Fish species released in autumn and cultivated in autumn to keep them alive

Strengthening the cultivation of fish species in autumn is the key to improve the survival rate of overwintering fish species.

Improve the environment before the release of fish species, release half of the original pond water, and then add new water. 150 kg fermented manure was applied per mu pond, once every 9 days, for a total of 3-5 times. Appropriate topdressing of chemical fertilizers based on nitrogen and phosphorus, generally 1.5-2.5 kg of urea and 3-5 kg of superphosphate per mu of pond, about once every 7 days. Add fresh water after each fertilization to keep the transparency of the pool water at 20-30 cm. Sprinkle 10-15 kilograms of quicklime on each mu of water every half a month.

Fish species are put into ponds that mainly cultivate grass carp fingerling, which can be matched with about 30% of silver carp and bighead carp species, and ponds that cultivate silver carp and bighead carp fingerling, with 30% grass carp fingerling. The proportion of silver carp and bighead carp is 5 ∶ 1. Stocking density should be determined according to the size of the water surface, water depth, fish species specifications and feed supply and other conditions. Generally, in a pond with a water depth of 1.5m, there are 3000-4000 fish species of about 10cm per mu. The specifications of free-range fish should be neat.

Feed feeding grass carp, blunt snout bream fingerling, pay attention to the supplement of fresh green feed; raising herring fingerling, should add more animal feed such as Corbicula. In the ponds where silver carp and bighead carp are mainly cultured, the fertilizer and water should be moderate. Silver carp and bighead carp fry ponds should not only ensure proper fertilizer and water, but also feed appropriate amount of wheat bran, rice bran, cakes and so on. Before and after Frosts Descent, when the water temperature decreases, concentrate feed should be added, and the daily feeding amount should be 3% of the body weight of fish fry in the pond. As long as the water temperature is above 7 ℃, feeding should be persisted and should not be stopped prematurely, but fertilization and green feed feeding should be reduced as appropriate.

Fish disease prevention and control adhere to the morning and evening pond patrol, regular disinfection to improve the water body, feed to achieve timing, positioning, quality, quantitative, timely removal of feed residue. The bait was given twice a month for 5 days each time. Find fish disease, timely diagnosis, symptomatic treatment.