The cultivation of fish fingerling in autumn

The range of water temperature in autumn is generally between 20 ℃ and 30 ℃, which is a good time for fish growth, especially for fish species with small size and poor physique, so farmers must strengthen the cultivation of fish species.

After several months of breeding in spring and summer, the water quality gradually aged, the dissolved oxygen and biological bait decreased, and the number of pathogenic microorganisms increased, which will stagnate the growth of fish fingers. in particular, grass carp are more likely to get sick in such old ponds. At this time, the fish species should be transferred to the new pond for intensive cultivation. In places where there is a lack of water, Dora can net several times to transfer all the fish species out, use the water in the original fish pond, disinfect it with 30 to 40 kilograms of quicklime per mu, and use conventional methods to fertilize the water quality, and then put the fish species into the pond.

Size classification, reasonable collocation of fish species for intensive cultivation, different specifications of fish species should be released in separate ponds, and different species of fish species should be reasonably matched. For example, the pond dominated by silver carp and bighead carp can be matched with 30% grass carp, and the pond dominated by grass carp can be matched with 30% silver carp and bighead carp. The suitable proportion of silver carp and bighead carp is 5 ∶ 1. If the size of bighead carp is small, the proportion can be reduced, otherwise it will not grow up. In the ponds where these three kinds of fish are cultivated, the stocking density of fish species should not be too large. In general, the pond with a water depth of about 1.5 meters per mu should put 3000 to 5000 fish per mu.

Reasonable fertilization, strengthen bait to cultivate silver carp, bighead carp-based fish ponds, more fertilizer should be applied to ensure the proper fertility of the water body, and properly put in some concentrate feed. The method is as follows: apply human and animal manure or chemical fertilizer every 2-3 days, sprinkle about 50 kg of wet manure each time, and apply 5-8 kg per mu according to the ratio of 1 ∶ of nitrogen, phosphorus and potassium, and sprinkle evenly after dissolving in water. Concentrate feed was fed at about 9: 00 a.m. and 4: 00 p.m. Every 1000 fish were fed with 0.25 kg of wheat bran, rice bran, bean cakes and so on. In order to avoid competing with silver carp and bighead carp, grass carp should be fed with green fodder such as duckweed, aquatic grass, dry grass or grass pulp, and then concentrate feed in fish ponds, which are mainly used to cultivate grass carp.

Scientific management, the prevention of fish diseases generally change fresh water once a week, each time 10-15 cm deep, in order to cultivate grass carp ponds to timely remove the residue bait, in order to keep the water quality fresh. Wash the table regularly, disinfect it with bleach every half a month, and regularly use bleach and copper sulfate to hang baskets and bags in the pool. Insist on patrolling the pond every day to observe the eating and activity of the fish in the pond. Once the dead fish are found, they should be fished out in time for examination and medication should be used to treat the symptoms.