Technical measures for overwintering cold prevention of farmed tilapia

Tilapia has the characteristics of omnivorous, crude, fast-growing, easy to grow, low cost and less diseases, so it is the main excellent breed in our province. However, the fish is a tropical and subtropical fish. Whenever the strong cold air moves south and the water temperature drops to about 10 ℃, there is a risk of frostbite and frostbite. The weather is getting colder, so we must do a good job of cold prevention to protect tilapia safely through the winter.

First, choose a good fish pond.

It is best to choose fish ponds near the village, fish ponds in front of your home, fish ponds on the outskirts of cities and towns, and fish ponds near sugarcane forests, bamboo forests and trees. These fish ponds generally have houses and trees on both sides of the west and north as natural barriers against the wind to prevent the attack of cold waves, and the water temperature changes little, which is conducive to overwintering. The area of fish ponds should be 2 mu and 3 mu, and the wind area is small. After the fish pond is selected, the pond should be cleaned and disinfected first to eliminate all germs and enemies, so as to create conditions for the two kinds of fish to pass the winter safely.

Second, release water in time.

Increasing the water depth to increase the water temperature of the fish ponds is the most basic work to protect the safety of farmed fish through the winter. According to years of investigation, where the water depth is more than 2.5 meters and trees are sheltered from the wind, they basically meet the requirements of thermal insulation, so it is necessary to store enough pond water as soon as possible so that the water depth can reach more than 2.5 meters. For the water surface that is inconvenient for drainage and irrigation, a "fish bed" can be dug to the west and north of the fish pond to make its water depth meet the requirements of cold prevention and winter. When the cold wave strikes, the fish in the pond are concentrated in the "fish bed" to keep warm.

Third, build a windproof and cold shelter.

For fish ponds that do not have houses or bamboo and wood to block the wind, windproof and cold shelters should be built. Wind-proof and cold-proof sheds can be made of straw or sugarcane leaves, sandwiched into grass grasses of 3 meters × 4 meters each, and then fixed with bamboo racks on the west and north sides of the fish ponds to prevent the invasion of cold waves, while the wind-proof sheds should obliquely cover the grass on the west and north water surface of the fish ponds, the front end is about 67 cm from the water surface, and the back end is close to the edge of the pond, and some straw should be thrown under the shed. When the cold wave strikes, fish can be kept warm in the grass under the canopy.

For the conservation pond of tilapia parent fish, a semicircular scaffolding is built on the edge of the pond with bamboo poles or fine steel bar, and the scaffolding is covered with thin film to make a cold-proof greenhouse. At 10:00 and 15:00 in the afternoon on a sunny day, the film should be lifted to achieve the purpose of ventilation and light transmission, and to ensure the safety of parent fish through the winter.

Fourth, dig drains.

Digging a drain with a depth of 0.5m and a width of 0.7m around the overwintering fish pond is very important, because when the cold wave goes south continuously, it often causes overcast and rainy low temperature weather. Rain Water's water temperature is lower than that of the pond. Rain Water can be drained out of the pond to keep the water temperature stable.