CATDOLL : CATDOLL: Why do white shrimp produce white feces and how to prevent and control it?

1. Why do white shrimp produce white feces and how to prevent and control it?

The industry generally believes that the factors that cause "white stool" include feed nutritional quality (mycotoxins in moldy feed), drug abuse (antibiotics), pathogenic microorganisms (Vibrio), algae toxins, etc., as well as bad weather, deteriorating water quality, and poor bottom water environment.

Targeted measures taken in the early and middle stages of white stool can have a certain therapeutic effect. When the disease develops to the later stage, the shrimp has obviously reduced the feed or stopped eating, and it will be very difficult to treat it. Therefore, the prevention and control recommendations for white stool are based on the principle of "prevention before disease, early treatment when diseased, prevention as the main, and prevention and control combined". Targeted comprehensive measures should be taken according to the actual situation from the aspects of improving the physical fitness of shrimp, optimizing the water environment, and cutting off the transmission pathways of pathogens. In daily management, choose good quality feed, feed reasonably, regularly feed shrimp with products such as Changgan Ning, Dingding Qiang, and Beibei Jia, and do a good job of pond inspection. When intestinal abnormalities are found, the cause of the disease should be diagnosed in time, and Jingan Licholeretic + Changchanghao AB + Beibei Jia should be mixed to regulate the liver and intestines, and Dingding Qiang should be sprayed externally. According to the actual situation of the water body, relevant measures should be taken to improve the water environment, and pay attention to eliminating the cause of the disease.

2. Tips for raising South American shrimp How to raise South American shrimp

1. Pond structure. Most ponds are 10-20 mu in size, long and “U” shaped, with the deepest water level up to 2 meters, and the middle part is flat and often less than 1 meter. The soil is viscous and contains a certain salinity. The water source is mostly river water, with a salinity of less than 0.2%, a hardness of more than 200, and low pollution. The average water level is 60cm in the initial stage, and then it rises to 1.2m.

2. Stocking. Stocking is generally done from the end of April to the beginning of June. Most of the seedlings are common soil seedlings, priced at 500,000 to 900 yuan per 10,000 fish, and the stocking density is 100,000 to 120,000 fish per mu. Most of the seedling trials are conducted at the nursery, and water quality testing is less common. After half a month, the seedlings are harvested for observation. If the survival rate is low, additional seedlings are added, ranging from 30,000 to 60,000 fish per mu.

3. Feeding. Do not feed or feed less after stocking. Start feeding No. 0 feed one month later, feeding 0.2-0.3 catties/(mu・day). In the early stage, feed once a day, and the feeding amount will increase day by day. After a week, switch to two meals a day. About 50 days after stocking, feed 2-3 catties/(mu・day). The peak is reached in the high temperature period in July, about 12 catties/(mu・day), and then reduce the feed according to the situation.

4. Water quality management. Before stocking, use organic acid for detoxification. After stocking, like fertilized water and gradually accept the use of soluble organic fertilizers. Bacillus, lactic acid bacteria and EM compound bacteria are used more. Water quality testing is less common, and only the nitrite index in the later stage is concerned. Like yellow-green water, extremely hate blue algae water, once found, use a large amount of copper sulfate or blue algae decomposition essence to kill algae.

5. Aerators. The oxygenation capacity of most ponds is relatively low, usually 0.6kW/mu. Taking a 10-mu pond as an example, it is generally equipped with 4 1.5kW impeller aerators. Some ponds are also equipped with 1 wave-pushing aerator in the center. Air pumps and waterwheel aerators are rarely used.

6. The seed quality is low and the stocking density is too high, which increases the seed cost and is not easy to manage, affecting the growth rate and size of the shrimp out of the pond. It is recommended to cultivate branded first-generation seedlings and reasonably reduce the stocking density to 35,000-40,000 per mu, so as to remove shrimp before "filling the pond" to reduce risks.

7. Feed early. It is recommended to start feeding starter feed after stocking to ensure nutritional supply during the seedling stage, give full play to the growth characteristics of the seedlings, and appropriately add some feed additives that promote digestion, such as Bacillus subtilis, to reduce the feed coefficient, reduce feed waste, and delay the deterioration of the bottom quality.

