 (0.65 ± 0.01) 显着提高。血清天冬氨酸转氨酶和碱性磷酸酶值不受饮食 LEO/CNPs 的影响 ( P > 0.05)，而丙氨酸转氨酶水平 (13.21 ± 0.42 UL ^-1 ) 显示与 0.5% LEO/CNPs 处理相比，1% LEO/CNPs 处理显着降低CNPs 和对照组（P < 0.05）。口服 0.75 和 1% LEO/CNPs 后血清胆固醇、甘油三酯和葡萄糖显着降低（P < 0.05）。溶菌酶活性 (32.26 ± 1.14 U mL ^-1 ) 和补体 C3 (39.64 ± 4.76 mg dL ^-1) 在用 1% LEO/CNPs 处理的鱼中显着增加。与对照组相比，1% LEO/CNPs 中粗蛋白和脂质的含量分别较高和较低。总体而言，在 1% LEO/CNPs 处理中 LEO 和 CNPs 之间的协同相互作用可能是改善虹鳟鱼生长性能和免疫生理反应的原因。