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. therefore, we must grasp the following points.

First, bait grass parent fish are mainly fed with grass and concentrate. According to the source of grass, grass should be fed on a fixed table when grass is thrown in the morning and concentrate in the afternoon. When green fodder is lacking in early spring, grass carp can be fed with some wheat, grain sprout, lettuce or green vegetable leaves, and ryegrass and water grass will be fed in the later stage. The feeding amount is 2%-4% of the fish's body weight and eaten in 2 hours. Parent fish 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, and can be stopped one month before the induction of labor, if the water quality is fatter.

Second, fertilizing silver carp and bighead carp parent ponds are generally based on fertilization, applying organic fertilizer once every 7 to 10 days, 100kg and 150kg per mu, using sprinkling method, such as lack of organic fertilizer, can be properly applied some chemical fertilizer, once every 5 to 7 days, about 5kg each time, fertilization should be moderate to prevent excessive anoxia flooding pond, fertilization according to the pond water quality fat and thin degree, flexible grasp. 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, adjust the water quality after the beginning of spring, because the pond goes through a winter, the physical and chemical factors and plankton in the water are 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. Silver carp and bighead carp ponds are flushed every 20 days, with a depth of 3 cm and 5 cm each time; grass pond is flushed every 10 to 15 days, each time with a depth of 5 cm, and every month before spawning, it can be flushed every 2 to 3 days. The velocity of flushing should not be too fast to prevent parent fish from excessive physical exertion due to jacking water.

Fourth, pond patrol and disease prevention every day at dawn and evening, each pond patrol checks whether there is a floating head of fish, whether there is an increase or decrease in food intake and the fatness and thinness of water, and solve the problems in a timely manner. When the water temperature rises, the fish pond disinfects the food farm every 10 to 15 days. Each pond uses about 0.5 kg of bleach, dissolves it with water and spills it on and around it.