Five key points for autumn fingerling management, farmers need to pay attention

Autumn water temperatures are suitable, making it the peak season for fish growth. Fingerling management should focus on the following 5 tasks.

1. Pond clearing. Transfer the fingerlings to a pond that has been cleared and disinfected for rearing. Where water sources and pond rotation are difficult, all fingerlings can be transferred out temporarily for holding, then the original pond disinfected with quicklime at 75-100 kg per 667 sq m of water surface, and the water fertilized by conventional methods. Wait until the drug effect has dissipated before transferring the fingerlings back.

2. Grading. Since larger fingerlings have a big appetite and strong ability to compete for food, if large and small fingerlings are mixed, the small fish will decline in condition because they cannot get enough feed. Therefore, fingerlings should be adjusted and graded according to different sizes. Fingerlings over 6 cm can be put into adult fish ponds for polyculture, while smaller fingerlings need to be reared in dedicated ponds.

3. Sparse stocking. Raising larger-sized fingerlings in autumn is an important part of improving the overwintering survival rate of fish. Reasonable sparse stocking should be carried out according to conditions such as water surface size and water depth to promote fingerling growth. For a pond with a water depth of 1.5 m, stock 4000-6000 fingerlings of 7-8 cm body length per 667 sq m of water surface; generally, by the end of the year the fish can reach 13-17 cm in body length.

4. Feeding. In autumn, the day-night water temperature variation is small, fingerlings grow rapidly and have a large food intake, so feed supply must be guaranteed. In fingerling ponds mainly for herbivorous fish with mixed silver carp and bighead carp, green feed should be given mainly, with appropriate feeding of concentrated feed. Each day, feed 1.5-2.5 kg of small duckweed per 10,000 grass carp fingerlings. Give green feed first, then concentrated feed, to avoid grass carp competing for food with other fish. Feeding should achieve fixed quality, fixed quantity, fixed time and fixed location. For the mixed silver carp and bighead carp, fertilizer needs to be applied regularly, once every 10-15 days, applying 70-90 kg of fermented human and livestock manure per 667 sq m of water surface. Keep pond water transparency at 30-35 cm. In fingerling ponds mainly for silver carp and bighead carp with mixed grass carp, fertilizer should be the main method and feeding supplementary. In addition to base fertilizer, apply topdressing once every 5-10 days, applying 80-100 kg of rotted human and livestock manure per 667 sq m of water surface. At the same time, feed 2-4 kg of concentrated feed per 10,000 fingerlings each day; for the mixed grass carp, before feeding concentrated feed, feed 60-90 kg of green feed per 10,000 grass carp.

5. Pond patrol. During fingerling rearing, persist in patrolling the pond every day, observe the feeding and living conditions of the fish, and frequently change new water, adding and changing new water once a week. The feeding area should be cleaned frequently, and residual scraps and leftover bait removed promptly. Every half month, splash 0.5 kg of bleaching powder mixed with water around the feeding area. If diseased or dead fish are found, remove them promptly and bury them deeply, and quickly confirm the diagnosis and give medication treatment.