5 Tips to Double Profit of Shrimp Farming
In recent years, China's shrimp industry has developed rapidly, but it has also suffered a lot of obstacles. Because it has seriously exceeded the environmental capacity, many problems are aggravated and new problems continue to appear. So, what are the five key points in shrimp culture? How to improve the success rate of shrimp culture?
1.Shrimp fry
Good shrimp fry is the key to the success of aquaculture, especially shrimp. When purchasing the fry, we should carefully screen and select the natural and energetic shrimp fry. We should not buy the unhealthy fry with virus and weak immunity by mistake because of some differences in price. For shrimp fries, don’t "lose the watermelon picked up sesame."
2.Culture density
Density not only affects the yield of prawn, but also affects the quality of prawn. Do not blindly pursue the yield and increase the density. Overload breeding will lead to the increase of ammonia nitrogen and nitrite content due to lack of oxygen in the late stage of breeding, which will reduce the immunity of prawn and cause diseases and even a large number of deaths. If the density of shrimp is too high, a part of adult shrimp should be sold in advance at the end of shrimp culture, which can relieve the pressure of water environment and improve the selling rate of surplus shrimp. For the culture density, the water quality of different regions is quite different, and the water quality of different geographical environments in the same region is also very different. We should choose the appropriate culture density according to the local and water conditions, and weigh the advantages and disadvantages.
3.Feed
The feed contains the essential amino acids, phospholipids, vitamins and the mineral elements needed for shrimp growth. It contains anti stress and immunity additives. At the same time, the feed cost is the largest input in the cultivation, accounting for about half of the cost of culture. Good feed not only meets the nutritional needs of prawn, but also has high utilization rate, suitable carbon-nitrogen ratio, and the least residual waste produced, and the minimum impact on water quality. In the actual feeding process, it should be flexible to adapt to the situation of weather and shrimp feeding activities.
4.Cultural Water
As long as the water quality is well treated, it is almost impossible that shrimp can not be raised. Many problems are caused by water, and many measures and methods also focus on how to regulate water quality. Water is the carrier of breeding organisms. The whole life activities of shrimp are carried out in the water body, including breathing and excretion of waste. Therefore, shrimp farming is water farming. The water quality is the most complex and controllable, and it is also the biggest link in the development and governance space.
(1) Breeding temperature
The culture temperature of prawn is relatively sensitive to temperature change, especially the influence of high temperature and low temperature. In the process of breeding, the temperature in the morning and evening, as well as the temperature in the sun and rain changed greatly, especially in the late summer and early autumn.
Temperature can affect the physiological function of shrimp, the activity of related enzymes and the normal secretion of molting hormone. When the temperature is low, its metabolism is low, and the energy required to maintain normal metabolism is increased, that is, the proportion of energy distribution in maintaining metabolism is increased, and the corresponding energy used for shrimp body growth and shrimp meat growth is reduced, which is not conducive to the sale of shrimp and the saving of feed cost.
If the temperature is lower or even lower than 9 ℃, shrimp will die. On the contrary, with the increase of temperature, the growth of prawn will be accelerated, but the increase of temperature also has two sides. Higher temperature will make the water quality change greatly, which is difficult to control, and the dissolved oxygen will be reduced. Moreover, microorganisms, especially harmful bacteria, will reproduce rapidly, which is difficult to manage. Therefore, the best temperature is controlled at 22 ~ 30 ℃, or it should be adjusted for a short time.
(2) Dissolved oxygen
Dissolved oxygen plays an important role in the culture of Penaeus vannamei. Shrimp can't live without water and oxygen. Higher dissolved oxygen can improve the survival rate. If the shrimp is exposed to anoxic environment for a long time, it will lead to the digestion and absorption of nutrients and a series of enzymatic reactions can not be carried out normally, and the body will be damaged, pathological changes will occur, and even lead to the phenomenon of "steal death" of shrimp. When the culture density is too high or the fertilization is too much, the transparency of the water body will be too low, and then the photosynthetic efficiency of algae will be reduced, and the microorganisms and algae at the bottom of the water body will compete for oxygen. In this case, if the oxygen supply of the aeration equipment is insufficient, the dissolved oxygen of the water body will be too low, and the shrimp will lack oxygen, leading to the occurrence of diseases. When the dissolved oxygen is too low, some anti stress drugs can be added, and the dissolved oxygen can be increased in time
(3) Ammonia nitrogen
The cause of ammonia nitrogen is mainly due to the decomposition and deamination of shrimp bait, animal and plant residues by microorganisms; the increase of water pH will also increase the content of ammonia nitrogen and increase its toxicity to shrimp. The production of ammonia nitrogen in water is closely related to its existence and dissolved oxygen. In addition, by changing water, adding biological agents, feeding a small amount of feed for many times and other methods to effectively reduce ammonia nitrogen.
(4) Algae
Algae is the foundation of shrimp culture. Algae can not only provide oxygen, but also purify water, but algal decay will also produce algal toxins. We should pay attention to the changes of algae every day, and often use detoxification drugs or em bacteria and other beneficial bacteria to prevent the adverse effects of algal toxins produced by algal decay on shrimp. In addition, water should be changed regularly, algae should be added in time, and stress drugs should be used to stabilize the shrimps.
5.Disease prevention and rational drug use
In recent years, the main reason for shrimp breeding diseases is that the breeding environment is not up to the standard, which is mainly manifested in the high levels of ammonia nitrogen, nitrite and sulfide in the aquaculture water, and the decline of algae, leading to the further deterioration of the aquaculture water environment; the direct reason is that the disease caused by shrimp infection is due to the proliferation of pathogenic bacteria such as Vibrio. It can lead to the chronic and acute death of shrimp. In view of this kind of phenomenon, we should quickly apply the corresponding antibacterial drugs and supplement EM bacteria, Bdellovibrio bacteriophagus and other beneficial bacteria. The treatment of diseases and water quality should be carried out at the same time.
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