Aging shrimp pond transformation breeding technology

In Fangchenggang City, South American white shrimp farming has been on the rise in recent years. However, after years of aging shrimp ponds, the accumulation of organic matter such as manure and residual feed has caused the extreme eutrophication of the pond bottom, a large number of pathogenic organisms, and traditional breeding habits. After using lime and bleaching powder, the bottom of the pond is severely calcified, the buffering capacity of the bottom of the pond to the aquaculture pond water is reduced, and the self-purification capacity of the aquaculture pond water is reduced. After the calcification, the bottom of the pond tends to make the pond water relatively lack of phosphate and soluble silicate, which makes it difficult to release fertilizer at the initial stage and the water quality is very unstable. Now, combining the problems encountered in production, we will summarize the following aquaculture technology measures. We hope to benefit the promotion and guidance of shrimp aquaculture production in the future.

First, preparatory work
1. Improve shrimp pond aging ponds The most effective way to increase the yield and raise the breeding success rate is to improve shrimp pond conditions. The specific approach is: configure aerators; separate the water inlet and outlet, increase the number of sewage disposal facilities in the middle; increase the height of the slope of the pond to increase the water depth.

2. The clear pond in Qingtang aging pond is particularly important. The specific approach is: immediately after the shrimp is harvested, drain the pool water, clear the dirt in the pond, seal the gate and expose the bottom of the selenium pond, until the bottom of the pond cracks. Most of the silt is removed by hand or mechanically. Then spray the surface of the subsoil and the surface of the pool with a high concentration of disinfectants in the bottom of the pool, use a cattle or tractor to plow the bottom of the pond and smash the subsoil, and then expose the subsoil, and then manually or mechanically compact the subsoil.

3, fertilizer and water aging ponds in the fertilizer and water is very easy to grow moss, so we must pay special attention. There are many methods of fertilizer, the following is one: about 1Od before the release of seedlings, nanofiltration of seawater is about 1m, with quaternary ammonium salt complexed iodine disinfection drugs 1.Omg/L-1.5mg/L throughout the pool, 2d-3d after the morning with photosynthetic bacteria 10mg/L-15mg/L Quanquan sprinkle (ageing pond pond is often more eutrophic, disinfection should not be fertilized after), and thereafter, immediately turn the pool with aeration machinery, so that Pool water becomes cloudy. Two days later, if the water color has not yet been cultivated, topdressing with seawater auxin can be used, and some phosphates or soluble silicates can also be used as appropriate. Generally, 1.5kg urea+lkg superphosphate is applied per shrimp pond.

Second, shrimp selection and seedling density:
1. The selection of shrimp seedlings by shrimp seedlings has weaker effects on the sudden changes in temperature and salinity and the ability to avoid enemy invasion. The stocking of healthy and disease-free shrimps is the key to successful breeding. The main criteria for selection are as follows: 1 large quantity of good quality, neat specifications, full length of shrimp should reach 0.8-1.2em; 2 good vigor; rapid response, strong ability to reverse water; 3 consistent body color, gastrointestinal The food is full, the body surface is clean, and there are no attachments; 4 the body is complete, no damage, and the tentacles are able to move forward together, the tail fan is fully open, and the abdominal segment is longer.

2, shrimp seedlings put seedlings to adapt to changes in temperature and salinity is very poor, a short time the temperature exceeds 10 °C or salinity change more than 5 ‰, shrimp will appear significant discomfort or even death, so when the seedlings must be Do a good job in the transition of temperature and salinity and other physical and chemical factors. The time for seedlings should be early morning or afternoon in sunny weather. The location of the seedlings should be in the upwind direction of the pond. Put the seedling plastic bag in the pool water for 20 minutes before putting the seedlings, so that the internal and external water temperature balance and then open the bag mouth, the shrimp will be slowly released into the pool. Before putting the seedlings, the best water test is to take a small amount of shrimp seedlings and put them in a bucket filled with pool water. After 24 hours, the survival rate of the shrimp seedlings is observed, and the survival rate is above 95% before the seedlings can be released.

3, put the seedling density according to their own conditions in shrimp ponds to determine the density of seedlings, not blindly put. The principle is that the density of seedlings in aging ponds should not be less, and the general requirement is to put 20,000 to 30,000 tails per mu, which makes the cultivation difficult and relatively easy to manage.

Third, the usual water quality management
1. Regular use of beneficial microorganisms The beneficial microorganisms break down excess organic matter and convert it into nutrients that are conducive to the growth of algae. The organic matter can be benignly decomposed to avoid harmful substances such as ammonia nitrogen and other shrimp bodies. Microbial decomposition of nutrients produced by organic matter promotes the growth of algae, enriches natural bait in ponds, inhibits the increase of pathogenic microorganisms, and increases the immunity of shrimp. Commonly used beneficial microorganisms such as photosynthetic bacteria, probiotics and so on. Usually used once every lOd-15d, generally used on a sunny morning.

