What kind of feed are generally fed to cultured carp, and how to control the amount of feed? What is the breeding density? What are the artificial breeding techniques?

Freshwater fish species carp, alias carp crutch, carp, hair, red fish. Origin of Asia, after the introduction of Europe, North America and other regions, omnivorous. What kind of feed are generally fed to farmed carp, and how to control the amount of feed? What is the breeding density? What are the artificial breeding techniques?

What kind of feed are generally fed to cultured carp, and how to control the amount of feed?

Carp's favorite feed formula:

1. Wheat bran 45%, bean cake 40%, barley 10%, fish meal 5%, adding multivitamin, inorganic salt, lysine, methionine, feed coefficient is 2.

two。 Wheat bran 45%, fish meal 30%, bean cake 15%, barley 10%, the amount of additive is the same (1), the feed coefficient is 2.

3. Bean cake 50%, fish meal 15%, wheat bran 15%, rice bran 15%, multivitamin 1%, inorganic salt, antibiotic leftovers 1%, adhesive 2%, bait coefficient 2.7.

4. According to the actual situation, scientific choice and scientific feeding can bring higher breeding benefits. At present, the mainstream culture mode is large mixed culture and rotation, and it is difficult for farmers to accurately estimate the weight of fish in their ponds. It is easy to control the feeding rate according to the feeding situation of the farmed objects, which can easily lead to high feeding rate.

Such a management method in a certain period of time the growth rate of breeding objects is too fast, leading to the decline of fish immunity, a variety of fish diseases followed, on the one hand, resulting in feed waste, resulting in water quality corruption, rising breeding costs; serious may lose all their money.

What is the density of carp culture?

Generally speaking, it is better to cultivate carp about 3000 jin per mu of pond, with about 300 jin of other fish, too much is prone to disease, and the cost of breeding increases sharply. Generally speaking, grass, silver carp and bighead carp are mixed! Now let's see that the highest density of the four major domestic fish in Henan has reached 10,000 jin! Generally speaking, 1 mu of Tangzi mixed culture to 2000 kg 3000 jin! Of course, there is also a big gap among regions, climate, environment, water quality, aquaculture technology and investment.

What are the artificial breeding techniques of cultured carp?

1. Daily feeding mode

The size of the fish pond is unlimited, and the water depth should be 1.2 to 1.5 meters, but the bait coefficient of the large pond will be on the high side, and carp species of different sizes can be put in stages and batches to facilitate rotation. Daily management should do a good job of "three rounds and four checks" in the morning, in the middle and in the evening, grasp the climate, fish situation and disease, maintain the rapid growth of fish, and at the same time regularly inject water to do a good job in flood control and escape prevention.

In addition to following the eight-character policy of "water, seed, bait, density, mixing, wheel, prevention and management", feeding should also meet the standards of "excellent seed, fine feed, good water and fine management". Feeding should adhere to the "four-fixed" principles of quality, timing, positioning and quantity, and be fed according to the feeding rhythm of fish species. Carp like to live in the lower layer of water, and the optimum water temperature for growth is 25 ℃ ~ 32 ℃. The growth of carp slows down significantly above 32 ℃ or below 15 ℃, and stops feeding below 10 ℃. The appropriate amount of dissolved oxygen is more than 4.5 mg per liter, eat less if less than 2 mg, stop eating 1 mg and float your head. Pay close attention to the early feeding of Wang fish fry, especially within 30 days from inch slices to 25 inches, so the growth period is particularly fast, and the body length and weight increase rapidly, and the feeding rate of some farmers in this period is more than 10%. The earlier the fry opening, the earlier the starting point, the better. It should be smoothly transferred to full-price formula feed as soon as possible, requiring more than 30% crude protein, 4 times per day, and the feeding rate is 3% 8%.

two。 Breeding and selection of parent fish

Parent fish cultivation pond 1 mu, water depth of about 1.2 meters, shelter from the wind to the sun, convenient injection and drainage, disinfection with raw lime or bleach before stocking. It is 150 kilograms per mu and 200 kilograms per mu. In order to prevent self-mating and spawning, male and female should be separated during artificial reproduction. Carp are generally sexually mature at the second age, and some individuals can also mature at the first age. The spawning season varies with the region, spawning in batches, spawning from March to August, and the peak period is from April to June. Most of the spawning grounds are in the shallow lake bay or river bay where there is a lot of water and grass, and the eggs are very sticky and firmly adhere to the water plants after spawning. the number of eggs varies with age and individual size, ranging from 15 to 800000 eggs. The eggs can be hatched after 4 to 6 days at the water temperature of 15 ℃ ~ 20 ℃.

The number and quality of eggs in the first sexual maturity and aging period of common carp are poor and should not be used as parent fish. The optional ratio of good body length to body height is 3:1, and the active and harmless adult fish is the parent fish. The female fish is at least 2 winter years old and weighs 1.5 kg, while the male fish is at least 2 winter years old and 1 kg or more. In the non-reproductive season, the female fish has a wide body, high back, small head, large and soft abdomen, small and round thoracic and ventral fins, flattened or slightly protruding cloaca, radiation folded; males have a narrow body, a large head, a small and hard abdomen, large and sharp fins, and a slightly concave anus without parallel wrinkles. In reproductive season, the abdomen of female fish is soft and saccular, the anus and reproductive foramen are larger, slightly reddish and prominent; the abdomen of male fish is smaller, the operculum, chest and ventral fin have obvious accessory sexual characteristics, the anus and reproductive foramen are concave, not red and swollen, milky white semen is discharged from the abdomen under light pressure.