8. Slow down the aging of water quality, use soluble organic fertilizers, and adjust water quality with bacterial preparations. Use less or no compound fertilizers, and never use farmyard manure. Water quality is seriously aged during high temperature periods, which greatly reduces the solubility of oxygen, and zooplankton will also increase oxygen consumption. Therefore, set up a reservoir, change water more often, optimize the algae structure, ensure the supply of dissolved oxygen to shrimp, and slow down the death of shrimp.

9. The oxygenation capacity is weak, which is seriously inconsistent with the stocking density, so the problems of enteritis and white stool during the high temperature period are serious. It is recommended to reduce the breeding density while improving the oxygenation capacity, configure an oxygenation capacity of 1.0kW/mu, and optimize the oxygenation configuration when conditions permit, and match a variety of aerators to improve the oxygenation efficiency.

10. Early shrimp production and shortened breeding cycle. The water environment and bottom quality deteriorated seriously in the later period, and organic matter accumulated in large quantities, which is not conducive to shrimp farming. It is recommended to reduce the stocking density, feed properly, shorten the breeding cycle, and produce shrimp early.

3. What is the reason why the feces of white shrimp are long and draggy?

There are many reasons for this, including algae toxins, eating moss, bad feed, and mainly bad liver.

Generally, it is caused by poor digestion, high residual protein, and high viscosity, which leads to loose stools.

Shrimp Intestinal Liver Ning can be mixed with feed and fed to the shrimp. Under normal circumstances, it will only take three days to use.

Enteritis, white stool, quick treatment will cure in 3-5 days

4. Why does the hepatopancreas of Penaeus vannamei always have problems? How to maintain the health of the hepatopancreas of shrimp?

The digestive gland of shrimp is a large and dense gland. Since the liver and pancreas have not been completely separated, they are collectively called the hepatopancreas. The main function of the hepatopancreas is to secrete digestive enzymes, digest and absorb nutrients. Whether the hepatopancreas is normal or not is a very important indicator of the health of shrimp.

When viral diseases such as white spot virus (WSSV) and Taurus virus (TSV) were rampant in China's shrimp farming industry, few farmers paid attention to the hepatopancreas of shrimp. However, in recent years, various diseases caused by hepatopancreas enlargement, atrophy, blurring, discoloration and other lesions have caused serious losses to farmers. Protecting the liver has become a problem that cannot be ignored in shrimp farming.

Why has the shrimp hepatopancreas been so fragile and vulnerable in recent years? There are several main reasons.

The first is the breeding of shrimp. The current breeding of shrimp only focuses on resistance to viral diseases and growth rate, while ignoring the strengthening of the digestive system and the improvement of immunity. Under the condition of energy conservation, the strengthening of one aspect will inevitably lead to the weakening of other aspects.

The second is the deterioration of the breeding environment. Currently, agricultural wastewater in China has exceeded industrial wastewater, which means that the overall agriculture, including breeding, has been developing at the cost of environmental damage. Moreover, the deterioration of China's ecological environment has reached an alarming level.

Third, the increase in aquaculture density and the widespread use of compound feeds have ignored or unilaterally replaced the positive effects of phytoplankton and zooplankton on shrimp and water bodies during aquaculture. It is precisely because of the existence of many objective reasons that liver protection has become a routine issue throughout the entire aquaculture process.

Correct and effective liver protection for white shrimp requires the following aspects:

1. Comparison between normal liver and abnormal liver

Normal white shrimp livers are generally yellow-brown, and are often affected by the color of food. A healthy liver has a white membrane at the bottom, which is connected to the stomach through the white membrane. Abnormal white shrimp livers turn red, white, swollen, or atrophic and eroded, with soft tissue and lack of elasticity. Under a microscope, diseased liver cells are unevenly arranged, and some or most of them are fatty and oily.

The process of liver disease can be observed with the naked eye, and the color usually shows: yellow-brown (normal), light red, dark red (swelling, early stage), slightly white (starting to shrink), completely white (erosion, late stage). The disease can be effectively prevented and treated in the early stage. Once it enters the late stage, the liver will turn white, shrink and erode, and white shrimps will often suffer from enteritis, yellow gill disease, black gill disease, gill rot disease, red body disease, white spot disease and other diseases. Viral diseases are especially difficult to treat. The best case scenario is to keep the shrimps with milder diseases and healthier ones, and the losses are often relatively large.

