Key points of breeding parent fish in spring

After the beginning of spring, the water temperature gradually increased, especially in the prenatal stage from March to April, the fish activity strengthened, developed rapidly, and the food intake also increased. This stage is an important period of gonadal development of parent fish. Practice has proved that the cultivation of parent fish in spring is the key to the success or failure of artificial reproduction of domestic fish, so we must pay attention to the following points:

First, bait grass parent fish to feed grass and concentrate mainly. According to the source of the grass, the grass is usually fed on a fixed table in the morning and concentrate in the afternoon. When there is a lack of green fodder in early spring, grass carp can be fed with some wheat, grain sprouts, lettuce or green vegetable leaves, and later fed with ryegrass, water grass, etc., with a feeding amount of 2%-4% of the fish's body weight and finished in 2-3 hours. Herring must be fed with a certain amount of animal feed and live snail clams every 2 to 3 days. Silver carp and bighead carp are fed with powdered concentrate of 1% or 2% of fish weight every day. One month before the induction of labor, if the water quality is fatter, the feeding can be stopped.

Second, fertilizing silver carp and bighead carp parent ponds are generally based on fertilization, applying organic fertilizer once every 7-10 days, 100kg / mu each time, using sprinkling method. If the organic fertilizer is insufficient, some chemical fertilizers can be applied appropriately, once every 5-7 days, about 5 kg each time. Fertilization should be moderate to prevent excess. Fertilizer should be flexibly mastered according to the fat and thin degree of pond water quality. The water of silver carp and bighead bighead fish pond should be greenish blue and yellowish green respectively. Keep the transparency between 35cm and 40cm, and fertilizer can be stopped half a month before labor.

Third, the regulation of water quality after the beginning of spring, because the pond after a winter, physical and chemical factors in the water, plankton situation, is not conducive to energy conversion. Therefore, before starting to feed and fertilize, it is best to change the water of the parent fish pond to half, and keep the water depth of 1 meter. The parent ponds of silver carp and bighead carp were flushed once every 20 days, adding 3 centimeters of water every time, and grass ponds were flushed once every 10 to 15 days, adding 5 centimeters of water each time. One month before the induction of labor, flush every 2-3 days, flushing the flow rate should not be too fast, to prevent parent fish from excessive physical exertion due to jacking water.

Fourth, patrol the ponds and prevent diseases once a day at dawn and dusk to check whether the fish have floating heads, whether there is an increase or decrease in food intake and the fat and thin of the water, and solve the problems in time. When the water temperature rises, the fish pond disinfects the food farm every 10 to 15 days. Each pond uses about 1 jin of bleach, dissolves it with water and sprinkles it on and around the food field.