Prawn is in put seedling 30 days or so suddenly come on!Why?These three key points should be made clear
Prawn aquaculture is widely distributed in our country, the seedling time is also very different, in addition to the factory, jiangsu sheds to raise shrimp about miao is put in March, shandong, tianjin, liaoning and other places may put the miao, xinjiang region about the time in July, miao, and regions such as guangdong, guangxi, hainan, fujian can realize year-round breeding, put plants at any time.However, no matter when put seedlings, more or less there will be some problems, these problems are put seedlings should pay attention to the place, but also we should pay attention to the key control points in the process of breeding.The term “liver transition” is commonly used in prawn culture. It usually refers to the period when prawn is transformed from feeding natural bait to artificial compound feed.A sign of success is the visible white membrane at the back of the liver, which is essentially made up of fat and exists throughout the breeding cycle.It also marks the successful transformation of prawn feeding habits and the perfection of body digestion and absorption.The “transliver stage” is about 20 days after seedling release. With the change of water temperature, the phenomenon of entering the “transliver stage” may be advanced or delayed.Because this period of prawn is very sensitive to changes in the external environment, their own resistance is weak, is the most easy to disease period, a large part of aquaculture prawn is in this stage of the problem.Therefore, it is very important for breeding to successfully pass the “transliver period”.Key control point 2 Hepatoenterocytosis “My shrimps died while being raised from the beginning of seedling, and the dead shrimps were all bigger shrimps” and “my shrimps did not grow very long, even more than 100 shrimps were raised for three months”, which were mostly caused by the infection of hepatoenterocytosis.At present, there is no good treatment for shrimp infected with hepatoenterospora.Because it is parasitic in shrimp hepatopancreas cells, killing the worm is equal to killing shrimp.Slow onset and long incubation period are also a major difficulty in treatment.For hepatoenterospora, the first thought is not to kill, but to think more about how to ensure the integrity of hepatoenterospora, improve the physique of shrimp, control the number of worms.Because carry liver-enteric cyticoworm come on not necessarily, follow prawn constitution, and liver-enteric cyticoworm infection quantity circumstance has direct relation.The prevention and control of hepatoenteric cytiworm must bear in mind that the best window period for prevention and control of hepatoenteric cytiworm is within 30 days after the release of seedlings.At this time, shrimp organs are not mature, weak physique, poor resistance, the most susceptible to liver and intestinal cytiworm infection.Insecticide-repellent products such as Eucalyptus oil should be taken internally regularly.As above, shrimp infected with liverenterospora should be thoroughly cleaned and disinfected with quicklime, mulching pond should be thoroughly disinfected with mulching film pond, and factory farming can use caustic soda daub pond wall.In a word, thoroughly disinfect the water to prevent spores from multiplying.Internal administration should pay more attention to the control of the number of liver enterospora in the body, so that prawn does not cause disease, but also can raise out of prawn.Critical control point Vibrio trivio is definitely the number one killer in shrimp culture, especially the phenomenon of “acute hepatopancreas necrosis” about 30 days after seedling release, which is mostly caused by vibrio infection.On the one hand, the change of diet will cause discomfort and stress in the gastrointestinal tract, hepatopancreas and other digestive systems of prawn, resulting in low immunity.On the other hand, the water quality is not stable, prawn has not much impact on the feed table, but once the feed and began to feed, temperature change water change once appeared, is a fatal blow.For the prevention and control of vibrio, water colony detection should be done first. TCBS can be used to detect the number of water colony, but there is no absolute safety value standard (for reference only: ≤1000 vibrio/mL in water;Vibrio vibrio ≤100 / mL, preferably no).The potential infection risk can be judged according to the change of colony color and number. The more the number, especially the more vibrio chlorovibrio, the greater the infection risk.In addition, strengthening internal administration is still an important measure to deal with vibrio in vivo while well regulating bacteria and algae.It is important to understand that all exogenous prevention and control measures (disinfection, bottom modification, ecological suppression, etc.) aim to reduce the number or proportion of vibrio bacteria in the gut.Don’t think that if you succeed in the seedling test and put it down, everything will be all right. The real test is still to come.Do a good job after putting seedlings 30 days of seedling protection work, so that breeding to a higher level.