Two trials were conducted as follows: the first trial was a 90-day experiment to determine the effects of reducing feeding level on shrimp status; the second trial (90 days) is based on the first trial to explore the suitable C/N ratio of biological flocs for shrimp culture in outdoor soil ponds. Results showed that the BFV levels increased gradually and then tended to be stable in the treatment groups. Concentrations of TAN and NO2-N were maintained low level in each treatment pond during experimental period. The final body weight, biology body length and yield of the shrimp in each trial with no significantly different (P > 0.05) while food coefficient and THC of the shrimp in 70% feeding level and C/N12 treatment were slightly lower than in the 100% feeding level and C/N16 treatment respectively (p < 0.05). The antibacterial activity and bacteriolytic activity in C/N16 treatment group were higher than in C/N12 (p < 0.05), while there were no significant difference between the two feeding levels (70%,100%) (P > 0.05). The shrimp in 70% feeding level and C/N12 treatment had the higher T-AOC in both the plasma and the hepatopancreas when compared with 100% feeding level and C/N16 treatment group (p < 0.05). The SOD activity of plasma in 70% treatment group was higher than in 100% (p < 0.05), while it was no significant difference between the two C/N ratios (12,16) in both the plasma and the hepatopancreas (P > 0.05). The effects of two feeding levels and C/N ratios on the GSH level and the ratio of GSH/GSSG in the plasma and the hepatopancreas of shrimp showed no significant difference (P > 0.05). The results showed that 70% feeding level and C/N12 ratio could provide adequate nutrition for shrimp to maintain a normal physical health status with the presence of bioflocs.

中文翻译：

---

零水交换生物絮凝物为基础的室外土壤培养池中饲喂水平和碳氮比对南美白对虾水质，生长性能，免疫和抗氧化状态的影响。

进行了以下两个试验：第一个试验是90天的试验，以确定降低摄食水平对虾状态的影响；第二次试验（90天）基于第一次试验，以探索适合在室外土壤池中进行虾类养殖的生物絮凝物的C / N比。结果显示，治疗组中BFV水平逐渐升高，然后趋于稳定。在实验期间，每个处理池中的TAN和NO2-N浓度保持在较低水平。在每个试验中，虾的最终体重，生物学体长和产量均无显着差异（P> 0.05），而在摄食水平为70％和C / N12处理时，虾的食物系数和THC略低于100。 ％饲喂水平和C / N16处理（p ＜0.05）。C / N16处理组的抗菌活性和溶菌活性均高于C / N12（p <0.05），而两种喂养水平之间无显着差异（70％，100％）（P> 0.05）。与100％饲喂水平和C / N16处理组相比，饲喂水平为70％和C / N12处理的虾血浆和肝胰腺中的T-AOC均较高（p <0.05）。70％治疗组的血浆SOD活性高于100％（p <0.05），而血浆和肝胰腺中的两个C / N比（12,16）之间无显着差异（P> 0.05）。两种饲喂水平和C / N比对虾血浆和肝胰脏中GSH水平和GSH / GSSG比例的影响无显着性差异（P> 0.05）。