Due to the disease, the success rate of shrimp farming is very low

According to the Vietnam Association of Seafood Exporters and Producers (VASEP), the success rate in shrimp farming is currently low, at only about 40%.

Prof. Dr. Dang Thi Hoang Oanh, a lecturer at Can Tho University’s School of Fisheries, said that in 2022, a group of dangerous diseases in shrimp caused by microspores called EHP will emerge in the Mekong Delta and will lead to the death of shrimp but slow shrimp growth. In terms of yield, or in other words, the feed conversion rate is low.

According to the observations of Prof. Dr. Dang Thi Hoang Oanh and a team of colleagues from Can Tho University found a phenomenon of co-infection with a number of other pathogens in addition to EHP infection. This is one of the reasons that should be recognized and carefully evaluated in shrimp farming.

Prof. Dr. Reporting on the causes of dangerous diseases in shrimp, Dang Thi Hoang Oanh said that two kinds of white spot disease and acute hepatopancreatic necrosis have recently occurred. Although they are not subject to reporting to the World Organization for Animal Health, they have been present in our country for a long time. These two dangerous shrimp diseases emerged at opposite times.

White spot disease occurs during mildly low temperature periods, while acute hepatopancreatic necrosis occurs during high temperature months. Especially at the time of the change of season, the probability of an outbreak of one of these two dangerous diseases is very high.

In addition, shrimp farming is often coinfected with many diseases caused by the unfavorable influence of weather and environmental factors, which are conducive to disease outbreaks. Therefore, in addition to the weather factor, the water environment also has a great influence on the disease outbreak in shrimp farming today.

Farmers often cultivate at high density, so pathogens spread very quickly. In addition, dead shrimp and uneaten food will form organic matter on the bottom of the pond, creating a poor environment and favorable conditions for disease development, so intensive high-density farming will make disease control very difficult. .

The prospect of using herbs to prevent disease in shrimp

Also according to Prof. Dr. Dang Thi Hoang Oanh shrimp is a low evolutionary object with no immune memory and short breeding period, so there is not much hope for preventive vaccines.

Therefore, the professor believes that shrimp farmers should focus on disease prevention rather than disease treatment. When pathogens appear, the treatment is no longer effective, because when diseased shrimp stop eating, even if they mix medicines, they will not eat and will sink to the bottom of the pond. The more difficult they are to detect, the faster the pathogen spreads. Therefore, early detection of the disease is of great importance.

Currently, most breeders are white leg shrimp and a few black tiger shrimp. Scientists have not yet developed a standard process that depends on the cultivation area and the cultivation model. Biosecurity measures and disease prevention should be a top priority.

According to many scientists, the problem of researching and using medicinal herbs (herbs) in shrimp farming is almost a trend at the moment. In our country there are many herbs that are easy to find. In particular, there are some species that are used frequently and for a long time not only for shrimp but also for fish. For example, garlic or neem leaves used in fish farming and some commercial products also contain ingredients derived from herbs.

Prof. Dr. Dang Thi Hoang Oanh also said that herbs need to be used often and for a long time when used. For the effectiveness of this method, scientists evaluate the mortality rate compared to the extent of infection or weight gain.

However, the methods and materials used are different in each case, so it is possible to be successful in one place but not in another. However, the use of herbs in aquaculture, especially in shrimp, still shows promise.