Summer Flower of Grass Carp and cultivation of older size Fish species

Food habits of grass carp fry

Grass carp fry stage food is mainly zooplankton, initially by protozoa, rotifers, fleas and other small zooplankton, with the growth gradually devour American fleas, cyclopsylla, plagiarizing water fleas and other large fleas.

Food habits of grass carp black carp fry

After 15-20 days of cultivation, when the body length reached 1.7~3.1cm, the throat teeth initially formed protuberances, the intestines grew and bent, and the feeding habits began to transform into the roots of Chironomus larvae, Wuping, three-leaf duckweed, purple back duckweed and other aquatic plants. As it continues to grow and develop, it enters the fish species stage.

Food habits of grass carp summer flower fingerling

Grass carp (Ctenopharyngodon idellus) switch to large plants as the staple food during full-length 5cm. Invertebrates account for a small part of the feed of grass carp with full-length 5~10cm. Adult grass carps living in natural water mainly feed on submerged plants and Gramineae plants growing in shallow coastal areas.

Pond selection

The area of grass carp fry culture pond is 3 to 5 mu, rectangular, east-west direction, length-width ratio 5, 4, 3, 2, average water depth 1.2, 1.5 meters, slope ratio 1, 1, 1.5, bottom flat, loam, silt thick 15~20cm, easy to enter and drain.

The area of grass carp fingerling culture pond is 610 mu, rectangular, east-west direction, the ratio of length to width is 5, 4, 3, 2, the average water depth is about 1.8, 2.5 meters, the slope ratio is 1, 1, 1.5, the bottom is flat, loam, silt thick 15~20cm, easy to enter and drain.

Clear the pond and remove the wild

Quicklime, tea meal, Croton, bleach and fish rattan clear can be used alone or mixed. In ponds with serious fish disease, bleach or quicklime is used to clean the ponds, or tea meal plus a small amount of quicklime to improve water quality, which plays a certain role in improving the survival rate of fish fry and fry.

1. Quicklime pond cleaning: drain the pond water to about 10~20cm and sprinkle it evenly with lime paste. The dosage is about 100kg / mu. Fish ponds with inconvenient water sources can be filled with water, with a water depth of 1 meter and about 250 kilograms of quicklime per mu.

2. Tea meal cleaning pond: the water depth is 1 meter and 80 jin per mu, and the fish fry is applied 10-15 days before lining. When the water temperature is low, the toxicity disappears slowly, and when the temperature is high, it disappears quickly. First beat the tea meal into blocks, put it into a wooden stick or water tank, soak it with water and soak it for one day and night when the water temperature is 25 ℃. Increase the amount of water during application and sprinkle evenly throughout the pool.

3. Bleach cleaning pond: when the water depth is 1 meter, the dosage of bleach is 250.30 jin / mu per mu. After the bleach is dissolved with water, it is sprinkled evenly in the whole pool immediately. The chlorine content of bleach should be about 30%. Bleach cleans the pond for 4 to 5 days and the fish can be released. The cleaning of bleaching powder is related to the fertility of pool water, and the effect of water and fertilizer is poor.

Fish fry cultivation

1. Fertilizing and improving water quality in the pond: the function of fertilization is to cultivate all kinds of plankton in the water and produce the open bait after the fry goes down the pond.

After 2 or 3 days of disinfection, 500 jin of fermented manure was applied per mu, or 2000 jin of green manure per mu or 20 jin of urea + 20 jin of phosphate fertilizer per mu were used to cultivate plankton. Rotifer and plankton multiplication reached the peak after 5 days of fertilization.

Fertilization effect: after fertilization in the pond, the first dominant population of plankton was related to the nature of fertilizer. With the application of organic fertilizer, phytoplankton-dinoflagellate and cryptoplankton, zooplankton-tail caterpillar and peripheral caterpillar first appeared in large quantities. Diatoms, Scenedesmus and bouncing worms became the main populations when applying inorganic fertilizer.

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

Zooplankton reached the peak 4-5 days after fertilization. The first large number of zooplankton are protozoa and rotifers, followed by Cladocera, followed by copepods.

After fertilization in the pond, if the water is light green brown, algae, protozoa and rotifers multiply in large numbers, and Cladocera is just beginning to appear, which is most suitable for the growth of grass carp fry.

2. The time of fish fry in the pond: grass carp and splash fry should be in the 5 ~ 7 days after fertilization, when the occurrence of rotifer and cladocera is at its peak.

Feed one cooked egg yolk for every 100000 fry to feed them into the pond. From the second day, feed soybean milk, grind soybean milk with 2 jin of soybeans per mu of water every day and feed it 2 times for 3 times.

