How to breed carp
ⅱ Breeding
1. Selection and breeding of parent carps
1. Selection criteria: good body shape, strong mobility without injury, ratio of body length to body height The ratio is 3:1, which is typical of the variety. The female fish should be at least 2 winter years old and weigh 1.5kg, and the male fish should be at least 2 winter years old and weigh more than 1kg. Carp in the first sexual maturity and aging stages have poor egg quantity and egg quality, so they are not suitable as broodstock.
2. Gender identification
Non-reproductive season: Female fish have wide body, high back, small head, larger and soft abdomen, small and wide pectoral and pelvic fins, flat or slightly cloaca. Protruding, with radiating folds; the male fish has a long and narrow body, a larger head, a small and hard abdomen, large and long pectoral and ventral fins, anus slightly concave inward, and no parallel wrinkles.
Reproductive season: The abdomen of the female fish is soft and sac-shaped, the anus and genital pore are larger, slightly red and protruding; the abdomen of the male fish is smaller, and the gill cover, chest and pelvic fins have obvious secondary sexual characteristics." "Chasing Stars", the anus and genital pores are concave, not red or swollen, and milky white semen flows out when the abdomen is gently pressed.
3. Feeding and management
(1) Feeding: The broodstock breeding pond is 1-2 acres, the water depth is about 1.2 meters, sheltered from the wind and sunny, easy to fill and drain, and put 150-200kg per acre. During artificial breeding, the males and females should be separated to prevent them from mating and laying eggs on their own. Use quick lime or bleaching powder to disinfect before placing.
(2) Management: Strengthen the breeding of parent carps, and feed high-protein feeds such as bean cakes, silkworm pupae, and fish meal. In recent years, some manufacturers have developed broodstock feed, which is rich in ve and other vitamins, can promote development and improve anti-stress ability, and has good effects. At the same time, during the feeding process, attention should be paid to adjusting the water quality, frequently adding fresh water, and maintaining micro-flowing water to stimulate gonad development.
2. Induction of labor and hatching
1. Timing of induction of labor: When the water temperature rises and stabilizes above 16°C, labor can be induced. Usually during the Qingming Festival to Guyu period, after the cold wave, when the temperature rises and stabilizes, labor can be induced.
2. Methods of inducing labor
(1) Natural spawning is a very common method because of its small investment and scale.
a Spawning pond: an area of 0.5-1 acres, a water depth of 1.2 meters, and a pond with convenient drainage. Fish can be released one week after disinfecting with quicklime.
bArtificial fish nest: used to adhere fish eggs. Choose materials with soft texture, good toughness, non-toxic and non-perishable materials, such as pine branches, palm flakes, polyethylene sheets (woven bags), poplar roots, etc. They must be cleaned, tied and disinfected before use (0.3‰ formaldehyde or malachite green). Straw is not suitable for fish nests because it is perishable.
c Hatchery pond: It can also be used as a fry breeding pond. It should be a small area (1-2 acres), a sterilized pond with little silt and a water depth of 1 meter. Both the inlet and outlet need to be filtered with encrypted mesh to prevent impurities from entering the pool and fish fry from escaping.
d Pool spawning: Merge 35-30 groups of mature brood carp into the pool according to the male to female ratio of 1:1-1.5, and slowly add new water. At the same time, stretch 1-8 thin wires on the water surface, and hang artificial fish nests on the wires (or break bamboo in two and sandwich it in the middle and place it on the water surface). Usually each group of broodstock should be equipped with 4-6 fish nests.
e Management: Eggs are usually laid between 22:00-9:00 and last for 2-3 days. Therefore, the fish nests should be checked and cleaned every afternoon, and the fish nests with eggs attached should be moved into the hatching pool. Add new fish nests. If spawning is not good after merging the pond, the water level can be lowered to let the sun shine. You can also add more ve to the feed, or use micro-flow water to stimulate it. In order to ensure the uniformity of the fry, the eggs on the same day should be hatched together. This can also prevent the eggs from sticking into lumps and increasing the number of blind eggs.
