Apricot Algae Stimulates Immunity Against Phosphorescent Disease in Shrimp

Recent research has shown that apricot algae extract has the\r\nability to stimulate immunity and increase survival rate in black tiger shrimp\r\nto help shrimp against disease caused by Vibrio harveyi.

Black tiger shrimp ( Penaeus monodon ) is a\r\nspecies of high economic value and is raised in many countries around the\r\nworld. According to a report of the General Department of Fisheries, as of\r\nSeptember 24, 2019, brackish shrimp farming area reached 705,209 ha, of which\r\ntiger shrimp farming area is 606,661 ha. The harvested output is 504,413\r\ntons, of which, the production of black tiger shrimp is 181,585\r\ntons. However, in recent years, due to climate change, the process of\r\nsaline intrusion has led to many black tiger shrimp farming, poor quality seed,\r\nand frequent epidemics. Some common diseases in black tiger shrimp such as\r\nWSSV, yellowhead disease YHV, disease caused by micro-spores of EHP, acute\r\nhepatopancreatic necrosis caused by Vibrio parahaemolyticus ,\r\nphosphorescent disease caused by V. harveyi. Illuminating disease is\r\nfound in larvae, postlarvae of black tiger shrimp and damages economic and\r\nshrimp farming of many countries in the world.

When recognizing the signs of disease, most farmers use\r\nchemicals and antibiotics to treat the disease, unreasonable dosages lead to\r\nsome strains of resistant bacteria that reduce the effectiveness of use,\r\nresidues in the environment and Food affects consumers' health.

Supplementing herbal extracts is one of the measures\r\nresearched by many scientists due to its high biosecurity, both ability to\r\nprevent and treat diseases and less impact on the environment and consumers'\r\nhealth.

Currently, the demand for seaweed is very large, they serve\r\nas a source of food, fodder, fertilizer and medicinal source (SánchezMachado et\r\nal., 2004). In particular, brown seaweed has been identified as a rich\r\nsource of bioactive materials with many biological activities such as\r\nantioxidant, antibacterial, antifungal, anti-coagulant, anti-UV-B radiation,\r\ncapable of making heals wounds and regenerates cell structure, enhances\r\nimmunity (Liu et al., 2012). Specifically, fucoidan is a substance\r\nextracted from brown seaweed, containing polysaccharides sulfate, can help\r\nboost immunity for black tiger shrimp, whiteleg shrimp against white spot\r\ndisease virus (WSSV), or stem redness caused by micro bacterium V.\r\nalginolyticus.

Apricot algae is a species of seaweed, which grows into\r\nlarge dust, brownish yellow or olive brown, is a species of brown\r\nalgae. In traditional medicine, apricot algae is considered a valuable\r\nmedicine, widely applied in the fields of medicine, industry and\r\nfisheries. Research Tran Trung Giang, 2015 said that the mixture of\r\npolysaccharide extracted from brown algae S. microcystum has\r\nthe ability to stimulate growth, enhance immunity of white shrimp when\r\nsupplemented with a ratio of 1.0% to feed. . Simultaneously,\r\npolysaccharide extracted from brown algae S. microcystum was\r\nevaluated as a strong antioxidant (Huynh Truong Giang et al., 2013).

The trial was conducted to assess the effect of a mixture of\r\napricot algae extract ( Sargassum microcystum ) added to the feed for\r\nblack tiger shrimp ( Penaeus monodon ). Shrimp were fed with a\r\ndiet supplemented with S. microcystum extract of\r\nvarious algae extracts at different levels (0%, 0.5%, 1%, 2% from apricot\r\nextract), fed continuously. in 30 days.

A challenge test for Vibrio harveyi was conducted in a 60 L\r\nplastic bucket with 30 shrimp / treatment.

Result

The total number of white blood cells (THC), the number of\r\ngranulated white blood cells (LGC), the number of seedless white blood cells\r\n(HC) and the enzyme PO activity increased significantly in the 1% supplement\r\ngroup. from apricot algae, the highest survival rate (80%) was recorded in the\r\ndietary supplement group with a concentration of 1% of algae extract after\r\ninfection with V. harveyi. At the same time, the feeding of 1% of S.\r\nmicrocystum extract from apricot algae can increase the immune response and\r\nresistance to V. harveyi in black tiger shrimp.

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Illness disease caused by V. harveyi is a common disease\r\ncommon in both black tiger shrimp and black tiger shrimp. When infected shrimp\r\nwill stop eating and grow slowly, affecting the productivity of the\r\ncrop. Therefore, adding apricot extract to shrimp feed to limit disease is\r\nessential. New research has introduced a new method by adding only 1% of\r\napricot algae extract to shrimp feeds to stimulate immunity against pathogens.

Source : tepbac