First, pond selection

The silver carp fry culture pond covers an area of 3-5 mu, and is rectangular with east-west direction, with the aspect ratio of 5: 4-3: 2, the average water depth 1.2- 1.5 m, and the pond slope ratio1:1.

The silver carp spawning pond covers an area of10 ~15mu, and is rectangular, with the east-west direction, the length-width ratio of 5: 4 ~ 3: 2, the average water depth of1.8 ~ 2.5m, and the pond slope ratio of1:1~.

Second, clear the pond and eliminate the wild.

Quicklime, tea residue, croton, bleaching powder and yutengqing can be used alone or in combination. In ponds with serious fish diseases, cleaning the ponds with bleaching powder or quicklime or tea residue mixed with a small amount of quicklime can improve the water quality and improve the survival rate of fry and fingerling.

1. Cleaning of lime pond: drain the pond water to about 10 ~ 20cm, and pour the wine evenly with lime slurry, with the dosage of 1 mu 100 ~ 150kg. Fish ponds with inconvenient water sources can be irrigated with water depth 1 m, and the dosage of quicklime per mu is about 250 ~ 300 kg.

Summer flowers of silver carp and the cultivation of 30-year-old large fish species

2. Tea residue cleaning pool: water depth 1m, the dosage is 80kg per 1 mu, and it is applied 10 ~ 15 days before the fry are planted. Toxicity disappears slowly at low water temperature and rapidly at high temperature. First, break the tea standard into pieces, put it in a wooden clamp or a water tank, and soak it in water at 25 degrees Celsius-day and night. When applying, increase the amount of water and pour the wine evenly into the whole pool.

3. Cleaning pool of bleaching powder: when the water depth is 1m, the dosage of bleaching powder is 25-30k g/ mu per1m. After the bleaching powder is dissolved in water, immediately pour the wine evenly all over the pond. The chlorine content of bleaching powder should be around 30%. Fish can be released after 4 ~ 5 days of bleaching powder cleaning. Bleaching powder cleaning is related to pond water fertility, and the effect of water and fertilizer is poor.

Third, fry cultivation.

1, pond fertilization to improve water quality: the role of fertilization is to cultivate all kinds of plankton in the water and produce open bait after the fry enter the pond.

After disinfection and clearing for 2-3 days, apply 500 kilograms of fermentation fertilizer per mu, or 2000 kilograms of green manure or 20 kilograms of urea and 20 kilograms of phosphate fertilizer per mu to cultivate plankton. 5-7 days after fertilization, the reproduction of rotifers and plankton reached its peak.

Effect of fertilization: after fertilization in the pond, the dominant population of plankton appears first, which is related to the nature of fertilizer. In the case of applying organic fertilizer, phytoplankton-Phaeocystis and Cryptophyta, zooplankton-tail caterpillar and pericaterpillar first appeared in large numbers. When inorganic fertilizers are applied, diatoms, scenedesmus and spring worms become the main populations.

When the amount of fertilizer is large, some kinds of green algae and cyanobacteria will develop in large quantities, while when the amount of fertilizer is small, many kinds of diatoms, such as spindle diatom and disk diatom, will become dominant species.

Zooplankton can reach its peak in 4 ~ 5 days after fertilization. Zooplankton first appeared in large numbers, including protozoa and rotifers, then cladocera, and then copepods.

After fertilization, if the pool water is light green and brown, algae, protozoa and rotifers will multiply in large numbers, and cladocera has just appeared, which is most suitable for the growth of bighead carp fry.

2. Time of fry entering the pond: The fry of silver carp should enter the pond on the 5th to 7th day after fertilization, which is the peak period of rotifers and cladocera.

Feed 1 cooked egg yolk for every 65438+ 100000 fry when releasing the fry, depending on the fullness in the pond. Feed soybean milk from the next day, and grind 2 ~ 3 kg of soybean into soybean milk every day per 1 mu of water surface, 2 ~ 3 times.

3. Stocking fry: The fatness should be moderate when entering the pool. First of all, put the fry in the pond into the fry box and feed them with cooked egg yolk. The feeding amount is 65438+ 100000, 1 cooked egg yolk. Feeding cooked egg yolk should be carried out according to the following steps:

1), boil the egg yolk for a long time, wrap the egg yolk with 60 mesh nylon screen wire, shake it evenly in a basin filled with water and wash it, and don't pinch it with your hands, so that the egg yolk particles can be separated from the screen in the water.

2) Pour the egg yolk water evenly into the frying box with your fingers. Half an hour later, you can see that there are egg yolk particles (commonly known as flower sausages) in the intestine of Megalobrama amblycephala larvae.

3) The larvae are put into the pond after 3-4 hours in the fry box.

4. Stocking density: Generally, the stocking density is 0/.5-200,000 per mu/kloc-0. If the fry grow to 2-2.5 cm in length, the stocking density can be increased to 250,000-300,000 per mu.

