Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand.
Discipline of Excellence Sustainable Aquaculture, Faculty of Science and Industrial Technology, Prince of Songkla University, Surat Thani Campus, Surat Thani 84100, Thailand.
Fish Shellfish Immunol. 2019 Oct;93:1067-1075. doi: 10.1016/j.fsi.2019.07.084. Epub 2019 Aug 3.
Fishmeal is the main source of protein in the shrimp feed industry and is normally derived from trash fish. As such, the production of fishmeal has an adverse effect on the marine environment by taking away small and juvenile fish, leading to depletion of marine species. There is a need for alternative sources of protein which will substitute fishmeal in the aquaculture industry. This study evaluated the components and nutritional efficacy of bioflocs, which were used to substitute fishmeal protein. The effect of bioflocs diets on growth performance, survival rate, and immune response in shrimp compared to normal fishmeal feed were determined. Bioflocs were harvested from the shrimp ponds (C:N ratio >12:1) at Shrimp Village, Chaiya district, Surat Thani, Thailand. The total protein in bioflocs was about 48% and the total lipid was about 5% (dried weight) and the percentages of essential amino acids (EAA) and fatty acids (EFA) in bioflocs were similar to those of fishmeal feed. Shrimp fed with the different dietary bioflocs feed regimens [% to replace fishmeal; 0% (B0), 25% (B25), 50% (B50), 75% (B75), and 100% (B100)] for 42 days revealed that all growth parameters were almost similar to those of the control shrimp (shrimp fed with normal fishmeal, B0) including final body weight, weight gain, specific growth rate, and feed conversion ratio. Remarkably, the survival rates, the levels of immune parameters, and expression of immune genes (proPO-I, PEN-4 and dicer) were significantly higher in bioflocs fed shrimp, especially in B25 and B50 shrimp. Moreover, B25 and B50 bioflocs fed shrimp showed notably increased survival rates following Vibrio parahaemolyticus (V. parahaemolyticus) infection. In conclusion, the present study demonstrates that shrimp survival and immunity are enhanced by biofiocs substituted fishmeal. Significantly, the bioflocs diets activated the immune response to prevent V. parahaemolyticus infection.
鱼粉是虾饲料工业中蛋白质的主要来源，通常来自于杂鱼。因此，鱼粉的生产通过带走小鱼和幼鱼对海洋环境产生了不利影响，导致海洋物种枯竭。需要寻找替代蛋白质来源，以替代水产养殖中的鱼粉。本研究评估了生物絮团的成分和营养价值，该生物絮团被用于替代鱼粉蛋白。与正常鱼粉饲料相比，生物絮团饲料对虾的生长性能、成活率和免疫反应的影响。生物絮团是从泰国春武里府柴亚区虾村的虾塘（C:N 比>12:1）中收获的。生物絮团的总蛋白含量约为 48%，总脂肪含量约为 5%（干重），生物絮团中的必需氨基酸（EAA）和必需脂肪酸（EFA）的百分比与鱼粉饲料相似。虾在不同的饮食生物絮团喂养方案下（替代鱼粉的百分比；0%（B0）、25%（B25）、50%（B50）、75%（B75）和 100%（B100））喂养 42 天后，发现所有的生长参数几乎都与对照组虾（用正常鱼粉喂养的虾，B0）相似，包括最终体重、体重增加、特定生长率和饲料转化率。值得注意的是，在生物絮团喂养的虾中，存活率、免疫参数水平和免疫基因（proPO-I、PEN-4 和 dicer）的表达显著高于对照组虾，尤其是在 B25 和 B50 组。此外，在感染副溶血弧菌（V. parahaemolyticus）后，B25 和 B50 生物絮团喂养的虾的存活率显著提高。总之，本研究表明，用生物絮团替代鱼粉可以提高虾的成活率和免疫力。显著的是，生物絮团饮食激活了免疫反应，以防止副溶血弧菌感染。
