Laboratory of Aquatic Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang, PR China.
Key Laboratory of Aquatic, Livestock and Poultry Feed Science and Technology in South China, Ministry of Agriculture, Zhanjiang, PR China; Aquatic Animals Precision Nutrition and High Efficiency Feed Engineering Research Center of Guangdong Province, Zhanjiang, PR China; Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, PR China.
Fish Shellfish Immunol. 2022 Dec;131:137-149. doi: 10.1016/j.fsi.2022.10.005. Epub 2022 Oct 4.
The study evaluated the effects of dietary phosphorus supplementation on the fishmeal replacement with Clostridium autoethanogenum protein (CAP) in the diet of L. vannamei. Four isonitrogenous and isolipid diets were formulated: the PC diet contains 25% fishmeal, the NC, P1 and P2 diets were replaced 40% fishmeal with CAP and supplemented with 0, 0.8 and 1.6% NaHPO respectively (equivalent to dietary phosphorus level of 0.96%, 1.12% and 1.27%). Sampling and V. parahaemolyticus challenge test were conducted after 50-day-feeding (initial shrimp weight 1.79 ± 0.02 g). The results showed that there were no significant differences in the growth performance of shrimp among the 4 groups. The expressions of dorsal in the gut were significantly lower in shrimp fed the P1 and P2 diets than shrimp fed the NC diet and the expression of peroxinectin in the gut was lower in shrimp fed the NC diet than others. The cumulative mortality of shrimp after V. parahaemolyticus challenge was significantly lower in shrimp fed the P2 diet than those fed the NC diet. After the challenge, genes expressions related to the prophenoloxidase activating system (proPO, lgbp, ppaf) were inhibited in the hepatopancreas of shrimp fed NC diet but activated in shrimp fed the P1 diet compared to those fed the PC diet. The AKP and T-AOC activities were higher in shrimp fed the P2 diet than those fed the other diets. The thickness of muscle layer of shrimp fed the P1 diet was thicker than that in the other groups, and significant stress damage happened in the midgut of the shrimp fed the NC diet. The abundance of Pseudoalteromonas, Haloferula and Ruegeria in shrimp fed the P1 diet was higher than those fed the other diets, while Vibrio in shrimp fed the P2 diet was higher than those fed the other diets. This indicated that a low fishmeal diet with dietary phosphorus level of 1.12% could improve the histology, enhance immune response, and increase the abundance of beneficial bacteria in the gut of shrimp. The low fishmeal diet with dietary phosphorus level of 1.27% could improve disease resistance and antioxidant capacity, but there was a possibility of damage to the gut histology as well as increasing abundance of Vibrio in the gut microbiota of shrimp.
本研究评估了在南美白对虾饲料中用产丁酸梭菌蛋白（CAP）替代部分鱼粉并补充不同磷水平对饲料磷的影响。配制了 4 种等氮等脂的饲料：PC 组饲料含 25%鱼粉，NC、P1 和 P2 组饲料分别用 CAP 替代 40%鱼粉并额外添加 0、0.8 和 1.6%的 NaHPO4（相当于饲料磷水平 0.96%、1.12%和 1.27%）。摄食 50 天后采样并进行副溶血弧菌攻毒试验（初始虾体重 1.79±0.02g）。结果表明，4 组虾的生长性能无显著差异。与 NC 组相比，P1 和 P2 组虾肠道背角蛋白表达显著降低，NC 组虾肠道过氧化物酶原激活物（peroxinectin）表达显著低于其他组。副溶血弧菌攻毒后，P2 组虾累计死亡率显著低于 NC 组。攻毒后，NC 组虾肝胰腺中与酚氧化酶原激活系统（proPO、lgbp、ppaf）相关的基因表达受到抑制，而 P1 组虾的这些基因表达则被激活。与 PC 组相比，P2 组虾的 AKP 和 T-AOC 活性更高。与其他组相比，P1 组虾的肌肉层厚度更厚，NC 组虾的中肠出现明显的应激损伤。P1 组虾的假交替单胞菌、盐单胞菌和海栖热袍菌丰度高于其他组，而 P2 组虾的弧菌丰度高于其他组。这表明，低鱼粉饲料（磷水平 1.12%）可改善虾的组织学结构，增强免疫反应，增加肠道有益菌的丰度。低鱼粉饲料（磷水平 1.27%）可提高虾的抗病力和抗氧化能力，但可能会损伤虾的肠道组织学结构，并增加肠道菌群中弧菌的丰度。
