How to cultivate silver carp in cage

Cage fish culture technology is a three-dimensional culture technology that makes full use of reservoir resources, which has the advantages of low culture cost and high benefit, and is deeply loved by the majority of fish farmers. Among them, the technology of cage culture of silver carp is the one with the highest profit among many culture projects.

How to cultivate silver carp in cage

First, do a good job in the cage structure. The material of the cage is polyethylene, the diameter of the wire is 1.13 mm, the size of the mesh is 3-5 cm, and the specification of the cage is 4 m × 7 m × 2 m. It is suitable to use single-layer cage, the frame is bamboo pole, the diameter of bamboo pole is about 10 cm, and several are connected into one. Use sunken son to fix the cage position so as not to be elegant.

Second, the position is placed. The shelving position of the cage is extremely important, which directly affects the growth rate of silver carp. It is generally required to be placed in the reservoir area with broad waters, micro-running water, good water quality, no pollution, sufficient sunshine, shelter from the wind and sun, high water temperature, sufficient bait organisms, near shore, water depth of 4-7 meters, less wind and convenient transportation.

Third, the scientific release of fish species. The best time for fish stocking is from November to December every year, or from February to March of the following year, with low water temperature, convenient transportation, less injury and high survival rate. The stocking specifications are about 80 grams or 350 grams respectively. Put 450-550 fish in a box for 80g fish fry and 200-250 fish in a box for 350g fish fry. The fish species put into the box should be strictly disinfected before and after entering the box to prevent the occurrence and death of water mildew. Before the fish is put into the box, because the fish is injured due to transportation and shipping, water mildew is very easy to occur in the case of low water temperature.

Fourth, careful management. The success or failure of cage culture of silver carp, feeding management is very important, good management, can accelerate the growth of silver carp, increase the yield and obtain better economic benefits. Otherwise, due to poor management, resulting in slow growth, high incidence, or even escape, breeding failure. Feeding management mainly includes the following aspects:

1. Bubble box. The surface of the new cage is rough, and direct loading of fish can easily cause damage to the surface of the fish body. Therefore, it must be soaked in the reservoir 7-10 days in advance to soften the net line.

2. Brush the box. When the cage is put into the reservoir, due to the action of plankton in the water, a lot of dirt is attached to the cage, which affects the exchange of water, resulting in a decrease in the number of plankton in the cage, so that silver carp grows slowly due to the shortage of food organisms. Therefore, the cage must be scrubbed frequently, usually in the growing season, once every 15-20 days.

3. Move. There are two cases of moving, one is to move the cage to prevent it from being washed out by the flood wind, and the other is to increase the content of bait organisms in the cage and accelerate the growth of silver carp.

4. Feeding. If the water body of the reservoir is thinner or there are more cages, other ways can not increase the bait organisms in the box, at this time, it is necessary to stack or hang organic fertilizer or chemical fertilizer around the cage, and the chemical fertilizer is hung in the absence of wind.

5. Separate boxes. After a year of culture, most of the fish species grow 10-20 times. In the following spring, in order to ensure the normal growth of the fish in the box and avoid the shortage of dissolved oxygen and bait in the box, the fish must be cultured in separate boxes to ensure the growth space.

6. Take care of. In the growing season, it is necessary to often check the cage, observe the activity of fish, find problems and take timely measures to prevent fish escape. In winter, unsold fish should be kept together to prevent the strong wind from breaking the cage or being stolen.

Fifth, appear on the market and sell. By the end of autumn, when the water temperature of the reservoir dropped to 10 ℃, silver carp had stopped growing and began to harvest and sell it. At this time, the input of 100g silver carp can grow to more than 500g, and each box can produce more than 200kg of silver carp; after dividing the boxes in the following year, it can grow to more than 1500 grams. Putting 350g silver carp can grow to 1000 grams, and each box can produce more than 250kg silver carp; after dividing the boxes in the next year, it can grow to more than 2500 grams, and the breeding benefit is very considerable.