3. Fish fry restocking: the larvae in the lower pond are first put into the fry box and fed with cooked egg yolk. 100000 larvae are fed with 1 cooked egg yolk. Feed the cooked egg yolk according to the following steps:

1) boil the egg yolk for a long time, wrap the egg yolk in 60-purpose nylon sieve silk, shake and filter in a basin filled with water, do not pinch it by hand, and make the yolk particles separate out of the water from the mesh.

2) pour the yolk water evenly into the fry box with your fingers, and half an hour later, you can see egg yolk particles in the intestines of the larvae (commonly known as flower sausages).

3) put the larvae into the pond after keeping them in the fry box for 3 hours.

4. Stocking density: generally, the stocking density is 15 ~ 200000 tails / mu. If the seedlings grow to full length 1.8~2.0cm, the stocking density can be increased, up to 20 ~ 250000 tails / mu.

5. Fish fry feeding: at first, the fish is too small to mainly devour rotifers, small cladocera and other plankton in the water. The fish fry should be fertilized into the pond, and organic fertilizer should be applied before the fry goes into the pond to cultivate bait organisms, and then soymilk feeding method is adopted. Soymilk is sprinkled into the pond, some of which are fed by fish fry, and most of them play the role of fertilizer and water. The amount of feed generally fed 4 kilograms of ground soybean pulp per mu every day, which increased to 8 kilograms after a week, and mastered the dosage according to the water color, the ratio of water to beans was 30:1.

Fish fry in the pond within 5-7 days, mainly fed with soybean milk, 7 days later can be fed with fine flour, rice bran, wheat bran and other concentrate feed. Three daily throws, 9: 00 a.m., 1: 00 p.m., 4: 00 p.m. When grinding soy milk, be sure to soak up the soybeans, and remove the soybean dregs after grinding. When feeding, the paste should be sprinkled twice along the edge of the pool, and the spilled pulp should be like rain and evenly distributed.

After 10 days of feeding, use soybean cake milk instead. The soybean cake was broken, soaked in water for 3 to 4 hours, and then ground into soybean cake milk with a ratio of 1:10 to water. After 25 years and 30 days of cultivation, the fry size can reach more than 3.3cm, and the daily feeding amount is 1520% of the fish body weight.

6. water injection by stages: adding new water into the pond by stages to increase 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 fish fry, and accelerate the growth of fish. Promote the reproduction of plankton and increase live bait.

When the fry entered the pond, the depth of the pond was about 0.6-0.7 meters. After 7-15 days of culture, the depth of the pond increased to 1 meter. When incubated for 20-30 days, the depth of the pool increased to 1.2 meters. After 40 days of cultivation, the depth of the pool increased to 1.5 meters. After 2 months of cultivation, the depth of the pool increased to 1.8 meters. The depth of the pool is controlled at about 1.8 to 2 meters in autumn and winter.

When injecting water, a dense net is used to filter wild miscellaneous fish and pests at the inlet, while avoiding the flow of water directly into the bottom of the pool to muddy the water.

7. Water quality regulation: when releasing seedlings, the transparency of pond water is below 30cm, and then appropriate topdressing is applied to control the fertility of pond water. The transparency of pond water is controlled around 25~30cm in summer and around 35cm in autumn.

8. pond patrol management: after the fry pond, patrol the pond three times a day to achieve "three checks" and "Sanle".

Check the floating head of fish fry in the morning, frequently catch frog eggs; check the activity of fish fry in the afternoon, remove weeds on the ridge of the pond; check the water quality in the evening, make records, and arrange bait, fertilization and water addition work the next day. Check the occurrence of the disease at any time and carry out prevention and control in time.

9. Exercise and separate ponds: after 20-25 days of feeding, grass carp seedlings grow to about 3cm and should be reared separately. Before going out of the pond, the summer flower fry should be trained for 2 or 3 times. Make the fish species in the dense process, increase the adaptability of the fish body to hypoxia. Make the fish "sophisticated" strong, can withstand separate culture out of the pond, and avoid producing a large amount of mucus and feces to pollute the water quality in the process of transportation, and improve the survival rate of transportation.

1) pull the net for the first time: gather the summer flowers in the net and check their physique. Then put it back in the pool. Because the fish is tender, the operation should be careful.

2) the second pulling net: after one day, the second pulling net exercise will be carried out. After collecting the fish, let the top water enter the cage automatically. Put it back in the pool in two hours. If it is for self-feeding, then after 2 times of pulling the net into the box, separate cultivation can be carried out.

3) pull the net for the third time: after the second time, the net can be pulled for the third time every other day, and the fish can be "suspended" for one night in the cage in the pool with cleaner water quality, and the long-distance shipment can be carried out in the early morning of the second day.

