Addicted astragalus polysaccharides to shrimp feed can improve the immunity of shrimp, effectively prevent and treat diseases such as white spot, red body, small hepatopancreas, jejunum, empty stomach, and strengthen the tolerance to insufficient oxygen and stimulance. When the weather changes and dissolved oxygen is lacking, it can prevent the stress response of the prawns, and can relieve the head floating of the prawns when the algae are turned into water.
In the test, in Crayfish injection of white spot syndrome virus can increase the survival rate by more than 20% after application of astragalus polysaccharides.
It can also improve the survival rate of carp and catfish infected with Aeromonas hydrophila.
Astragalus polysaccharides can prevent sea cucumber from vomiting, stomach rot, swollen mouth, rotten side and body stiffness. It is reported to promote the growth of sea cucumber, improve the digestion and absorption of sea cucumber to feed and the synthesis of collagen protein, enhance the tolerance of sea cucumber to high heat stratification and hypoxia at the bottom of rised temperature, and improve the anti-stress ability and survival rate of sea cucumber.
In aquaculture, the use of astragalus polysaccharides can partially replace antibiotics, and has the functions of enhancing immunity, improving disease resistance, promoting growth, and anti-oxidation. It is necessary to explore the appropriate amount of addition of each aquatic animal to get best performance
1. Astragalus polysaccharides enhance immune function.
The immune tissues and organs of fish include: spleen, thymus, kidney and lymphoid tissue, etc. Astragalus polysaccharides can significantly improve the quality of immune organs of carp, tilapia and crucian carp, and improve the immunity of fish.
It can stimulate macrophages and leukocytes, enhance their phagocytic activity, and increase the number and immunity of mast cells and lymphocytes.
2. Astragalus polysaccharides can improve intestinal function. Astragalus polysaccharides have inhibitory effects on Escherichia coli, Salmonella and Pseudomonas aeruginosa, and can also promote the growth of probiotics such as Bifidobacterium and Lactobacillus in the intestine of fish, reduce the bait coefficient, and improve the growth performance and survival rate of fish.
Astragalus polysaccharides can also thicken the intestinal mucosal wall, enlarge the intestinal absorption area, and improve the digestion and absorption rate of the intestinal tract. Astragalus polysaccharides can increase the length of intestinal villi, depth of crypts and thickness of muscle layer in tilapia, and increase the number of intestinal mucus cells and intraepithelial lymphocytes. It can increase the hepatotrypsin activity of prawns and the digestive enzyme activity of sea cucumber.
3. Polysaccharides in astragalus extract improves growth rate and aquatic product quality. It is suitable for a variety of aquatic animals such as eel, tilapia, prawn, crayfish, crucian carp, sea cucumber and so on.
4. Astragalus polysaccharides works as antioxidant. Under pathological and stressful conditions, fish will produce excess reactive oxygen species, attack cell membranes, proteins and DNA, causing tissue and cell damage and metabolic disorders in fish resulting poor growth and immunity and rising disease. Astragalus polysaccharides can increase superoxide dismutase in various fish, reduce the damage of free radicals to tissues, and improve the antioxidant function and immune function of fish.
