Mango extractum additive promoting fish growth

Abstract: To improve the preventable level of aquatic disease, and keep the high level of safety of aquatic products, we explored the growing characteristics of tilapia, carp, and tortoise administrated with mango extractum, which was extracted from the leaves of mango with alcohol. The level of flavone was determined at the level of 32.34 % in the mango extractum. In this study, we have analyzed the livability, growth, feed ratio, nutrition, blood, and immunity of tilapia, carp, and tortoise, which is important to find a new feed nutritional additive with natural lower toxicity. Our results proved that tilapia, carp, and tortoise could all grow more quickly when was fed with mango extractum. The survival rate, body length, and body gain of tilapia increased from 80.13% to 86.61%, 70.36 mm to 73.23 mm, and 530.75 g to 576.47 g respectively, when the tilapia was administrated with 0.8‰ mango extractum. The relative weight gain of carp was enhanced from 114.94% to 147.87%, and the value was generally higher when the mango extractum dose in the feed was increased, although it was found to be dose-independent. The feed coefficients of carp and tortoise reduced from 2.04 to 1.79, and from 1.14 to 0.90, respectively. However, the nutritional composition in edible tissues of carp and tortoise kept at normal level including protein, fat, ash, and water content. At the same time, we found similar results of the viscerosomatic, hepatosomatic and somatotype indexes of tortoise fed with mango extractum. Moreover, we found that mango extractum lowers the level of blood sugar, cholesterol, and glyceride in tilapia and tortoise. The concentrations of cholesterol and triglyceride in the serum of carp decreased from 3.13 mmol/L to 2.46 mmol/L, and from 2.91 mmol/L to 2.42 mmol/L, respectively. The efficiency was improved along with the supplement of mango extractum. Our data also proved that mango extractum strengthened the activity of peroxidase, alkaline phosphatase, and lysozyme in the serum of tilapia. The concentrations of cholesterol and triglyceride in the serum of tortoise reduced from 8.17 mmol/L to 7.07 mmol/L, and from 2.35 mmol/L to 1.42 mmol/L, respectively, when the feedstuff was fortified with 0.8‰ mango extractum. The level of lipid peroxide, MDA in the serum of tortoise was weakened from 7.75 to 7.25 mmol/mL, when tortoise was fed with 0.8‰ mango extractum. From the above data, we found that the immunity of tilapia, carp, and tortoise was strengthened, and regulated by mango extractum.