Exercise fish fry must choose fine weather, in the morning when the fish do not float head. The operation of pulling the net to drive the fish should be slow, so as not to hurt the fry. Don't let fish stick to the net when you close the net. After the fish is in the box. The box should be washed immediately to wash away the excrement and dirt of the sticky net, so that the water body inside the box and outside the box can be unblocked, so as to prevent the death of fish fry due to lack of oxygen in the box.

10. nutritional collocation at the stage of fish breeding: according to the different requirements for protein in different growth and development stages of grass carp, the following principles should be mastered:

Before the body length 5cm, the protein content in the feed should reach 40%; when the body length 6~7cm, the protein content in the feed can be reduced to 35% 30%; after the body length 10cm, the feed protein content can be reduced to 28% 25%. From the point of view of production cost and the best economic benefit, the feed protein content can be reduced appropriately. Feed should add appropriate amount of mineral salts (inorganic salts), vitamins and other additives.

11. Feeding technology and feeding amount: body length 5~8cm, which is the stage of transformation of grass carp feeding habits. In addition to feeding Wuping and duckweed, and feeding formula feed with corresponding particle size, the daily feeding rate is 10-15%.

12. Disinfection of pool water: from May to June, pond water is disinfected once a month. Commonly used drugs and dosage: bleach 1 mg / L (1.3-1.5 jin / mu); mixture of copper sulfate and ferrous sulfate 0.70 mg / L (0.9 jin / mu); trichlorfon 0.50 mg / L (0.6 jin / mu); quicklime 20 mg / L (20,25 jin / mu); all kinds of drugs used alternately.

13. Disease control: the main diseases in the seedling cultivation stage of grass carp are parasitic diseases and white-head and white-mouth disease, such as rotifer, fish lice, anchor flea and so on.

Control method: regularly sprinkle with crystal trichlorfon and copper sulfate in the whole pool to make the pool water concentration up to 0.3g/ cubic meters, and then sprinkle it again the next day to prevent and cure.

14. Physical and chemical indexes of water body during fry culture period:

1) oxygen consumption of organic matter: under the condition that there is no lack of dissolved oxygen in pond water, the oxygen consumption of organic matter is high, and the survival rate of grass carp seedlings is also high. Before the fry goes into the pond, the oxygen consumption of organic matter is more than 30 mg / L in order to ensure the fertility needed for the growth of plankton.

Fish fry after entering the pond, a large amount of plankton intake, continuous consumption of organic matter, we should continue to apply fertilizer. The amount of fertilization should be small, the times should be more, and it should be applied every 2-3 days. Some of the spilled soybean milk cultivated zooplankton, some became organic fertilizer, and only a small part was directly used by grass carp seedlings.

2) dissolved oxygen: the amount of dissolved oxygen in water is closely related to the survival of fish fry. When the dissolved oxygen in water is below 2mg/L, the fish fry will appear floating head. The amount of dissolved oxygen in water needed for the normal growth and development of grass carp fry is 4.5mg/L, and when it is reduced to 1.5mg/L, the respiration of grass carp fry is inhibited. In the process of production, grass carp fry float slightly from pre-dawn to 1-2 hours after sunrise, indicating that the water quality is too fertile and should not be applied with bait.

3) pH value: when the pond was cleaned with quicklime, the pH value and hardness of the pond water were higher, and all rotifers died, but it was harmless to rotifer winter eggs. When the pH value was below 10, a large number of rotifer winter eggs could germinate. After 8-10 days of pond cleaning, the efficacy of lime disappeared, pH decreased below 9, phytoplankton began to multiply in large numbers, and the amount of dissolved oxygen in pond water increased, often reaching saturation. At this time, a large number of rotifers appeared, and the fish fry should go into the pond in time.

One-year-old fingerling cultivation of grass carp

The process of cultivating summer flowers with body length 2.5~3.3cm into body length 20~25cm is called fish breeding, and the process can be divided into two stages:

The first-level feeding stage: the summer flowers with body length 2.5~3.3cm were cultivated into summer flowers of 7~9cm, which is called the first-level feeding stage.

Secondary feeding stage: the summer flowers with body length 7~9cm are cultivated into fish species with 20~25cm length, which is called the secondary feeding stage.

The main results are as follows: 1. In the first stage, grass carp flakes are bred into summer flowers of 2 inch (full-length 7~9cm), with 30-50 000 flakes of full-length 3cm per mu. Adopt the way of monoculture.

1) artificial bait: grass carp fire slices raised with 3cm must be filled with broken materials of soybean cake milk and formula feed. The method of making soybean cake milk is to use 1 jin of dried bean cake for every ten thousand fish fry, soak it for 4 hours for 5 hours, and then grind it with 4 parts of water and 1 part of bean cake. When feeding, choose one side of the shallow pool, on the slope of the pool around the 30cm under the water, feed in a small pile with an interval of 2 meters and 2 jin per pile. It is called "du Tan" method, and it is cast once every morning. In the afternoon, 10 jin of Piaosha (Wuping) was applied with mixed compost per mu per day, the fertilizer of visible water increased or decreased, and the particle size of formula feed was controlled at 0.5~1.0mm.

