How to manage fish fingerlings in autumn? These technical points must be mastered

(1) Pond clearing. After the beginning of autumn, the fingerlings should be transferred to a pond that has been cleared and disinfected for cultivation, so that the fingerlings can safely overwinter. Where there are difficulties in the turnover of water sources and fish ponds, all the fingerlings can be transferred out for temporary holding, and the original pond can be disinfected with 75-100 kg of quicklime per mu, the water quality can be fertilized according to conventional methods, and the fingerlings can be transferred back after the drug has dissipated.

(2) Separate rearing. The specifications of the fingerlings stocked in the same pond must be consistent. Large-sized fingerlings have a large food intake and a strong ability to compete for food. If small-sized fingerlings are stocked at the same time, the small-sized fingerlings will not get enough feed and their physique will decline. Fingerlings over 16 cm can be put into adult fish ponds for supplementary rearing, while smaller fingerlings should be cultivated in dedicated ponds.

(3) Sparse stocking. In order to improve the overwintering survival rate of fingerlings, reasonable sparse stocking should be carried out according to conditions such as water surface size and water depth. For a pond with a water depth of 1.5 m, stock 4000-6000 fingerlings 7-8 cm long per mu, and after rearing until the end of the year, the body length can reach 13-17 cm.

(4) Feeding. In fingerling ponds mainly raising grass carp fingerlings with silver carp and bighead carp as companion species, green feed should be the main feed, with an appropriate amount of concentrated feed. Every day, for every 10,000 grass carp, feed 70-90 kg of small duckweed or aquatic plants and 1.5-2.5 kg of concentrated feed. Feed the green feed first, then the concentrated feed, so as to prevent grass carp from competing for food with other fish. For the silver carp and bighead carp that can be mixed in, fertilizer must also be applied regularly, once every 10-15 days, with 70-90 kg of fermented human and livestock manure per mu. The pond water transparency should be kept at 30-35 cm. In fingerling ponds mainly raising silver carp and bighead carp fingerlings with grass carp as a companion species, fertilization should be the main method and feeding supplementary. In addition to applying base fertilizer, apply topdressing once every 5-10 days, with 80-100 kg of decomposed human and livestock manure per mu. At the same time, feed 2-4 kg of concentrated feed per 10,000 fingerlings every day. For the companion grass carp, it is appropriate to feed 60-90 kg of green feed per 10,000 grass carp before feeding the concentrated feed.

(5) Pond inspection. Persist in inspecting the pond every day, observe the feeding and activity of the fingerlings, pay attention to changes in water quality, and add and exchange new water once a week. The feeding ground should be cleaned frequently, and residual scraps and leftover bait should be removed in time. Every half month, splash 0.5 kg of bleaching powder dissolved in water around the feeding ground. Regularly feed medicated bait. It is best to do this twice a month, each time for 3 consecutive days. If fish diseases are found, diagnose and treat them in time.

(6) Cold protection. First, the water of the overwintering pond should be kept at about 2 m; second, the water quality should still be kept fertile, and on relatively warm sunny days, a small amount of feeding is also needed, especially for grass carp, black carp and common carp.