Abstract：
In the current study, the effects of dietary fulvic acid supplementation at levels of 0.5, 1 and 2% were examined in white-leg shrimp, Litopenaeus vannamei. A significant increase in the weight of the shrimp was observed in the group treated with 2% fulvic acid in comparison to the control group. This may have been associated with an increased digestive efficiency, with the food conversion ratio reducing from 2.4 to 1.9, and increased hepatopancreatic amylase, protease, and lipase enzyme activities. Enhanced activity of hemolymph superoxide dismutase was suggestive of an enhanced immune capacity, while hemolymph cell count increased by 16.4 and 13.6% in shrimp receiving diets supplemented with 1 and 2% fulvic acid, respectively. Additionally, the number of large granular cells increased by 37.3% and 40.8% relative to the control in these two groups. Furthermore, the lysozyme activity increased in shrimp receiving dietary supplementation of 1% and 2% fulvic acid by 16.7% and 24.7%, respectively. Phenol oxidase activity, which activates phagocytosis and encapsulation of invading pathogens, increased in all groups supplemented with fulvic acid, with the highest activity in the 1% fulvic acid group. Overall the present results suggest that fulvic acid is a promising feed additive for white-leg shrimp super-intensive culture.
摘要：
在目前的研究中,在白腿虾中检查了日粮中添加0.5％，1％和2％的富里酸的效果，凡纳滨对虾.与对照组相比,在用2%富里酸处理的组中观察到虾重量的显著增加。这可能与提高消化效率有关，随着食物转化率从2.4降低到1.9，肝胰腺淀粉酶增加，蛋白酶，和脂肪酶酶活性。血淋巴超氧化物歧化酶活性增强提示免疫能力增强，在接受补充1％和2％富里酸的日粮的虾中，血淋巴细胞计数增加了16.4％和13.6％，分别。此外,在这两组中，大颗粒细胞的数量相对于对照组分别增加了37.3%和40.8%。此外，在接受1%和2%富里酸膳食补充剂的虾中，溶菌酶活性分别增加了16.7%和24.7%，分别。酚氧化酶活性,激活入侵病原体的吞噬作用和包封，在补充富里酸的所有组中增加，在1%富里酸组中活性最高。总体而言，目前的结果表明，富里酸是一种有前途的饲料添加剂，用于白腿虾超密集培养。
