Grasp the five factors in the key to getting rich by raising shrimp

The culture mode of Penaeus vannamei is still the traditional culture model, with the further development of culture, its disadvantages are increasingly shown. The traditional culture model has been difficult to greatly increase the yield per unit area, and the comparative benefit of culture has declined; the quality of aquatic products has declined, and the culture environment has deteriorated; the occurrence of diseases is becoming more and more serious, and most of them are epidemic, so it is imperative to carry out healthy culture.

1. Stocking high quality seedlings

The vertical infection of Penaeus vannamei disease is an important way of disease transmission. Cutting off the vertical infection route and rearing healthy shrimp seedlings without virus is the fundamental guarantee of healthy culture. Therefore, it is the key to study and cultivate healthy pathogen-free seedlings. At present, Shenzhen has taken the lead in breeding highly healthy Penaeus vannamei seedlings without specific pathogens for the first time in China (also known as SPF Penaeus vannamei seedlings), but the price is relatively high, which is difficult for some farmers to accept.

2. the stocking density is reasonable.

At present, there is a common phenomenon of high density in the culture of Penaeus vannamei. There is also a common misunderstanding among farmers: that high-density seedling release can increase the yield, even if some seedlings die of disease, it can still maintain a certain density. Unexpectedly, many diseases are caused by high density. In addition, there is a problem of reasonable collocation of other cultured species, because reasonable collocation can not only make full use of culture space and improve the efficiency of culture per unit of water body, but also play an important role in improving the culture environment of water bodies, maintaining the microecology and ecological balance of water bodies, inhibiting the growth of harmful microorganisms, and maintaining the dominant position of beneficial organisms, so as to effectively prevent the occurrence of diseases.

3. Scientific management of water

The scientific management of water should first protect the internal ecological environment of shrimp ponds, and comprehensively grasp the amount of water in each stage of shrimp ponds, the amount of feed and residual bait, the content of organic matter, toxic and harmful substances such as sulfide, ammonia nitrogen and other physical and chemical factors, all of which are directly related to the survival rate and growth rate of shrimp seedlings.

Cultivating aquaculture pond water well is another important content of scientific water management. Through rational discharge and exchange of water, the cultivation of other organisms in the water body (including zooplankton, phytoplankton, aquatic plants, beneficial microorganisms, other breeding objects, etc.) and through fertilization, sprinkling microecological agents or rational use of some chemicals.

On the other hand, the scientific management of water should take measures such as precipitation, filtration and biological purification of drains to effectively remove the content of harmful substances in the waste water discharged from shrimp ponds and avoid and reduce the new pollution caused by shrimp ponds.

4. Scientific feeding

(1) pay attention to the quality of feed. It is required to use full-price compound feed instead of fresh bait. Formula feed requires comprehensive nutrition, low cost, low feed coefficient, easy to use, good food attraction, and does not pollute water quality.

(2) pay attention to the place where the feed is fed. In addition to the fixed feeding location, we should also pay attention to the appropriate setting of the number of feeding points, neither too many nor too few, so as to avoid waste of feed and pollution of water quality. The residual bait at the feeding site should be removed in time, and the feeding site should be disinfected frequently.

(3) the reasonable feeding time and times should be determined. Penaeus vannamei has the habit of going out day and night, so the bait should be fed more in the evening according to this habit of Penaeus vannamei. Generally speaking, the feeding method of a small number of times is worthy of praise. The frequency of feeding can be appropriately reduced in the season of disease outbreaks.

(4) the reasonable feeding amount should be determined. The feeding amount should be determined according to different shrimp body specifications, different culture seasons, different climates, different environmental conditions and culture conditions, rather than fixed. In general, it is appropriate not to affect the next meal intake. Be careful not to overfeed Penaeus vannamei and not to affect its growth due to insufficient food intake. In the outbreak season of the disease, it is necessary to appropriately reduce the amount of feed, which can be about 80% of the usual amount.

5. Rational use of drugs

The purpose of rational drug use is to improve the disease control effect and quality of Penaeus vannamei. Rational drug use is to use drugs in a purposeful, planned and effective way, starting from the factors of drugs, disease sources, environment, aquatic animals themselves and human health, so as to achieve the effect of preventing and treating diseases. The positive and negative effects of drugs should be recognized clearly: on the one hand, drugs can prevent and cure diseases or improve the environment and enhance the physique of aquatic animals; on the other hand, if drugs are used frequently, it will not only lead to drug resistance of pathogens, make drug control ineffective, but also poison or stimulate Penaeus vannamei and destroy the micro-ecological environment of culture water.

In the rational use of drugs, we should focus on "giving priority to prevention and combining prevention with prevention." In the peak period of the disease epidemic, according to the epidemic law of the disease, regularly feed drugs that inhibit and kill pathogens, or drugs that improve the metabolic function of Penaeus vannamei to prevent the occurrence of the disease. The common method is to mix drugs into the bait, such as adding some antibiotics or Chinese herbal medicine (such as Radix Isatidis, rhubarb, garlic, Coptis chinensis, etc.) as well as some vitamins and minerals. At present, in the process of breeding, the phenomenon of "emphasizing treatment and neglecting prevention" still exists. Once the disease occurs, drug abuse results in the increase of drug resistance of pathogens.