The key to shrimp culture is to think correctly and clearly. Only in this way can we control the situation of shrimp culture and improve it in the right direction.
Shrimp culture is a systematic project.
The knowledge of shrimp culture involves many aspects, from seeding to feed management, from pond cleaning to fertilizer and water transfer, from season to salinity to pH, from water quality and environment to nutritional balance to improving immunity, etc. Only by mastering these aspects can the risk of shrimp culture be minimized. It is unrealistic to think that you can win by mastering one or two special drugs or one or two special additives or one or two special technologies.
In the systematic project of shrimp culture, all the factors in each link are independent and can't replace each other, but they are interrelated with each other. In this system engineering, it is generally believed that seedling, material and management are the most important three aspects. Seedling is high-quality shrimp seedling, feed is high-quality feed, and management is high-quality. Shrimp seedlings and feed are relatively intuitive and easy. You can get what you want for a penny, as long as you are willing to pay a high price, but quality management is more complicated.
High-quality management means that all the work that should be done should be done well. Management is a concept that can be big or small. In a broad sense, all the work of shrimp farming is management, and it is implemented through management. Management in a narrow sense refers to the management of a certain stage, a certain link and a certain aspect of shrimp culture. The management of shrimp culture is complicated and involves many things, but the most important thing is how to keep enough dissolved oxygen. Dissolved oxygen is the center of shrimp culture, and it determines the success or failure of shrimp culture.
The key to shrimp culture is dissolved oxygen.
Dissolved oxygen is not only the center of shrimp culture, but also the guarantee of water quality and environment. Now it is generally 1-2 mu 1 set. It is far from enough to meet the required dissolved oxygen by this number of aerators, and it is obviously unrealistic to equip it with reference to the mode of nursery, and it is of no economic significance to invest heavily.
At present, we use the combination of fertilizer water and aerator to obtain dissolved oxygen. The so-called fertilizer water is to cultivate algae through fertilization and obtain dissolved oxygen through photosynthesis of algae. This is the main source of dissolved oxygen, accounting for more than 70%, and the aerator can only play a supplementary role.
In the process of shrimp culture, sediment, water quality, water color and Ph value. Ammonia nitrogen, nitrite, hydrogen sulfide, heavy metals, etc. are all joint reflections of algae growth. The reason why we spend a lot of manpower, material resources and financial resources to pay attention to and deal with these factors is to ensure that algae growth is kept in a good state, enough dissolved oxygen has been obtained, and the water environment is stable. Establishing this idea means grasping the key points, and other problems will be solved easily.
As the dissolved oxygen needed for high-density shrimp culture, it should not only be sufficient, but also stable, avoid ups and downs, and not be confused by the temporary standard and beauty. Shrimp can't be raised well when dissolved oxygen fluctuates greatly. Too thin water indicates that the number of algae is small, indicating that there is less dissolved oxygen, and shrimp is easy to get sick. Too much water indicates that algae are aging and dying in large numbers, that dissolved oxygen is sharply reduced, and that the original benign balance of algae, bacteria and toxins is destroyed. At this time, shrimp is more likely to get sick under extreme stress.
Red water, yellow water, blue water and other harmful algae are dominant, and shrimp are also prone to get sick. Algae itself is also metabolized every day, and it is also changing and changing. The above shows that it is indeed difficult to maintain good algae in a good state in the process of shrimp culture, which requires us to master the basic knowledge of fertilizer, water transfer and water conservation, learn the skills of observing water color every day, and master the comprehensive analysis of daily water quality indicators, so as to achieve a well-targeted goal.
Raising shrimp = raising water = raising algae. The essence of dissolved oxygen problem is algae problem, and all harmful substances such as ammonia nitrogen, nitrite, hydrogen sulfide and heavy metals are also produced because of insufficient dissolved oxygen, so the key to shrimp culture is to raise algae well. Management of algae must be careful and diligent. Because the water environment of high-density shrimp culture is not natural but man-made, the ecological balance formed by this man-made water environment is temporary, conditional and very fragile. It must be managed every day to maintain it, and any carelessness will be bad.
Grasp the advantages and disadvantages, seek advantages and avoid disadvantages
All measures to raise shrimp have advantages and disadvantages, and the advantages and disadvantages exist. It is necessary to comprehensively analyze and grasp the advantages and avoid disadvantages. The breeding process is a contradictory and balanced project. On the one hand, the organic matter is increasing, the water quality is acidifying and the hardness of the water body is decreasing. On the other hand, the success of shrimp culture is ensured by taking continuous measures to degrade the organic matter, prevent acidification, improve the hardness of the water body and form a new balance.
1, exchange local losses for the stability of the big environment. For example, it is easy to lack phosphorus in the middle and late stage of shrimp culture, and phosphorus becomes a limiting factor for the growth of shrimp and algae, so it is necessary to supplement phosphorus frequently. This time is also the rainy season, and lime and zeolite powder should be sprinkled frequently to stabilize the pH value and improve the hardness of the water body. However, lime and phosphorus are contradictory. Generally speaking, phosphorus should be used only after the interval of 10- 15 days after lime is used, so that the effect is good. If the interval is too short, phosphorus precipitation will fail, but if phosphorus is not supplemented in time, the problem will be even greater, so phosphorus can only be supplemented frequently, even if precipitation is wasted.
Disinfectants and microecological agents are also contradictory. If all the fungi, including beneficial bacteria and harmful bacteria, are killed by putting enough disinfectant, it will inevitably make the water body sterile for a period of time. As a high-density shrimp culture, aseptic state is not a good thing. Aseptic state means that the benign material circulation system in the original water body is destroyed, resulting in a large accumulation of toxic substances, which will affect the growth of algae, and shrimp will easily have problems during this period of time. Therefore, only a small amount of chlorine-containing disinfectants can be put in for many times, so that some beneficial bacteria can continue to play their roles, and the water body can be disinfected and oxidized, reducing anaerobic harmful bacteria, promoting the reproduction and growth of aerobic beneficial bacteria, and further improving the whole water environment.
