Recently, the temperature of gas in the main producing areas of Tilapia in Guangdong, Zhanjiang, Maoming, Shaoguan, etc. has dropped. In some areas, the temperature has dropped to 5-6 degrees. Last year, it was attacked by cold weather and caused a lot of loss to tilapia breeding. For this reason, the cold-proof work of tilapia breeding is urgently needed. Now introduce some tilapia cold protection measures for farmers reference.

Introduce hot water source

Hot spring water winter. The overwintering pond area will be determined according to the water temperature, flow and terrain, and the scale of production. The depth of wintering pond should be 1.5~2 meters, and the amount of influent water and water should be similar to maintain a certain water temperature and depth. If the water temperature of hot springs is very high, they should be cooled to a certain temperature in the reservoir and then injected into the wintering pond. This overwintering method has higher density of overwintering fish. At the same time, due to the higher water temperature and sufficient water, the broodstock breeding and breeding can be strengthened, and the gonad gonads can be precociously promoted and the breeding and nursery can be carried out earlier.

Factory overheating winter heat. Cooling water in thermal power plants is generally uncontaminated, and a large amount of warm water is discharged or recycled every day. The oxygenation of cooling water can make dissolved oxygen in water reach 5-7 mg/L, and the water temperature is generally between 16-25°C. Using this heat source for tilapia winter preservation and early reproduction, the effect is better.

The amount of feed used during the wintering period using hot water depends on the water temperature and the fish's diet. Under normal circumstances, the amount of feed generally accounts for 1% to 2% of the total weight of the fish.

When the water temperature is high, the tanks can be equipped with deep well cool water pipes to provide cool water to regulate the temperature when the pipes are introduced into the pool. In general, the feeds are bean cake powder, bran and artificial diet, etc. can be used as winter feed, the crude protein content of the food is about 25%. The daily feeding amount depends on the temperature of the water. The lower the temperature, the smaller the feeding amount. On the contrary, the higher the temperature, the greater the feeding amount. The water temperature is between 16 and 22°C, and the general feeding amount is 0.5% to 1.5% of the total fish body weight. Usually 2 shots per day, close to spring can be fed 3 times. When the farming density is relatively large, it is necessary to regularly discharge the pollutants. Commonly used sewage discharge equipment is rubber siphons and small axial flow suction pumps, and the sewage is discharged 1 to 3 times a week.

Wintering greenhouse

Plastic sheds are wintering. Firstly, arch or herringbone scaffolds are constructed of steel or bamboo. The roof is 1.8 to 2 meters above the ground. It is covered with two layers of plastic film, and the outside is pressed with bamboo, and the shed is compacted with mud. The wintering pond is selected where the leewards are sunny, the water quality is good, and the water and electricity are convenient. Overwintering pool is best to choose east-west, rectangular, area of ​​60 to 120 square meters, water depth of 2 to 2.5 meters, easy injection and drainage. This wintering method can use groundwater as a water source, keep the water temperature at 16~18°C, and have a good wintering effect, low cost, and easy promotion. If there is no groundwater, reservoirs, creek water, and electric heaters can be used to increase the water temperature. Generally, 30 cubic meters of water should be equipped with 1 to 2 electric heaters of 3 kilowatts. This method is suitable for small-scale wintering of farmers.

Winter in the glass house. The overwintering pond is cement ground, with an area of ​​50~80 square meters, and water depth of 1.5~2 meters. Overwintering pool is built around the brick wall, covered with transparent glass on top of the overwintering room.

Heating water body wintering

There are two overwintering methods, electric heating and fuel heating. Electric heating devices mainly include dilute ion submerged heaters and electric heaters, which are suitable for use in areas with sufficient power, normal power supply, and low electricity prices. The fuel heating equipment includes dedicated furnaces and heating boilers, and is suitable for use in areas where other conditions are lacking and where fuel resources are abundant, sources are convenient, and prices are low.

When using an electric heater, install the heater in the tank, and determine the number of the heater according to the size of the tank so as to maintain the water temperature. For example, an electric heater is used to warm up the winter. The production materials are mostly non-toxic high-pressure polyethylene plastic insulated heating wires with a thermal efficiency of 40%. When the room temperature is 5°C, a 3-kilowatt three-phase electric heater can be used to maintain the temperature of 25 cubic meters of water at about 20°C. This type of heater must be used in water. It is strictly forbidden to use electricity without water, otherwise it will burn out the insulator. To prevent the heater from floating upwards, increase the weight appropriately. The position in the pool should be 20 cm away from the pool wall and 20 cm from the bottom of the pool. To ensure safety must be grounded. When it is found that the wire or connector is damaged, it should be replaced and repaired in time. Switch off the power before changing the water.

Heating water with a boiler can be recycled and heated. In the production, the size of the boiler should be determined according to the size of the overwintering pond.

You can also use the stove to heat the pond directly. A stove is built next to the wintering pool, and the coal is heated directly to the wintering pond or wintering water tank. The general stove is located in the lower part of the wintering pond, and the flue of the stove heats the water through the bypass and the flue in the bottom of the pool or in the wall of the pool. The exit of the flue should have a certain height in order to increase the spread of fire and heat in the flue.

In short, farmers should not hesitate to set aside funds for building fish ponds in greenhouses, or to provide thermal facilities for fish ponds, or to drill deep wells in the pond. Once the cold weather is encountered, warming facilities can be activated to avoid losses. In addition, at the beginning of the year, many tilapia breeding bases had broken their wires due to heavy snow, which led to the power off of the base and the inability to keep tilapia warm. A large number of tilapia were frozen to death. Therefore, farmers need to release manpower to check whether the wires in the breeding base are safe and secure and prevent the tragedy from repeating itself.

Micro centrifuge tubes

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