2) add fresh water: once a week, add fresh water 10~20cm deep, 10-15 days later, grass carp summer flower has reached 7~9cm, then enter the second stage of feeding, that is, fixed culture.

2. In the second feeding stage, summer flowers are bred into winter or spring slices of 6 inch (20~25cm), with 0.4 ~ 6000 summer flower fry per mu with full length 7~9cm per mu. During this period, mixed culture was adopted, with a larger pond area of 6 to 10 mu and a water depth of 1.8 to 2.5 meters.

1) main body fish rearing: grass carp summer flower fingerling with body length 7~9cm has been able to swallow pellet bait. It can be raised by mainly raising grass carp, silver crucian carp, silver carp and bighead carp.

2) feeding and management: grass carp summer flower under the pool, the second day with 1.5 mm particles of bait sprinkled, adopt five operating methods:

Fixed person: specially appointed person to manage. One person manages 3-5 ponds, covering an area of about 30-40 mu.

Timing: the feeding times are determined according to the temperature change, and the feeding times are more when the temperature is high. The water temperature is 15 ℃, twice a day at 20: 24 ℃, three times a day at 25: 28 ℃, and four times a day at an interval of 3 hours above 28 ℃.

Fixed point: bait machine mechanical feeding.

Quality: the bait should be fresh and the crude protein content is 30%. The content of crude protein in diet was 28% in the later stage of growth.

Quantitative: the daily feeding rate is determined according to the change of temperature.

Body length 8~12cm is the post-feeding stage, feeding should be both green feed and concentrate, and the daily feeding rate of compound feed is 710%.

In the body length 12~14cm stage, the particle size 2.5mm compound feed was mainly fed with water and dry grass, and the daily feeding rate of the compound feed was 30.6%.

3) diligent observation, prevention of floating head, prevention of fish disease: fish breeding stage, sooner or later to patrol the pond. In order to prevent the pool water from anoxia caused by weather changes, new water should be injected frequently, or the aerator should be turned on to adjust the water quality.

Weather changes affect the growth and feeding of mackerel species, and feeding should increase or decrease food intake according to the change of weather. If the temperature is low in the morning and there is less dissolved oxygen in the water, the amount of food should be reduced, and the sunny noon weather should be fed more. Don't overeat in the evening. When the dissolved oxygen in the water is less than 3 mg / L, the fish will not gain weight by eating the food.

4) Pond water disinfection and feeding bait: from June to September, the pond water was disinfected once every half a month, and the commonly used drugs and their dosage were as follows: bleaching powder 1 mg / L (1.3-1.5 jin / mu); mixture of copper sulfate and ferrous sulfate 0.70 mg / L (0.9 jin / mu); trichlorfon 0.50 mg / L (0.6 jin / mu); quicklime 20 mg / L (20kg 25 jin / mu); the above drugs were used alternately.

Drug bait can be given once every semimonthly, each time for 3 days, adding 50 grams of oxytetracycline to every 100 jin of feed, or selecting sulfonamides, furans and other drugs as bait for discretionary feeding.

Fish fry and fish fry transportation

In the process of transporting grass carp fry and fry, no matter what method is used, the operation must be meticulous, pay attention to the following aspects:

1, the fry is physically strong, the fry room is inflated (long waist point), the mouthparts are open, swimming is lively, and it can be shipped. The amount of oxygenated transport in nylon bags is about 80% of that of the transport box.

2. The water quality is fresh and non-toxic and the dissolved oxygen content is high. The water of rivers, lakes, reservoirs and ponds can be used, and the water with colorless transparency and low mud content should be selected. Tap water should be dechlorinated and stored for 24 hours before use. Use cold water in summer.

3. Before the fingerling is transported, the fish should be trained by pulling the net to remove feces. The body is strong, reduce mucus secretion, in order to improve the survival rate.

4, pay attention to the temperature balance, the temperature difference should not be ±2 ℃, after arriving at the destination, you should first wake up the fish in the box, and feed the fish fry with cooked egg yolk an hour later. 100000 fish fry are fed with one egg yolk. After seeing the fish fry sausage (swallowing the egg yolk into the intestine), wait another hour before putting the fish into the pond. For the fish fry in nylon bags and transport boxes, put them into the water before leaving the box to make the internal and external water temperature consistent. Then open the nylon bag or transport box, pour water into the pond, put the bag into the box, and let the fry (fry) swim out on their own.