How to cultivate fingerlings after autumn stocking to ensure the survival rate

Doing a good job of autumn intensive cultivation of fingerlings is the key to improving the overwintering survival rate of fingerlings.

To improve the environment, before stocking the fingerlings, release half of the original pond water and then add fresh water. Apply 150 kg of fermented manure per mu of pond, once every 9 days, for a total of 3-5 applications. Appropriately apply additional chemical fertilizer mainly consisting of nitrogen and phosphorus; generally apply 1.5-2.5 kg of urea and 3-5 kg of superphosphate per mu of pond, once about every 7 days. After each fertilization, add fresh water so that the pond water transparency remains at 20-30 cm. Every half month, use 10-15 kg of quicklime per mu of water surface, dissolve it in water and splash it over the whole pond once.

For stocking, ponds mainly cultivating grass carp fingerlings can be polycultured with about 30% silver carp, bighead carp and other fingerlings; ponds mainly cultivating silver carp and bighead carp fingerlings can be polycultured with 30% grass carp fingerlings. The ratio of silver carp to bighead carp fingerlings is 5:1. The stocking density should be determined according to conditions such as the size of the water surface, water depth, fingerling size and feed supply. Generally, for a pond with a water depth of 1.5 m, stock 3000-4000 fingerlings of about 10 cm per mu. The fingerlings stocked should be uniform in size.

Feed feeding: when raising grass carp and blunt snout bream fingerlings, pay attention to supplementing fresh green feed; when raising black carp fingerlings, add more animal feed such as snails and clams. For ponds mainly raising silver carp and bighead carp fingerlings, the fertility of the water should be moderate. In silver carp and bighead carp fingerling ponds, in addition to ensuring moderately fertile water, appropriate amounts of wheat bran, rice bran, cake meal, etc. should also be fed. Around Frost's Descent, when the water temperature drops, more concentrated feed should be added, and the daily feeding amount should be about 3% of the body weight of the pond fish. As long as the water temperature is above 7°C, feeding should continue; do not stop feeding too early, but fertilization and green feed feeding should be reduced as appropriate.

Fish disease prevention and control: persist in inspecting the pond in the morning and evening, regularly disinfect and improve the water body, feed in a way that ensures fixed time, fixed location, fixed quality and fixed quantity, and promptly remove feed residues. Feed medicated bait 2 times per month, each time for 5 consecutive days. If fish disease is found, diagnose it promptly and treat it according to the symptoms.