Living habits of silver carp

1. Feeding habits: silver carp belongs to pelagic fish, which feeds on plankton all its life. It mainly eats zooplankton in the fry stage, and gradually changes to phytoplankton when it is more than 1.5 cm long, and likes to eat grass carp feces and chicken and cow dung. I am interested in sour food and have an appetite for bad food. Bait has obvious seasonality, in addition to plankton, but also eat a large number of sapropelic bait in Spring and Autumn. The lower the water level in summer, the greater its food intake, and it eats less and moves less in winter.

2. Water temperature: silver carp likes high temperature, and the most suitable water temperature is 2332 ℃. Silver carp have the strongest appetite in hot summer. Lively temperament, like to jump, have the habit of going against the current, but the action is not very agile, more clumsy. Silver carp like fertilizer and water, and individual imitators often gather and swim to the middle and upper layers of the water, especially in the open water area where the water quality is fatter. Timid fear of disturbance, the ability to withstand hypoxia is very poor, hypoxia in the water immediately floating head, some die soon.

3. Reproduction: silver carp has fast growth rate and high yield. The age of sexual maturity of silver carp is 1-2 years earlier than that of grass carp, and the mature individuals are also smaller. Generally, the female fish weighing more than 3 kg can reach maturity, and the relative number of eggs laid by the female fish about 5 kg is about 40-50 000 eggs / kg body weight. Under the condition of pond culture, if there is enough bait, the fish can grow to 500 kilograms in that year, the weight of three-year-old fish can reach 3 kilograms, and the weight of three-year-old fish can reach 30 kilograms in natural rivers.

Nutritional value of silver carp

Silver carp has sweet taste and warm nature, which can warm the stomach, tonify deficiency, resolve phlegm and relieve asthma. It is suitable for deficiency and cold of spleen and stomach, excessive phlegm, cough and other symptoms. People with weak constitution had better eat more fish head of silver carp, its warming effect is very good, and it can also play a role in treating tinnitus and dizziness. People with excessive phlegm and dizziness can cook with silver carp and tofu.

Bighead carp has a protective effect on cardiovascular system. Pituitrin, which is rich in phospholipids and improves memory, especially the brain pulp is very high. It can warm the stomach, dispel vertigo, benefit IQ, help memory, delay aging and moisturize the skin.

Culture techniques of silver carp

1. Selection and retention of parent fish: parent fish choose natural species, which requires good health and good gonadal development. The individual weight of silver carp is more than 6 kg, bighead carp more than 10 kg, herring more than 15 kg, grass carp more than 8 kg. The annual renewal rate of parent fish should be about 10%.

2, clean up the fish pond: the parent fish pond should be convenient for irrigation and drainage, silver carp and bighead carp pond bottom should have 20 cm deep silt, green carp and grass carp pond bottom should contain little or no silt. The area is 1 to 5 mu and the water depth is about 1.5 meters. The pond should be cleared before stocking.

3. Matching stocking: the female-to-male ratio of silver carp, bighead carp, green fish and grass parent fish is generally 1: 1: 1.5, and at the same time 810 mandarin fish and 150 tail silver carp are released per mu to control the breeding of wild miscellaneous fish and large zooplankton.

4. Feeding and management: before stocking, the parent ponds of silver carp and bighead carp should put 500,700 kilograms of mature organic fertilizer per mu to cultivate plankton, and proper fertilization should be applied in the future. In addition, soy cake milk should be fed in sunny and warm weather to promote gonadal development.

5. Early induction of labor: female fish can be induced to give birth with dilated abdomen and loose reproductive pores. Generally, female fish are injected with 1000 IU of oxytocin chorionic gonadotropin per kilogram of body weight, or LRH~A40~50 micrograms, and males are reduced by half.

6. Incubation management: the water for hatching should be filtered with a filter to prevent floating objects and wild miscellaneous fish from entering. Before each hatching, the incubator tank and incubator should be cleaned, the appropriate water flow should be provided during the incubation period, and the bottom corner of the water body should be turned frequently to check whether there are accumulated eggs and seedlings to maintain the water quality.

Silver carp culture is relatively common in China, and there are many techniques for silver carp culture, and cage culture is also one of the more commonly used methods, so farmers can communicate with each other and learn from each other's experience and technology. only in this way can we make the culture better.