Fish fingerling cultivation in autumn

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

1. Disinfect and clear the pond and transfer to the new pond: the old fish pond that breeds the fish species. After several months of feeding in spring and summer, the water quality gradually ages, the dissolved oxygen and food organisms decrease, and the number of pathogenic microorganisms increases, which will stagnate the growth of the fish species. 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 to strengthen the cultivation. In places where there is a lack of water sources, the water from the original fish ponds can be used and Dora nets several times. After all the fish species are transferred out, they are disinfected with 30-40 kilograms of quicklime per mu, and the water quality is fertilized by conventional methods before putting in the fish species.

two。 Size classification, reasonable collocation: fish species of different specifications should be released in separate ponds, and different varieties should be reasonably matched. If silver carp and bighead carp are the main species, 30% grass carp can be matched with 30% grass carp and 30% silver carp and bighead carp. The suitable proportion of silver carp to 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 ponds that cultivate three kinds of fish species, the stocking density should not be too large. In ponds with a general water depth of about 1.5m, it is appropriate to put 3000-5000 fish per mu.

3. Strengthen bait, rational fertilization: fish ponds, which are mainly to cultivate silver carp and bighead carp, should apply more fertilizer to ensure the proper fertility of the water, and properly put in some concentrate feed. Human and animal manure or chemical fertilizer can be applied every 2-3 days, about 50 kg of wet manure is sprinkled each time. The ratio of chemical fertilizer is 0.5 according to nitrogen, phosphorus and potassium, 5-8 kg per mu, dissolved in water and sprinkled evenly. Concentrate is fed at about 9:00 and 16:00 every day, and every thousand fish are fed 0.25-0.5kg of wheat bran, rice bran and bean cakes each time. Fish ponds that mainly cultivate grass carp should strengthen the feeding, first feeding green fodder such as duckweed, aquatic grass, dry grass or grass pulp, and then feeding concentrate feed to avoid grass carp competing with silver carp and bighead carp for concentrate feed.

4. Scientific management to prevent fish disease: keep patrolling the pond every day and observe the eating and activity of the fish in the pond. Pay attention to the change of water quality, change new water frequently, generally change new water once a week, 10-15 cm each time. Fish ponds, which mainly cultivate grass carp, should keep the water quality fresh, remove the residual bait in time, often scrub the table, disinfect the table with bleach every half a month or so, and regularly use bleach, copper sulfate and other drugs around the food farm to hang baskets and bags to prevent fish diseases. Fish diseases and dead fish should be fished out in time for inspection and prevention and treatment with drugs.