(2) Artificial induction of labor: more common in fish breeding farms
a Injection of oxytocin: Artificial chorionic gonadotropin (hcg) 600-1000iu or inducing hormone per kg of female fish 30-50 micrograms of lutein-releasing hormone analogue (lrh-a), or a reduced dose and mixed use, and the dose for male fish is halved. Generally, at 6 pm on a sunny day, a predetermined dose is injected into the chest cavity at the base of the pectoral fin, and then moved into the spawning pool, and fresh water is added for half an hour. The water temperature is 18°C and eggs can be produced after 6-15 hours (the higher the water temperature, the better) The shorter the effect time, the opposite is true).
b Spawning and fertilization: The broodstock after induced labor can lay eggs on their own in the pool, the method is the same as (1). If artificial eggs are collected, the fish can be picked up before the climax of estrus, wipe the water from the fish body with a towel, squeeze the eggs into a dry porcelain basin, quickly squeeze in the semen, stir it with feathers to allow it to be fully fertilized, and then fertilize it The eggs are evenly spread on the fish nest and placed in the hatching tank for hatching. Or use talcum powder solution to debond and then incubate in running water. When the water temperature is 16-22℃, seedlings can emerge in 3-5 days.
3 Management:
(1) Natural hatching: 300,000-500,000 fertilized eggs are placed in each acre of pond. Eggs from the same day should be put in together to ensure that the fry are neatly sized. . Special attention should be paid to preventing saprolegnia. You can use 0.3‰ formaldehyde or malachite green to soak fish nests with eggs in them in advance. (2) Debonding hatching: The key is to adjust the water flow rate so that the fish eggs do not sink but are suspended in the water. At the same time, prevent sand windows from being blocked. When the fry hatch, slightly reduce the flow rate to prevent the water from flowing too fast and consuming the fry's physical strength.
Improving the hatchability rate is the key to artificial reproduction. The main reasons that affect the hatchability rate are sudden changes in weather during the spawning period, poor water quality, low dissolved oxygen, fish eggs being parasitized by mold, etc. We should try to prevent the harm.
ⅲSeed cultivation
Cultivation of summer flowers and fish fingerlings.
1. Summer flower cultivation
1 Pond preparation: Choose 1-2 acres, water depth 0.8-1.2 meters, little silt, east-west fish pond, clean and disinfect according to conventional methods.
2 Fertilization (also known as fertilization in the pond): 7-10 days before the fry are put into the pond, fermented manure can be applied, such as 150-300kg/acre of pig and cow manure (about 5 picks). You can also apply 5-10kg/acre of inorganic fertilizers (chemical fertilizers, phosphate fertilizers, etc.), and perform quicklime disinfection at the same time (150kg/acre). One week later, the fry will enter the pond at the peak of rotifers. The fry will have sufficient palatable food and will grow vigorously.
3. Release the fry: Before releasing the fry, use a dense mesh to empty the net to remove wild impurities. You can also release 50-80 cheap silver carp seedlings to test the water. After proving that everything is safe, you can release them. Fish, 100,000-250,000 fish/acre.
4 Clear water in the pond: Put the fry directly into the pond without applying base fertilizer. This method has less palatable feed rotifers in the water and is not enough to eat, so the fry are weak and have a low survival rate.
5 Management:
(1) Timely feeding: After the fry enter the pond, they grow very fast in the first few days, and there is often a shortage of natural bait, so pay attention to feeding. It is commonly used to mix soybeans with cooked egg yolks into a pulp and pour them into the feed. Grind 2-4kg of soybeans and 3-5 cooked egg yolks per acre into a slurry every day and pour them immediately for feeding, focusing on the water surface a few meters near the edge of the pond. You can also pour filtered fresh pig blood every three days. Some of the soy milk can be directly eaten by the seedlings, or it can fertilize the water and enrich the natural bait. Currently, there are also fry feeds circulating on the market, which are shaped like microcapsules or powder and can be fed from 6 to 8 minutes. It can not only supplement food, but also induce the fry to grab food, thereby promoting the development of the digestive tract and helping to increase the survival rate. and strong seedlings.
