Detailed explanation of Jian carp farming techniques, master scientific feeding and management methods

I. Rearing of large-size summer fry

Rearing of large-size summer fry refers to the process in which, after Jian carp fry are reared into tiny fry, they are immediately divided into ponds and stocked at low density, and rapidly reared for about 15-20 days into large-size fry of 5-6 cm. Large-size summer fry can immediately be used for various adult fish farming systems such as ponds, cages and enclosures, and can be reared into marketable fish within the same year.

1. Selection and preparation of nursery ponds. The selection and preparation of nursery ponds are basically the same as for fry ponds, with an area of 0.1-0.3 ha being suitable and a water depth of 1-1.2 m. Before use, they must be carefully prepared and thoroughly disinfected. 2. Application of base fertilizer. 5-7 days before stocking the fry, generally apply 4500-6000 kg of rotted manure and 3600 kg of green manure per hectare, or a mixed compost made by stacking and fermenting 4000 kg of livestock manure, 4500 kg of green manure and 80 kg of quicklime. 3. Fry stocking. Stock the fry as early as possible to extend the growth period of the fry. The stocking density is 90000-120000 fish per hectare. Monoculture of Jian carp generally does not involve polyculture with other fish species. The fry should be robust and uniform in size. 4. Feeding management. After the tiny fry are put into the pond, because the fish are still small, they still need to be fed soybean milk for a few days. The soybean milk is splashed over the pond, and the soybean residue is placed at the pond edge, fed twice a day. After a few days, switch to soybean cake paste, placed at a fixed position at the pond edge, about 3-4 kg per 10000 fish per day.

II. Rearing of one-year-old fingerlings

1. Fingerling stocking. The rearing of one-year-old Jian carp fingerlings is the process in which fry are reared into summer fry (about 3 cm), and after being divided into ponds, about 150000 are stocked per hectare to be reared into winter fingerlings or spring fingerlings. A polyculture method can also be used, mainly with Jian carp summer fry, polycultured with grass carp, silver carp, bighead carp and other fingerlings. Per hectare, 90000-100000 Jian carp fingerlings and 45000-60000 grass carp, silver carp and bighead carp fingerlings can be stocked. 2. Feeding management. Jian carp is an omnivorous fish. In addition to concentrated feed, vegetable leaves and benthic organisms are all foods they like to eat. Frequently feeding duckweed also gives very good results.

III. Adult fish farming

1. Pond conditions. The pond area should suitably be 0.3-1 ha, and should not exceed 10 ha at most. Ponds mainly rearing Jian carp should suitably be below 0.5 ha, with a water depth of 2-2.5 m, an adequate water source and good water quality. 2. Fingerling stocking and feeding management. Fingerlings are generally stocked in winter or early spring. Summer fry of the current year are stocked in May or June. The stocked fingerlings must be robust, and those stocked in the same pond are required to be of the same species and uniform in size, and stocked all at once in sufficient quantity. In high-yield adult fish ponds mainly rearing carp, 12000-18000 carp fingerlings can be stocked per hectare, with a small number of silver carp and bighead carp as supplementary stocking, and the yield can reach about 7500 kg. 3. Supplementary stocking of Jian carp. In adult fish production, Jian carp is generally used as a supplementary cultured species. In high-yield adult fish ponds mainly rearing silver carp, ponds with abundant fertilizer sources and relatively fertile water can mainly rear silver carp. The stocking proportions are roughly: silver carp 60%, bighead carp no more than 10%, grass carp 10%, bream and wuchang bream no more than 10%, and Jian carp 10%. In high-yield adult fish ponds mainly rearing grass carp, in areas with abundant water sources, rich aquatic and terrestrial grass resources, or low-priced and sufficient supplies of grass carp pellet feed, grass carp can be the main species. Grass carp and Wuchang bream account for 60%, bighead carp 25%, silver carp 5%, and Jian carp 10%. In high-yield adult fish ponds mainly rearing black carp, in areas near large lakes and rich in snails and clams, black carp can be the main rearing target. However, carp and black carp feed on the same feed, and there is a certain conflict between the two in terms of food. Therefore, in ponds mainly rearing black carp, the stocking size of carp should be smaller, preferably 10-15 cm, and the number should not be too large.