2. Correct and effective liver protection process

1. Strengthen nutrition - provide the internal material basis for liver protection

White shrimp liver protection should start from the shrimp seedlings. Starting from the second day of seedlings, continuous feeding of shrimp flakes or yeast and other high-nutritional starter feeds can ensure the nutritional needs of shrimp, which is conducive to the healthy development of the liver and lays a good nutritional foundation for the normal transition period. With sufficient and comprehensive nutrition, the shrimp body can synthesize the substances needed for liver development. In many cases, the absorption of nutrients is mutually reinforcing. For example, some vitamins are conducive to the absorption of mineral elements, so nutrition must be comprehensive.

2. Liver transfer period - smooth liver transfer is the key to successful breeding

The liver transition period of shrimp usually refers to the process of changing from natural bait to artificial feed. Due to the change in diet, the burden on the liver increases, and the liver is also in a rapid growth and development process. Oral liver protection has a good effect, but the shrimp's food intake is still very small after the start of feeding. If the liver transition is promoted by oral liver protection drugs alone, the effect is generally not significant. It is recommended that 1-2 days before and after the shrimp is started (usually about 20-25 days for the first batch of shrimp and about 18-20 days for the second batch of shrimp), on the premise of strengthening the improvement of the pond environment, the feed should be mixed with liver protection products that are less irritating and easily absorbed by white shrimp. Bile acid is the best and has the most obvious effect on promoting liver transition. At this stage, the liver sign changes to the formation of a clear white capsule, and the organ function gradually tends to be perfect. Adding bile acid to aquatic animal feed or aquaculture water can improve the immunity and disease resistance of aquatic animals. Bile acid can effectively prevent and treat inflammation of the hepatopancreas of shrimp, which has been verified in other aquatic animals. Bile acids can help create an environment in the gastrointestinal tract of fish that can kill and digest certain bacteria and viruses. Bile acids have a strong inhibitory effect on acute and chronic inflammation. Bile acids also have a significant antibacterial effect on Gram-positive bacteria and Staphylococcus aureus cultured in vitro. Liu Yufang et al. (1998) conducted an antibacterial experiment using bile acids extracted from the gallbladder of grass carp. The results showed that bile salts had a significant inhibitory effect on three Gram-negative bacteria (Staphylococcus aureus, Sarcina lutea and Bacillus subtilis) in the intestines of grass carp.

3. Regular liver care - prevent recurrence, a healthy liver requires long-term care

The shrimp's food intake increases after the liver is transferred. Although the liver has adapted to artificial compound feed, it is still under great pressure because it bears many tasks such as digestion, detoxification, and immune regulation. Adverse symptoms such as red liver and anorexia often occur. It is recommended to mix liver-protecting bile acid every 10 days (from the liver transfer period to the sale of shrimp) to prevent recurrent liver lesions and other problems, maintain the normal physiological function of the liver, and enhance digestion, absorption and detoxification capabilities.

In addition, practice has shown that a healthy liver is usually not prone to producing "white feces", so preventing "white feces" in shrimp should start with maintaining the liver.

4. Strictly control the intake of food - reduce the burden on the liver and help maintain and stabilize the liver

Many farmers are a bit impatient during the breeding process and often feed too much. Feeding too much will greatly increase the burden on the shrimp liver and pollute the water quality and bottom of the pond. The shrimp are easily stressed and even sick. This is why the shrimps often die first in shrimp ponds. Therefore, strict feed control can effectively reduce the burden on the shrimp liver and is especially important for liver protection.

5. Environmental improvement - providing a good environment for the development and growth of the liver

Compared with fish, the requirements of the environment for the growth of white shrimp are very high, even harsh, especially for the liver. Many environmental changes are often first manifested in the shrimp's whiskers, shrimp tails, and liver. A good environment is an important external condition for the smooth and rapid development and growth of shrimp livers and successful liver transfer. Therefore, it is necessary to regularly improve the water quality and bottom environment, and often cultivate water to keep the shrimp pond in a benign material cycle and form a dynamic and stable ecosystem.