Defensive fish cold damage practical technology

Defensive fish cold damage practical technology

1, fish pond choice.
Choose the leeward sunny winter (more than 2 meters) fish pond natural wintering. Wintering pool water should not be static for a long time. Usually 20-30 days, replace some pool water, change the pool water every 1/4 to 1/5 to prevent pool water pollution.

2, set the wind wall, shelter hole.

On the north side of the fish pond, a 2-meter-high windshield can be built with straw or mud, and the south slope on both sides of the pond can be formed into a dome shape to reduce the north wind. When the cold wave strikes, the water temperature will not drop significantly. Drains should be built around the fish ponds to prevent pool water from flowing into the pool and reduce the pool water temperature.

The wall of the north wind wall can be excavated from the bottom 40 centimeters from the bottom of the pool to 1-2 deep cold caves with a depth of 2 meters and a diameter of 0.8 meters. The walls of the cave can be bricked or buried with ceramic tubes. When the cold wave strikes, the fish can avoid cold caves.

3, build plastic film cold shelter.

On the basis of setting up a wind wall, a plastic greenhouse insulation is built on the fish pond. Use a bamboo or wood along the edge of the pond to take a “person” shaped roof. The distance from the ground to the roof is about 2.5 meters. Cover with two plastic membranes and connect with the pool to form a sealing cover. The mud can be used to seal the membrane. Tilapia wintering ponds generally cover an area of ​​40-100 square meters, with a water depth of 2 meters or more, cement pools and earthen ponds, and the stocking densities may depend on the water temperature, water quality, and water volume. Generally, 15-25 tails of broodstock can be placed per cubic meter of water. Or 300 species with less than 10cm in diameter. If the condition is better, 30-40 broodstock and 400-500 species of fish can be placed per cubic metre of water. The flow pool can refer to the high-density stocking rate of water culture and can make the pool water-soluble. Oxygen should be maintained at 2 mg/l. When wintering outdoors, young crickets have a mortality rate of 70%-80% under the condition of having insulation measures. Therefore, under certain conditions, it is advisable for the juveniles to move into the indoor pool for wintering or cover the plastic sheds in the outdoor pool for wintering. The stocking density is about 100 eggs per square meter. If the management is good, the survival rate for overwintering can reach 80% - 90%.

When the plastic film greenhouse is used for wintering, it can be covered with thick grass curtains at night or on rainy days to maintain the temperature inside the shed. On sunny days, straw huts and other objects should be opened to increase the temperature using solar energy. Temperature: When the water temperature is too high, it should be ventilated and replaced with some new water. In the event of cold currents and the water temperature decreases, the following warming measures may be taken:

(1) The steam heating method adds a stove beside the wintering pond, and boils the water with an iron pan, so that the steam is fed into the overwintering pool through the connected hose from the special bamboo tub on the lid and the temperature of the pool water is increased. (2) Infrared lamp heating method In the above-mentioned wintering pool covered with a sealed plastic film greenhouse, one 250-watt infrared light bulb is installed per 35 square meters of water surface, 30 centimeters from the water surface, and a distance of about 60 centimeters above the bulb, fixing an easy one. A dry, absorbent, thick paper or other absorbent material that prevents condensation of water vapor on the film falls on the bulb, causing the bulb to burst or misfire. When the water temperature rises to 20°C, turn off the lights. The use of infrared heating benefits: infrared lamps, large heat, warming faster, less electricity, simple installation, as well as bactericidal effect, can prevent the occurrence of mildew Tilapia.

4, regular, quantitative, qualitative delivery fine material.

Although the metabolic level of fish is low during the winter, it still needs to consume a lot of energy, so during the wintering period, feeding is still an indispensable task. The main purpose of wintering is not to increase the weight of the fish, but to prevent frostbite and death of the fish, and to maintain the health of the fish. In order to prevent the decline of winter fish stocks and enhance the fish's own stress resistance, we must work hard on the selection of feeds. Preparation of feed should pay attention to a comprehensive and reasonable nutrition, one-sided pursuit of high protein content and excessive growth rate, but should pay more attention to amino acid balance, adequate vitamins and trace elements to ensure the healthy growth of fish. For example, the feed protein content of tilapia during the wintering period can be lower, about 20%, but the energy content should be higher, so it can be used for feeding, and it is often used with some feeds such as bran, bran, bean cake and malt. Ophelia, fresh leaves. In order to ensure safe wintering, it is necessary to strengthen its cultivation and improve its own resilience. Before and after overwintering, you need to replenish nutrients. First, you should strengthen the supplement of energy and protein: you can increase the fat content by 3%-5%, and feed as much fresh feed as possible, and then you need to supplement vitamins. And calcium, phosphorus and so on. In winter, the lack of sunlight is likely to cause calcium deficiency. In order to increase yolk deposition, more phosphorus is needed. The requirement for most of the B vitamins, vitamins A, D, E, and choline during the wintering period is greater than during the normal feeding period. Therefore, these substances should be increased in an appropriate amount to improve the cold resistance and enhance the resistance to disease. Prevent fat metabolism.

5. If the water temperature suddenly drops, it should be immediately replaced by water or other warming measures.

The invasion of cold waves often causes continuous low temperature and rain, which can easily lead to deterioration of fishpond water quality and pond fish disease. Some “old water” ponds and squid are vulnerable to anchor head lice, etc., except for changing the water and diligently opening the ground. Aerators, regular application of biocidal microbial preparations to improve water quality, but also timely application of insecticides, etc. for effective prevention and control to prevent the spread of pests and diseases.

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