(2) Top dressing and water management: Apply top dressing every three days to keep rotifers in the water at a high level. You can also pump part of the water from the fatter adult fish pond every day and add it to the fry pond, which can not only increase the natural bait for the fry, but also prevent the occurrence of air bubble disease caused by excessive water in the adding machine well. The water should be changed 1/3-1/2 every week.
(3) Careful observation: Inspections should be strengthened during the fry cultivation process. Observe its activities, feeding, growth, changes in water quality, and whether there are predators, diseases, etc. At the same time, the fry should be divided into pools at a timely manner to prevent uneven sizes caused by overcrowding. If necessary, it is necessary to pull the net to exercise the fry and enhance their endurance.
Cultivation of two-standard fish species: After cultivating with summer flowers, the body length and weight of the fry have increased many times, and their adaptability has also been greatly enhanced. The changes in their feeding habits have become characteristic of the species, and they have begun to like concentrates, so they should be Make a smooth transition to compound feed as early as possible. The feeding methods are:
1 Monoculture method: Choose 2-4 acres, water depth 1-1.5 acres, sterilized pond, release 3000-6000 summer croakers/acre, and feed compound feed Or a mixture of bean cakes, silkworm chrysalises, and fish meal, which requires more than 35% feed protein, 8-12 times a day, and a feeding rate of 5-8%.
2 Polyculture method: Polyculture carp summer flower with other fish species, carp can be the main one or supplemented. If carp is the main species, the feed should be strengthened. If silver carp is the main species, the water quality can be properly cultivated. If grass carp is the main species, the carp should be released less.
3 Feeding and management
(1) The earlier the fry open for food, the earlier they start to grow and the better they will grow. We should strive to make a smooth transition to feeding with full-price compound feed as soon as possible.
(2) Pay close attention to the early stage of the flourishing fish species (especially within the 25-30-inch period), which grow very fast, increase in body length and weight quickly, and require more feed. At this time Feeding should be strengthened, and some fishermen’s feeding rate exceeds 10% during this period.
(3) Feeding adheres to the "four fixed" of fixed quality, timing, positioning and quantification, and feeds according to the feeding rhythm of fish species.
(4) In daily management, do "three inspections and four inspections" in the morning, noon and evening to understand the climate, fish situation and illness, and maintain the rapid growth of fish. At the same time, regular water injection and flood prevention and prevention are also required. Skip work.
ⅳAdult fish farming
Carp is widely distributed and has many farming methods, such as ponds, cages, running water, fences, rice fields, mountain ponds and other farming methods, which are introduced here For pond culture, please refer to relevant books for other culture methods.
1. Carp-based farming model
The size of the fish pond is not limited, but the bait coefficient will be higher in large ponds, and the water depth is 1.2-1.5 meters. Carp of different sizes can also be The seeds are put in in batches to facilitate catching and releasing.
This model mainly feeds compound feed, with more than 30% crude protein, 4-6 times/day, and a feeding rate of 3-8%. Its management points include the traditional "water, seed, etc." In addition to the eight-character essence of ", bait, density, mixing, wheeling, prevention, and management", there is also a new "cross" policy: excellent seeds, refined materials, good water, and meticulous management. Although the first six characters of the new "cross" policy are similar to the experience of the old "eight characters", the new era should include new content, either strengthening or supplementing. The emphasis here is on fine management, which requires the breeding and management personnel not to neglect any link.
Even if it is a penny of investment, the output must be calculated. Only in this way can high efficiency be guaranteed.