Grass carp fish disease has always been a problem for many farmers, especially the high incidence of grass carp fingerlings in the winter, resulting in very large losses. In the past three years, the outbreak rule of fish disease has been basically the same, but this year's grass carp disease and the resulting death may be even more serious.
1, the characteristics of grass carp disease:
(1) Time of occurrence of disease: Grass carp has four peaks of onset in 2012, which are on April 15-25, May 7-15, May 20-May 3, and June 10 respectively. - July 5. The overall incidence in 2013 was better than in 2012, but the onset time was basically the same, and the peak of the first wave was around April 15.
(2) The species of grass carp disease: In the peak period of each disease in recent years, the diagnosis of grass carp disease shows that the disease types are basically the same. The symptoms at the peak of the first disease were mainly white, rotten and green livers at the end of the caudal fins, accompanied by the detection of trichoderma and ringworm. The second wave disease was mainly viral bleeding and bacterial gills. The third and fourth times were mainly bacterial enteritis and viral bleeding.
2, the cause of a large number of outbreaks:
(1) There are many rainy weather and large temperature changes: According to weather records, taking Xiantao in Hubei as an example, the rainy days in March this year were 11 days, which is basically the same as in 2012 and 2 days more than in 2013. The rainy days in April exceeded 10 days, while the rainy days in April 2013 were only 7 days. The sudden drop in rain temperature, the sudden increase in sunny weather, and the wide range of temperature changes can cause an outbreak of fish disease.
(2) The time for releasing seedlings is late, and when the seedlings are released, the temperature is high: Due to the impact of fish prices last year, many aquaculture farmers were unable to dry their ponds at the end of the year, and released their seedlings after the dry ponds in February and March of this year. The seedlings are highly damaged by the seedlings, and due to the tight time of the seedlings and the incomplete treatment of the ponds, they can cause serious fish diseases.
(3) On the night of feeding, the water body is green and cloudy: There are more users who put seedlings after the Spring Festival this year, and the water body of ponds is cloudy after release. The water mainly contains yellow turbidity and green turbid water. This type of water body has low dissolved oxygen and many suspended substances. The influence of the fish's crotch caused an outbreak of gloom. Last year, the market price of fish was poor. In the winter, the feed was delayed for a long time. The body of the fish was severely dropped and the constitution was reduced. This year, the seedlings were released later this year. After the seedlings were released, the feeding time was 15 days later than last year. The length of the fish was long. No time to eat, internal health care measures can not be implemented, resulting in decreased resistance of fish.
3, grass carp disease prevention and control:
(1) Correct diagnosis and symptomatic treatment: In April of each year, the disease basically consists of gills and rotten tails. With the infection of ringworm and trichodin, the method of drug use should be determined based on the diagnosis results. At this time the light is weak, algae growth is slow, the water body is difficult to fat, generally yellow turbidity, green turbid water-based, it is recommended before the first clean water treatment, water treatment and recovery of the rot rot, the effect of killing the parasite will Strengthened.
(2) The use of drugs is mainly based on internal medicine and supplemented by health care. Antibiotics are used with caution. After a wintering period, the body of the fish is wasted and the liver function is decreased. The specific manifestation is that the tail of the fish is whitish and the liver is green in different degrees. At this time, the focus should be on the rapid restoration of fish constitution. Therefore, in terms of disease prevention and control measures, the water should be used for insecticidal and bactericidal purposes to reduce the number of pathogens in the water and reduce the chance of infection. At the same time, feed supplements should be used in time. Intestines protect liver products, restore intestinal digestive function, and strengthen liver function recovery. In this case, the treatment of bacterial diseases such as gill and tail, if used with internal antibiotic treatment, will increase the liver load and also affect the recovery of liver function, which may cause long-term subsequent death.
(3) Maintain water stability and feeding stability to reduce stress on fish: In April and May, unstable weather and large temperature changes will cause drastic changes in water temperature and pH. It is necessary to timely fertilizer and water and enhance the buffer of the water body. Ability (such as using quicklime, etc.) In addition, special attention should be paid to the feeding during rainy weather, to keep the water body fresh and high dissolved oxygen, to ensure the smooth feeding during rainy days, in order to protect the normal use of fish ingestion and health products, rapid recovery of fish constitution. Also pay attention to the feeding rhythm when the weather turns fine. Do not add too fast, so as not to increase the digestive load and damage the liver function.
roadside emergency kit is a life-saving investment, for all vehicles. Top quality, heavy duty.The complete emergency kit can be used for car, SUV, truck, RV, or company fleet & has everything you may need for long road trips or daily driving to face & survive any emergency situation.
Car Emergency Kit,Automotive Safety Kit,Roadside Emergency Kit,Emergency Car Safety Kit
Ningbo Zhihao Car Accessories Co.,Ltd. , https://www.zhihaoautoparts.com