The common diseases of P. vannamei from June to July are red body disease (torah disease), white spot disease, bacterial red-leg disease, and black shank disease. The emphasis in farming is on strengthening water quality management and disease prevention. It is currently in a hot season, the weather is unpredictable, and the frequency of thunderstorms and sultry days is still relatively high. Mutations in the water environment make it easy for the shrimp to produce an emergency response and lead to morbidity. In order to ensure the healthy culture of P. vannamei, it is necessary to focus on the difficulties and achieve high and high yields. First, pay attention to weather changes, do a good job of oxygenation and water change. In the summer, due to the high water temperature, shrimp grows fast, feeds a lot, excreta is much, water quality is easily deteriorated, and it easily causes oxygen deficiency. Should insist on daily hours of early morning and noon oxygenation for several hours. Due to the changing weather, we must listen to the weather forecast every day and make good precautions against thunderstorms and winds. We should promptly add water, turn on oxygen, or throw out particulate oxygen to prevent signs of hypoxia. Before and after the thunderstorm, the aerator was oxygenated for several hours. Where conditions permit, it is necessary to change the water quality in a timely manner, change the water in a timely and appropriate manner, change the water in a small number of ways, avoid large-scale irrigation, and properly increase the water level, try to maintain at 1.5 meters or more, so that the lower and middle temperature can still Keep within 32°C. Second, regulate and control the water quality, improve the quality of white shrimp growth is in the middle and late, due to large feed amount, the pool of residual bait and excrement, the increase in the water pollution in the bottom layer, the timely application of beneficial microbial agents to regulate water quality, improve the substrate . Microbial preparations and sediment modifiers are generally administered every 15-20 days. At present, according to screening and clinical trials in recent years, the commonly used biological agents are EM original dew, green micro-kang, fish and shrimp auxin (CBS), live water treasure (Bacillus), imidazole, nitrification treasure (pure nitrifying bacteria ), etc., commonly used bottom modifier is zeolite powder, excellent net or (1 + 1) bottom net, particulate oxygen, etc., shrimp farmers can use their own production and water quality conditions to choose to use. The focus of the next phase of management is to improve the water quality in the middle and lower layers and to improve the pool bottom environment, prevent the occurrence of hypoxia, ammonia nitrogen, and nitrite at the bottom and cause nitrite poisoning. Third, feed high-quality materials, control the amount of feed Penaeus vannamei feed should be fed fresh and high-quality South American white shrimp full-rate feed, and in the feed regularly added suitable tolerance, vitamin C, immune polysaccharides, etc., to enhance the shrimp Immunity and anti-stress ability. In summer, shrimps have large food intake, rapid digestion, and increased daily feeding rates. They should adopt a small amount of multi-meal feeding methods, feeding 2-3 times a day, 70%-80% in the morning and evening, 20%-30% in the daytime, try to avoid High temperature time. Daily feeding should be based on the weather, water quality, shrimp health and activity. The general principle is to check the bait station without leaving residual baits as a guideline. After eating within 1-1.5 hours of feeding, it is better to eat within 1 to 1.5 hours of feeding. When the weather is hot or thunderstorms occur, little or no feeding is possible. This can reduce the feed coefficient and reduce the body of water. Pollution pressure. Fourth, pay attention to disease, water quality testing The entire South American white shrimp breeding process should adhere to the "prevention, health management" principle. In addition to grasping inspection and quarantine of shrimp seedlings, disinfection of clear ponds, and disinfection of regular water bodies, we should pay attention to disease and water quality testing, and test the disease once every 25-30 days in the universities or research institutes with testing conditions. Disease-free prevention, disease early treatment early control. Once a disease or detected shrimp has been detected as carrying a virus or germ, control measures should be promptly taken. We must also pay attention to the detection of important water quality indicators such as dissolved oxygen, ammonia nitrogen, and nitrite, and find that one of the indicators exceeds the standards and timely adopts water quality control measures. Fifth, the round of catching and cultivating, catching big and keeping small in summer Due to the rapid growth of South American white prawns, they are generally well-bred. As long as they have been kept for 60-70 days, there will be a large amount of shrimps up to the commodity specifications in early July. The technical measures for dredging and catching up and keeping small will be timely listed on shrimps that meet the specifications, so as to maintain a reasonable shrimp density in the pond, promote the growth of shrimp, and reach the market specifications as soon as possible. The trapping method is recommended to be trapped in the ground cage and to use as little net as possible to avoid catching the shrimp and causing emergency response. According to weather forecast of the meteorological department, a severe typhoon will affect southern China from late August to early September. Therefore, the leaders, technicians, and shrimp farmers of the fisheries departments in the South should be highly valued and vigilant. They should be carefully managed and actively guide the shrimp farmers to catch rare fish in order to strive to obtain the majority of shrimps of commercial specifications before the end of August. So as not to suffer losses. 6. Insist on duty management to prevent unexpected accidents. In addition to checking whether various facilities are in good condition, we will focus on observing the changes in water quality of shrimp ponds and the activities of shrimps, checking the protection of power supply and water supply facilities, observing the appearance of diseased shrimp, and the phenomenon of hypoxia floating heads. Necessary production accidents and economic losses.
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