"I feel that the fish plague has begun, and it is as ruthless as the dead fish in the summer high temperature", a friend in Huzhou, Zhejiang Province reported that on February 14, almost 60,000 catties of fish died in a fish pond of a fish farmer on their side.
Since February, there have been farmers in WeChat groups, Douyin and other short ** for help, their own fish ponds began to appear sick and dead fish, some are water mildew, some are rotten disease, and some dead fish surface can not see any problems, "at the beginning a few problems did not take seriously, and then slowly more, some fish ponds even appeared a large area of death."
Dr. Yuan Sheng, an associate professor of Jiangsu Vocational College of Agriculture and Animal Husbandry Science and Technology, who is active in the front line of breeding, said on Douyin today that wintering syndrome is about to occur on a large scale, and has recently received a number of requests for help from farmers, which are basically the problem of wintering syndrome.
Note**Screenshot from Teacher Yuan Sheng's Douyin**.
In recent years, the situation of dead fish in the beginning of spring seems to be not unusual, and farmers call it fish plague, and academically call it overwintering syndrome. Why is it called fish plague? In the early spring years, farmers along the Yangtze River found that a large number of grass carp were dying, which was very difficult to control, "it felt like the fish had a plague, and it was called fish plague", which also showed the fear of farmers about this phenomenon of dead fish.
At the beginning, the species of fish plague were mainly concentrated in grass carp, and later crucian carp, white silver carp and other species also had similar problems, and in recent years, catfish, yellow catfish, sea bass, black fish, etc. have also had such problems. There are certain differences in the statements of different people about overwintering syndrome, but the core expression has the same meaning.
In the spring of 2021, the scene of a farmer's tragic fish death.
To put it simply, this is a kind of comprehensive disease that is easy to occur in the spring, mainly harming the freshwater fish that overwinters in the pond, the main symptoms are that the eyes of the diseased fish are protruding, congested, the scales fall off, the skin is red or ulcerated, the base of the fin is congested or bleeding, and the fin rod is rotten, especially the symptoms are more, such as the fish body or the fish mouth ulcers, rotten flesh and so on.
Therefore, many people encounter different symptoms of overwintering syndrome, some are water mildew, some are rotten body disease, some are vertical scale disease, etc., most of the diseased fish actually present a variety of diseases at the same time, resulting in farmers do not know where to start with the disease, if there are professional and technical personnel to deal with the steps, there may be rescue, if you meet irresponsible or do not know how to deal with people, it may be the eyebrows and mustaches to grab, indiscriminately use drugs, the result is that the dead fish are faster, the loss is greater.
Duration: 03:59Last year, many farmers in Henan encountered this problem, and even caused a provincial TV station to publish an interview report about overwintering syndrome, the above is the news at that time**.
There are many reasons for the occurrence of overwintering syndrome, and with the changes in the breeding situation in recent years, there have been many changes in the first statement every year. In the past, it was mainly said that farmers should do a good job of prevention before wintering, resulting in poor physique of pond fish after wintering, and there are many bacteria and pathogens in spring, which are easy to get sick. In the past two years, there have been more and more problems of feed prices and quality declines, and the spearhead has been pointed at low-quality feed.
In fact, there are many reasons for inducing overwintering syndrome, if you summarize it, it is two categories, the maintenance of the external environment and the internal environment is not done well, and then many reasons are extended from these two directions.
Let's talk about the external environment first, in the middle and late stages of the last breeding cycle, the residual bait feces continue to accumulate, and the water quality of many fish ponds is relatively poor for a long time, and some people's water quality looks okay, but the bottom quality of fish ponds is very poor, and there is even a large amount of black and smelly mud. In the spring, when the temperature rises, coupled with more rain, it is easy to cause harmful substances in the pond to become more harmful, which is a trigger for the outbreak of overwintering syndrome.
The most significant feature of winter is the low temperature, there will definitely be a few days below zero in winter along the Yangtze River, and then to the north, it is common to have more than ten degrees below zero, in the state of low temperature, the fish are in a semi-dormant state, the protective effect of fish scales is weaker, and the stress and lethality brought by low temperature weather will be great, at this time, even if the fish pond is not moved, there may be problems, and if the net is pulled again, it is easy to scratch, and it is easier to cause the occurrence of overwintering syndrome.
The problem of dead fish from the farmer in Huzhou mentioned above, if you look at it from the point of view of temperature. In the past two months, the minimum temperature in Deqing most of the time is below 5 degrees, and the maximum temperature is often less than 10 degrees, and there are several consecutive days of sub-zero weather in late December, early January, and late January, with the lowest temperature of minus five or six degrees.
Speaking of the internal environment, the main problem is the resistance of pond fish, to put it bluntly, in bad conditions, it must be easier for fish with better resistance to survive. Therefore, the quality of feed before wintering should be slightly better, if you continue to feed low-quality feed at this stage, the nutrient accumulation required by the fish for wintering is not enough, and the physical condition becomes worse and easy to get sick.
In addition, when feeding feed, we should also pay attention to protecting the liver and gallbladder, feeding some health care products with mixture, maintaining the health of the liver and intestines, and appropriately using some microbial products, strengthening internal conditioning, and enhancing the resistance of pond fish. If the Tangkou is small, the artificial mixing can be done, and if the Tangkou is large, it is recommended to buy a mixer, which is not expensive and very convenient to use.
In addition, in previous years, there were farmers who occurred, after the temperature began to feed, if the feed was added violently, the situation of sick dead fish would be more serious, and the pond mouth with less late feeding was not so heavy. This situation has also appeared before the winter in Guangdong, that is, the temperature rises rapidly after a cooling, and there is an explosive death of the fish fed according to the normal feeding amount, the reason is actually similar, the material should be slowly reduced, and the feed should be added slowly, so that the fish can slowly adapt to reduce the situation of sick and dead fish.
The development of aquaculture to this day, there are still many farmers "usually do not prevent, the disease to find the miracle drug", especially in the past two years fish profits slowly declined, even special fish have a wide range of money can not make money, even the phenomenon of loss, some farmers in the disease prevention on the "saving", once the onset, the mood of wanting to buy the miracle medicine at any cost, people can not help but sigh. Even if there is a miracle drug, it is very expensive, and the cost of prevention is really low.
Judging from the incidence of overwintering syndrome in the past two years, if the protection work before wintering is okay, but it is still onset, and the condition is not so serious, if there are technical technicians, you can try to deal with it, and the signs of getting better in a few days can continue to be strengthened, and if the treatment continues to expand the incidence for a few days, it is recommended that the technology take action. If the work of feeding and health care, water quality and substrate maintenance before wintering is not done well, if it is an explosive disease, it is recommended not to spend money on treatment, in this case, the probability of the result is that a lot of money is spent, people are very tired of tossing, and eventually the fish will die almost.