5. Feeding fry: At first, when the fish is too young, it mainly swallows plankton such as rotifers and cladocera in the water, so it should be put into the pond with fertilizer. Before the fry enter the pond, organic fertilizer should be applied to cultivate bait organisms. Then, the soybean milk feeding method is adopted, and part of soybean milk wine is fed into the pond by fry, and most of it plays a role in fertilizing water. Generally, feed 4 ~ 6 kg of soybean meal per mu every day, and increase it to 8 ~ 10 kg after the week. According to the water color, the dosage is controlled, and the water silly boy is 30: 1.

Within 5 ~ 7 days after the fry enter the pond, soybean milk is mainly fed. When grinding soybean milk, let the soybean swell, and remove the bean dregs after grinding. When feeding, the wine slurry should be wound around the edge of the pool twice, so that the wine slurry can be evenly distributed like raindrops. Feed refined powder, rice bran, wheat bran and other powdered refined feed after 5-7 days. Vote twice a day, at 9 am and 4 pm respectively.

After 25 ~ 30 days of cultivation, the fry size can reach more than 3.3 cm, and the daily feeding amount is 15 ~ 20% of the fish weight.

6. Water injection in stages: inject new water into the pond in stages to raise the water level of the pond, so as to increase the oxygen content in the water, improve the water quality, expand the activity space of fry and accelerate the growth of fish. Promote plankton reproduction and increase live bait.

When the fry enter the pond, the depth of the pond water is about 0.6 ~ 0.7 m, and after 7 ~ 15 days of cultivation, the depth of the pond water increases to 1 m. After 20 ~ 30 days of culture, the water depth of the pond increased to 65438 0.2 meters. After 40 ~ 45 days of culture, the depth of pond water increased to 65438±0.5m ..

When injecting water, use a dense mesh net to filter wild fish and pests at the water inlet, and at the same time, avoid water flowing directly into the bottom of the pool to make the pool water turbid.

7. Water quality adjustment: when the seedlings are released, the transparency of the pool water is below 30 cm, and then appropriate topdressing is carried out to control the fertility of the pool water. The transparency of pool water is controlled at about 25 ~ 30cm in summer and 35cm in autumn.

8. Pond patrol management: After the fry pass through the pond, patrol the pond three times a day to achieve three inspections? Sanle

Check the floating head of fry in the morning and catch frog eggs frequently. In the afternoon, check the activities of fry and weed the ridges frequently. Check the water quality at night, make records and arrange feeding, fertilization and water addition the next day. Check the occurrence of diseases at any time and prevent them in time.

9. Daily management: The main work is to patrol the pond once in the morning and afternoon, observe the fish activities in the pond, the change of water color and water quality, take timely measures and determine the feeding amount when problems are found, remove weeds near the pond in time, and pay attention to the cultivation and regulation of water quality. Through reasonable measures such as water injection and fertilization, the pond water is rich in palatable natural bait and sufficient dissolved oxygen.

Observe frequently to prevent floating head and fish diseases: patrol the pond in the morning and evening during the fish breeding stage. In order to prevent the lack of oxygen in the pool water due to weather changes, fresh water should be injected frequently to adjust the water quality.

10, feeding technology and feeding amount: after the body length is 2 ~ 2.5 cm, feed the powdery compound feed, and the daily feeding rate is 10 ~ 15%.

1 1. Disease control: The main diseases in the breeding stage of bighead carp fry are parasitic diseases, such as rotifers, fish lice and anchor fleas.

Prevention and control methods: regularly sprinkle the liquid medicine containing crystal trichlorfon and copper sulfate in the whole pond to make the concentration of pond water reach 0.3g//m3, and then sprinkle the liquid medicine the next day to prevent and control diseases.

12. Exercise and pond separation: After feeding for 20 ~ 25 days, the bighead carp fry grows to about 3 cm, and should be divided into ponds. Summer flower fingerlings must carry out 2 ~ 3 net-pulling exercises when they leave tang qian. Make fish species in the process of intensification, and increase the adaptability of fish to hypoxia. Make the fish mature and strong, stand out of the pond and breed alone, avoid producing a lot of mucus and feces to pollute the water quality during transportation, and improve the survival rate of transportation.

1), 1 Draw a net: Collect summer flowers in the net and check their physique. Then put it back in the pool. Because the fish is tender, so be careful in operation.

2) Second rolling difference: 1 day later, do the second rolling difference exercise. After the fish are collected, the water on the top floor automatically enters the cage. Put it back in the pool in two hours. If it is for self-support, then it can be cultivated separately after two centralized dragnets into the box.

3) Third net pulling: After the second net pulling, the third net pulling can be carried out every 1 day, and the fish can be cultured in cages in the pool with clear water quality every 1 night, and long-distance shipment can be carried out in the early morning of the next day.

Exercise fry must be done in the morning when the weather is clear and the fish are not floating. Pull the net slowly to catch the fish so as not to hurt the fry. Don't let the fish stick to the net when closing it. After the fish enters the box. Rinse the box immediately to wash away the excrement and dirt stuck on the net, so as to make the water inside and outside the box unblocked and prevent the fry from dying due to lack of oxygen in the box.