When to breed koi?
When is the time to breed koi? The following content is recommended to you:
Koi belongs to the carp family and is a large and valuable fish that is both ornamental and edible. It has a strong body, bright colors, brilliant markings and elegant swimming posture, which brings great beauty to people. It enjoys the reputation of "living gem in the water" and implies good luck, joy, prosperity and happiness. It is called "good luck fish" and "good luck fish". Feng Shui Fish”. Koi originated from China, and were bred and improved in Japan. After years of cross-breeding and breeding, Koi has now become a very unique carp. After Japanese koi was introduced to my country, it has developed greatly. And become a foreign exchange-earning product for export. At present, domestic and foreign markets are promising, and breeding is becoming more popular. The breeding technology is now introduced as follows:
1. Construction of fish ponds
The pond should choose humus soil, with a leeward and sunny terrain, and sufficient water sources (preferably spring water rich in mineral elements) , Build a pond in a place with convenient drainage and irrigation. Domestic koi can use the open space in the yard or the roof to build a pond. The broodstock pond area is 30-40 square meters, the pond depth is 1.5-2 meters, and the water depth is 1.2-1.5 meters. The spawning pool is 15-20 square meters, the pool depth is 1.5 meters, and the water depth is 1-1.2 meters. The hatching pool is 3-5 square meters, the pool depth is 0.8-1 meter, and the water depth is 0.6-0.8 meters. The seed pond is 10--15 square meters, the depth of the pond is 0.5--0.6 meters, and the water depth is 0.4 meters. The area of the adult fish pond depends on the amount of fish raised. The larger the area, the better. The pond depth is 1.5-2 meters and the water depth is about 1.5 meters. It is best to build a cement pool with the bottom layer sloping toward the drain end. Before using a new cement pool, remove alkali, add rice straw or wheat straw after filling the water, soak it for about 15 days, drain the pool water, and then rinse it with clean water several times. Then add new water for use.
2. Breeding and seed cultivation
The suitable breeding age of koi is generally between 3 and 10 years old, and the weight reaches more than 1.5 kilograms. Choose koi carp with strong physique, crystal clear color, obvious variety characteristics, steady swimming posture, and no disease or injury as broodstock. Around May every year, when the water temperature stabilizes above 16°C, male and female koi can be selected and put into the spawning pool in a ratio of 1:3. Disinfected fish nests are placed in the spawning pool in advance. After spawning, fish out the broodstock and transfer the eggs into the hatching tank. The fry will hatch after 5--7 days. The fry will start to float to the water surface to look for food 3-4 days after hatching. At this time, the fry should be fished out to the fry pond immediately. Use cooked egg yolk, soy milk, algae, soft worms, etc. as bait. After 1 week, feed water fleas, red worms, chopped earthworms, etc., and appropriately supplement artificial compound feed, and feed them once a day up and down. When the fish body grows to more than 2 cm, it can be moved to the adult fish pond and raised.
3. Feeding and management of adult fish
Koi have a large food intake, so it is better to keep the stocking density thinner. For large-area cement pond breeding, 3-5 fish per square meter is suitable, and mixed with grass, silver carp, bighead carp, etc. appropriately. Koi is an omnivorous fish. It can mix leftover rice, leftovers, fruit peels, etc. with about 10% of animal offal, snails, maggots, earthworms and other animal feeds to make pellets for feeding. The protein content of its feed should be about 35% and fat 5%--8%. The "four fixed" feeding should be adhered to, usually twice a day, once in the morning and once in the afternoon. The amount of feeding depends on water temperature, weather changes and fish feeding conditions. It is roughly 2%--10% of the fish's weight, and it is advisable to eat it within 20--10 minutes.
Insist on daily inspections and remove remaining bait residues in time. Change the water every 2-3 days in summer and every 4-5 days in spring and autumn. The water change amount is 1/ of the original pond. 3--1/2. Keep the water fresh. In hot and rainy weather, attention should be paid to adding oxygen to prevent flooding. In winter, koi can be moved indoors, and the indoor water temperature should be kept at 2-10°C. Appropriate feed should be easily digestible to ensure safe overwintering.
4. Disease prevention and control
Koi carp has strong vitality and is less likely to get sick, but it is necessary to do a good job in disinfecting the breeding pond and fish body. Quicklime, trichlorfon, etc. should be applied regularly, and affected fish should be diagnosed and treated promptly. The treatments for common diseases are as follows:
1. Enteritis. The sick fish have reduced appetite, move slowly, and often swim alone. The fish body turns black, the abdomen is enlarged, the anus is protruding, red and swollen, and yellow-red ascites flows out when the abdominal wall is squeezed. For prevention and treatment, 0.2 grams of sulfamiamidine per kilogram of bait can be mixed and fed to diseased fish for 5 consecutive days. For fish that are seriously ill and do not eat, kanamycin 500-1000 international units can be injected intraperitoneally for 3-5 days.
2. Saprolegniasis. The diseased fish has gray-white cotton-like mycelium parasitized on the body or fin rays.
Oral vitamin E, 0.4-0.6 grams per 10 kilograms of fish body weight per day, can enhance resistance. For sick fish, a mixture of 400-500 mg/L salt solution and 400-500 mg/L sodium bicarbonate solution can be used spray.
3. Vertical scale disease. The body surface of the sick fish is rough, the scales stand up, and the scale base is edematous. Prevention and treatment methods: ① Soak the fish body with 2% saline solution for 5-15 minutes, once a day for 3-5 days. ② Oral administration of sulfadiazine: First keep the diseased fish in 0.5% salt water, stop eating for 2 days, move them into clear water, feed 0.2 grams per fish, once every other day, and take it 5 times.
4. Small melonworm disease. There are white dot-like vesicles on the body surface, fin rays and gills of the sick fish. In severe cases, the skin and fin rays of the sick fish are covered with white dots and covered with white mucus. You can pour 10--15 mg/L formalin and 1--2 mg/L methylene blue into the whole pool, once every other day, and use it 2-3 times.
5. Ringworm disease. Ringworm parasitizes the body surface and gill filaments of fish, causing the gill valves to be swollen and grayish white. For prevention and control, crystalline trichlorfon solution with a concentration of 0.2--0.4 mg/L can be poured into the entire pond. You can also use potassium permanganate solution with a concentration of 0.2 mg/L to wash the fish body for 10-30 minutes.