2, scientific and reasonable regulation of water culture early shrimp culture individual small, good water quality, stable water temperature, the pool of basic food rich, generally do not add a lot of pool water, depending on the water consumption, inhibit the gradual addition of methods, try to maintain a stable water level. In the medium term (before the arrival of the seedlings from 1 month to before the high temperature period), according to the measurement of water quality, generally 20% of the water is exchanged between 10 days and 14 days, which can increase the amount of dissolved oxygen in the pool, which is conducive to the normal growth of shrimp. In the middle and later stages of breeding, due to the increase of the feed amount of the matched bait, the excrement and residual bait of the shrimp increase, and the water can be changed about once every 7 days, each time changing the water by 80cm-lOOcm; the intermediate water drainage and the outlet gate drainage should be carried out at the same time when changing the water. . Once sudden changes in water quality occur, shrimp floating heads, etc., should be replaced by continuous changes of water and the use of photosynthetic bacteria, live bacteria and other biological activity improvement agents to improve water quality and keep the water fresh. Keep the water level above 1.9m throughout the breeding period.

3, the use of aerators per 0.25hm2 with two sets of waterwheel + a sinking tube + a jet flow. In this way, the water can be continuously and continuously oxygenated and aerated so that the water quality is always in the best condition. Under normal circumstances, within 30 days after planting, start the waterwheel type aerator twice a day, respectively, and turn it on and off at dawn and before noon for 2h~3h; after 30d~50d, the boot time can be extended as needed; after 80d breeding, Due to the increased pollution of the water itself, the total quality of the shrimp increased and it needed to be turned on throughout the day; the immersed tube type and jet type could be started all day long. In addition, in the absence of wind, fog, cloudy, rainy days should increase the number of boot time, so that the dissolved oxygen in the water is always maintained at 5mg / L or more.

4. Periodically detect environmental factors in the pool. When detecting environmental factors, if a certain factor is found to change greatly in the short term, special attention must be paid. It may be that the ecology in the pond is being destroyed. It is necessary to find out the reasons. And timely implementation of water quality protection agents and other measures. Under normal circumstances, the best control range of environmental factors in aging ponds is shown in the table.

Fourth, feed selection and ridicule
1. The quality of feedstuffs for feed selection is related to the growth rate, survival rate, disease resistance and water quality of shrimp. Therefore, high-quality, high-nutrient and stable brands should be selected.

2. Feeding Feeding Determining a reasonable amount of feed is one of the key technologies for aquaculture. Poor feeding affects growth, survival and disease resistance. Overfeeding increases costs, pollutes sediments and water quality, and causes illness. Therefore, the bait rate and feeding amount should be determined and adjusted according to the size of the shrimp, water temperature, water quality and weather conditions. If water quality is good before the seedlings are released, live food in the water is abundant, and if the seedlings are released for 4 h-lOh or longer, they may not be fed. Restocking density should be early feeding, and vice versa. After 5d-l1d, they can be fed with juvenile shrimp and bait. The bait rate is generally 10%-7%, and is cast (2-3 times a day). Raise the midterm (ie, body length 3cm ~ lOcm) bait rate of 3% -5%, cast 4 times a day. The amount of feeding in the evening accounts for 50% to 60% of the daily feeding amount. The amount of feeding should be based on the conditions of the feeding table. The feed control in the feed table is suitable for shrimps after 1 h-1.5 h, and the feeding of material feeds accounts for about 3% of the feeding amount on the day. At the same time, regular high-stability vitamin C, E, immune polysaccharides, allicin, seaweed powder, etc. can be added to the food in order to enhance the disease resistance of the shrimp. Abnormal weather, poor water quality, etc. should reduce the number and quantity of bait.

Fifth, scientific use of drugs Under normal circumstances, ponds should try not to use drugs. Daily disinfection can be done through a reservoir to prevent damage to the pond culture water environment. In the prevention and treatment of diseases, we must also identify the cause of the disease and use drugs correctly. When selecting drugs, it is necessary to strictly follow the relevant regulations for pollution-free aquatic products, use “three-effects” (high-efficiency, quick-effect, long-lasting), “three small” (small toxicity, small side effects, and small dosage) drugs. Accurately calculate the dose and apply it reasonably. Prevent misuse of fishery drugs, blindly increase the amount of medication or increase the number of medications, and extend medication time.

The bearing structure, fixed film systems and installation of this greenhouse is relatively simple. And due to it, raw material and manufacturing costs are affordable. Except the  high strength woven film is higher, other kinds of antidrop film are economical. In general, the comprehensive cost of film greenhouse is lower 30% ~ 50% than the same size and specifications of the other types of greenhouse.