Prevention of Disease Caused by EHP Spores on Shrimp

EHP according to the General Department of Fisheries, the\r\nsituation of EHP bacterial spores infection in brackish water shrimp is on the\r\nrise. This is a disease that does not cause mass death but has a huge\r\neconomic impact on shrimp farming because when the shrimp get sick, it will\r\ngrow slowly, even not large even though it still consumes a lot of food (farmed\r\nshrimp). 90-100 days of age can still reach the size of 4-5 grams / individual\r\n(200-250 heads / kg).

Shrimp infected with EHP showed no typical signs such as\r\nwhite spot disease or acute hepatopancreatic necrosis but mostly slow growth,\r\nsoft shell and pale hepatopancreas. There is currently no specific\r\nsolution for this disease. Therefore, to prevent the spread of disease\r\ncaused by EHP, shrimp farmers are recommended to apply some general preventive\r\nmeasures as follows:

Seed : Need\r\nto choose good seed tested without carrying common pathogens in\r\nshrimp. Select shrimp seed from reputable companies and production farms.

Moderate stocking density: For black tiger shrimp 15-25\r\nshrimp / m 2 , for Pacific white shrimp 60-70 shrimp / m 2 .

Settling ponds : In\r\nintensive and semi-intensive culture, it is required to have settling ponds\r\nwith an area equal to at least 30% of the pond area in order to be able to\r\nactively supply fresh water to the pond at any time. For settling ponds,\r\nit also needs to be renovated and must be disinfected thoroughly before\r\nsupplying water into ponds.

Pond improvement : It\r\nis necessary to follow the pond renovation procedure to eliminate pathogens\r\nthat existed from the previous crop.

For lined lined ponds, it must be scrubbed, sun dried,\r\ntreated with lime to remove germs, wash, chlorine treated at least 30 ppm, and\r\ndisinfect water thoroughly before coloring.

For soil ponds, plowing and drying should be done at least\r\n2-3 weeks. Treat with lime, then wash ponds, treat with chlorine at least\r\n30 ppm, disinfect thoroughly before watering and coloring. Ponds need to\r\nbe treated and tested for vibrio density in water and in soil\r\nthoroughly before coloring.

Biosecurity: Absolutely\r\ncomply with biosecurity in ponds to avoid the spread of pathogens between ponds\r\non the same farm. Items used for shrimp care or inspection should be sited\r\nseparately to help prevent spread between one pond and another. Farms with\r\nponds contaminated with EHP should pay special attention to spreading by water\r\nor by caregivers.

Health management: Regularly\r\nchecking food sieves to avoid overfeeding affecting water quality and\r\nfacilitating the supply of nutrients to groups of pathogens. Regularly\r\ncheck the color of hepatopancreas, appearance (color, hard condition of shrimp\r\nshells), distribution of size, etc.

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Managing water\r\nquality: Regularly monitoring the basic elements in the pond such as\r\npH, temperature, alkalinity, dissolved oxygen to timely adjust, avoiding shrimp\r\nshock caused by the environment will create conditions for pathogens work and\r\ncause disease outbreaks.

Source : tepbac.com