How to prevent fish disease in tilapia culture?

In tilapia culture, the most worrying thing is that the fish is sick, if it is not treated in time, it will cause serious economic losses. So how to prevent fish disease in tilapia culture?

1. Common diseases of tilapia and their prevention and treatment

1. Bacterial enteritis

Fish suffering from bacterial enteritis are black, do not eat, slow to respond, the abdominal cavity is full of yellowish ascites, anal redness and swelling and other symptoms. The survival rate of this disease is 10%. The cause of the disease is the use of low-quality feed, which reduces the resistance of fish and breeds a large number of bacteria.

The method of prevention is to thoroughly disinfect the bottom of the pond with quicklime before fish stocking, and feed it with allicin 8g kg-1 twice a day for 4 days.

2. Gill rot disease

It has the symptoms of slow swimming, hyperemia and inflammation of the skin on the inner surface of the operculum of diseased fish, swelling of Gill filaments, and even exfoliation of Gill fragments. The higher the temperature, the more likely it is to break out, and the survival rate is 20%.

The method of prevention is to sprinkle the whole pool with quicklime alternately every half month to keep the pH value of the pool water at about 8.

II. Matters needing attention in daily management of tilapia

1. Water quality control

2 days before the stocking of fish, the toxicity of the pond disappeared, and an appropriate amount of EM or photosynthetic bacteria was injected into the pond water, and every 25 days, activation treatment should be paid attention to.

New water is injected every 15 days, and the water quality is adjusted by regular water injection, drainage and water exchange, so as to ensure the relative stability and freshness of the water quality.

2. Fertilization in water body

Fertilizer should be applied regularly and the transparency of the water should be kept at 25~30cm. The frequency and quantity of fertilization should be determined according to the pond water temperature, weather conditions and pond water color. If the pond water temperature is low, reduce the number of times to increase the number of fertilization; when the pond water temperature is high, reduce the number of times of fertilization, or even no fertilization; when it is cloudy and rainy, reduce the number and number of fertilization, or even no fertilization; sunny and sunny, increase the number and quantity of fertilization; the water color is oil-green or tea-brown, reduce the number of fertilization and quantity, or even no fertilization; light water color, increase fertilization.

3. Artificial immunity

Artificial immunity such as injection, immersion, spray and oral vaccine are given to the fish to strengthen the prevention of diseases of tilapia under high temperature. However, the vaccine for disease control of tilapia is still in the development stage, and the production and application at this stage is still less.