Practice has proved that it is not worth the loss to kill harmful algae with copper sulfate and other drugs in the process of shrimp culture. Although harmful algae are killed, shrimp soon has problems. After using copper sulfate, almost all shrimps have problems for about half a month, and there are few successes.
2. Grasp the quantity and degree of implementation. Any measure must be well measured and measured, otherwise it will be counterproductive. Sprinkling lime, fertilizing, topdressing, using disinfectants, using microecological agents, and even using aerators all have a real-time and moderate problem. For example, sprinkling hydrated lime in a small amount for many times has many advantages, one is to improve the hardness of water body, which is reasonable for algae reproduction, the other is to supplement calcium to shrimp to promote its growth, and the third is to complex toxic substances.
The same is true of chlorine-containing disinfectants. A small amount of chlorine-containing disinfectants can effectively inhibit the excessive growth of algae, obviously alleviate the color of excessive water, quickly degrade toxic substances and effectively improve the bottom material. The effect is good and economical. However, if the amount of one-time use is too large, it will bring a series of side effects, and even the harm caused by side effects is far greater than the original problem.
No matter what drugs are used, in addition to reading the instructions carefully, we should also combine the actual situation of our own shrimp pond, which must be carried out on the basis of understanding the principle and comprehensive analysis. Often, many times the problem was not serious, but it was aggravated because of the eagerness to change.
3, the operation should be fine. Every measure has stress. The operation is learned. If you slowly approach in the operation and give the shrimp an adaptation process, the stress will be reduced. For example, adding water is the same, and the effect is good if the amount is small and it is carried out slowly for many times, and the effect is poor if it is too urgent and too fast, or even counterproductive.
Prevention of shrimp disease lies in the early stage of culture
The biggest risk of shrimp culture is shrimp disease, which occurs in the early stage of shrimp culture, that is, within 30 days after seedling casting. Therefore, the management in the early stage of shrimp culture is the key to the success of shrimp culture. Prevention of shrimp disease should be based on prevention, based on early, and should start from clearing the pond.
It is wrong to think that shrimp with good bottom quality and rich natural bait will not be deprived of oxygen in the early stage of seedling casting. If you think that it will take 20 days after seedling casting to enter the risk period, it will be easy to have problems, and then you will start to pay attention to it seriously, it will be too late.
The occurrence of shrimp disease is not the causal relationship between yesterday's rain and today's disease, but the shrimp was sub-healthy before it rained, and there was a problem. Rain was just the fuse and catalyst.
In the past, we also paid attention to the prevention of shrimp diseases, but we didn't get the idea. We just treated the symptoms from the head to the foot, lacking foresight and initiative in preventing shrimp diseases. The level of shrimp culture can only be successful if it stays in good weather, and the weather is a little abnormal. Prevention of shrimp diseases lies in the early stage of culture. It is necessary to clarify how many main pathogenic factors exist in the early stage of breeding, and then take sexual measures in advance to solve them one by one.
1, acid reflux prevention. When cleaning the pond, sprinkle lime and calcium magnesium phosphate as appropriate.
2. Remove crabs and shrimps, and reduce the source of infection. Fence with black plastic cloth, kill with trichlorfon or pyrethroid.
3. Degradation of heavy metals. Spraying disodium or organic acid 1 week before seeding.
4, prevent bubble disease. When the pH value is greater than 9.3, do not plant seedlings in the afternoon or evening, but only before 10 o'clock in the morning or change the date of planting.
5. Prevent caving. The aquaculture water level is kept at 1.2- 1.5m, and the water is too shallow to cave in.
6. Maintain sufficient dissolved oxygen. After seeding, the aerator should be turned on at night and at noon for 1-2h. If the water color is too strong, increase the intensity of oxygenation at night, and even sprinkle oxygen-increasing agent at the same time. There are plans to put in microecological agents and scrape the sediment as appropriate.
7. Algae. It is not advisable to use disinfectants that are too strong and too lethal to algae before the first fertilizer application. For the first time, organic fertilizer and inorganic fertilizer should be fully applied, and it should be carried out on sunny days. If serious harmful algae such as cyanobacteria (blue water), dinoflagellate (red water) and triceratops (yellow water) appear, those that have not been planted should be drained and re-watered. Those that have been planted do not advocate the use of algae-killing drugs such as copper sulfate, but advocate the use of microecological agents and comprehensive measures such as brown sugar, glucose and rice bran, and carry out repeated finishing.
8. Manage the algae. On the one hand, we should pay attention to topdressing, apply more frequently and less, promote algae reproduction and growth, and prevent algae from falling off. On the other hand, when the water color is too strong, a small amount of bleaching powder should be applied as appropriate to degrade the water color and prevent algae bloom. Ammonia nitrogen, hydrogen sulfide, nitrite, and so on are all derivatives of algae, which is the main source of shrimp disease. Prevention of algae bloom = prevention of shrimp disease.
9. Physical fitness is enhanced. Pay attention to the importance of early opening, pay attention to strengthening the physique of shrimp, and pay attention to the use of liver-protecting and anti-stress products. Bile acid can be used in the period of shrimp liver conversion to protect the liver and improve the immunity of shrimp. Strong liver will have strong disease resistance!
Prevention of shrimp disease depends on science and care. Prevention of shrimp disease depends not on 1-2 drugs or 1-2 measures, but on comprehensive preventive measures. All the work to be done belongs to the prevention of shrimp disease.