Intensive cultivation of parent fish in spring

Spring is the key period for the gonadal growth of parent fish, and the quality of parent fish cultivation at this stage is directly related to the success or failure of artificial reproduction of domestic fish, so on the basis of usual cultivation, we should pay special attention to spring cultivation.

1. Adjust the water level of the parent fish pond and increase the water temperature. Timely drainage on a sunny day to reduce the water level of the fish pond and accelerate the increase of the water temperature of the fish pond. The displacement can reduce the water level of the fish pond by about 30 cm. When cloudy and rainy days or cold air comes, fill the pool water in advance to slow down the heat dissipation.

two。 Strengthen the feeding management, put in enough feed and fertilizer. Spring is the stage of gonadal development of fish, and the food intake increases. Green parent fish ponds are mainly fed with fresh snails, clam seeds, clam meat and other high animal protein feeds, and the daily feed can account for 3% of fish body weight, supplemented with bean cakes, pellet feed and other commercial concentrate. Grass parent fish pond, mainly feed fresh and tender green fodder, daily feeding amount of 40 kg-60 kg per mu, supplemented by high protein barley malt, bean cakes and so on. Silver carp and bighead carp parent ponds mainly strengthen fertilization, which can be applied every 2-3 days, with about 60 kg of manure each time, supplemented with powdered compound feed or soybean cake milk. When the water temperature rises above 20 ℃, attention should be paid to gradually reducing until the concentrate is given to prevent the parent fish from accumulating too much fat, delaying gonadal maturation and causing dystocia.

3. Strengthen water quality management and stimulate running water. Keep the water quality fat, alive, tender and cool. The transparency of green and grass fish ponds is kept above 35 cm. Pay attention to frequent water injection, 2-3 times a month, 20 cm-30 cm each time. Silver carp, bighead carp parent pond transparency should be maintained at about 30 cm, water injection 3-4 times a month, 10 cm-20 cm each time. From late April to enter the prenatal running water stimulation stage, once a day, 2 hours-4 hours each time.

4. Actively prevent and control fish diseases and reduce the loss of parent fish. The main diseases of parent fish are printing disease, red skin disease, anchor head disease and so on. The methods of prevention and treatment are as follows: (1) 1ppm bleach or 2ppm-4ppm gallnut, sprinkle the whole pool to prevent printing disease and red skin disease. (2) Red skin disease can be treated with chloramphenicol or chloramphenicol, 5 mg per kilogram according to the body weight of the diseased fish, and smear the affected area with 1% carbonic acid. (3) to treat printing disease, 1% benzoic acid can be used to scrub the affected area. (4) Anchor head disease was killed with 0.2 ppm, 0.5 ppm, 90% crystal trichlorfon in the whole pool, which had a better control effect.