3. Spawning and breeding management

There are two ways to induce spawning: natural spawning and artificial spawning. Carp usually lay eggs from 22:00 to 9:00 the next day, lasting 2 to 3 days, 30: 35 can be made up of mature parent carp 1 ∶ 1 / 2 and pool according to male and female and slowly add new water, draw 8 fine iron wire on the surface of the water, and hang artificial fish nest on the wire (or clip it in the middle and put it in the water with bamboo one broken into two), usually each group of parent fish should be equipped with 4 fish nests. Check and clean the nests every afternoon, move the nests with eggs into the incubator and replenish the new nests. If spawning after the pool is not good, the water level can be lowered to let the sun shine, and more vitamin E can be added to the feed, or stimulated by micro-running water. In order to ensure the uniformity of fish fry, the eggs on the same day should be hatched together, which can also prevent the number of blind eggs from increasing due to the agglomeration of fish eggs.

Artificial spawning is more common in fish farms. Per kilogram of female fish, artificial chorionic villi are used to promote gonadotropin 600-1000 ml or yellow-releasing hormone analogue 30-50 micrograms, or it is reduced by a mixture, and the dose of male fish is halved. It is usually injected into the chest cavity at 18:00 in the afternoon according to the predetermined dose at the base of the pectoral fin, then moved into the spawning pool, and injected with fresh water for half an hour, the water temperature is 18 ℃ and lasts for 6-15 hours, then oestrus can be laid. Note that the higher the water temperature, the shorter the effect time, and vice versa.

After spawning, the parent fish can lay eggs on their own in the pond, which is the same as the natural spawning type. If the artificial egg collection can be picked up before the most exciting part of the fish estrus, wipe off the moisture of the fish body with a towel, squeeze the eggs into the dry porcelain basin, quickly squeeze into the semen, stir with feathers, let them be fully fertilized, and then evenly smear the fertilized eggs on the fish nest and put them in the incubator to hatch. Or the seedlings can be hatched in running water after debonding with talcum powder solution, and the seedlings can emerge in 3-5 days when the water temperature is 16 ℃ ~ 22 ℃.

Naturally hatch 30 to 500000 fertilized eggs per mu of pond, and the eggs on the same day should be put together to ensure the neat specifications of fish fry. Special attention should be paid to preventing water mildew. Fish nests with eggs can be washed in advance with 0.3 ‰ formaldehyde or malachite green.

Debonding and hatching should timely adjust the flow velocity so that the fish eggs are suspended in the water without sinking, and at the same time prevent the screen window from clogging. The flow rate of fish fry is slightly reduced when it is hatched to prevent the physical exertion of fish fry caused by excessive current.

Sudden change of weather during spawning period, poor water quality, low dissolved oxygen, parasitism of fish eggs by mold and other reasons will affect the hatching rate. Efforts should be made to prevent its harm and improve the hatching rate to ensure the efficiency of culture.

4. Strengthen epidemic prevention

Furunculosis is most common in mixed fish ponds dominated by silver carp, which has no typical season and can occur all the year round. The skin and muscle tissue of the back of the diseased fish are inflamed, and then fester into abscess, and the hands feel puffy. Abscess around inflammation, congestion, fin erosion into a brush (also known as broom fin), severe intestinal bleeding inflammation. Fish species, water bodies and ponds should be thoroughly disinfected; take ciprofloxacin 80 mg per kilogram of feed internally, and disinfect the water body with 1 international unit of bleach per mu for 3 days.

The body surface of the diseased fish is rough, and some of the scales (mostly in the back of the fish) open outward like a pine ball, so it is called pine ball disease; the scale sac accumulates translucent or bloody exudate, so that the scale is erect, also known as scale disease. Put a little pressure on the scale with your fingers, and the exudate will spray out from under the scale, and the scale will fall off. Red ulcers, exophthalmos and abdominal swelling were formed at the desquamation, and died 2-3 days later. There are two epidemic periods of the disease, one is the spawning period of carp, the other is the overwintering period of carp, the mortality rate is 45%, and the highest is 85%. Be careful when pulling the net to prevent fish from getting hurt. Disinfect fish, water quality and ponds. 50-80 mg of oxytetracycline or chlortetracycline can be added per kilogram of feed to make erbium.

Cyprinid uterine nematode disease, also known as red nematode disease, often harms adult carp. In winter, the worm body parasites under the scale, but the worm body is small and does not show disease. When the water temperature warms up in spring, the growth of the worm body accelerates and causes fish disease. The diseased fish scales are loose, and the muscles around the scales are congested, inflamed and ulcerated, which can easily lead to water mildew. The parasitic scales show a red-purple irregular pattern, and the red body can be seen by lifting the scales. Quicklime can be used to strictly disinfect and kill larvae. Scrub the affected area with iodine or 1% potassium permanganate, or rinse with 2% salt water for 10 minutes.