CATDOLL : CATDOLL: Artificial breeding technology of black carp

Recommended to you [Domestic News International News] [Artificial Breeding Technology of Black Carp] Artificial Breeding Technology of Black Carp 1. Parent fish breeding Parent fish should be over 6 years old and weigh more than 15 kg. They should be stocked at a male-female ratio of 1:1.5. About 10 black carps weighing 15-20 kg should be stocked per mu. The bottom of the parent fish pond should be flat, with sandy loam as the best. The water quality should be kept fresh. Snails, clams and mussel meat should be fed as the main food, supplemented with a small amount of bean cake and malt. New water should be added and flushed regularly. Generally, the water should be flushed once a month in winter and the water depth should be kept above 2 meters. After the beginning of spring, the water level should be lowered to increase the water temperature of the pond. The water should be flushed once a week. The number of flushings should be increased from mid-April to once every 2-3 days to promote the maturation of gonads. In the parent fish pond, a small amount of silver carp should be added to adjust the water quality. At the same time, carnivorous fish such as black carp and California bass can be appropriately raised to prey on wild fish in the pond, which is conducive to parent fish breeding and increases the efficiency of the pond. 2. Induced labor 1. Induced labor time and water temperature: In the middle and lower reaches of the Yangtze River, the inducing labor time is mid-to-late May, and the most suitable water temperature for inducing labor is 25~28. 2. Selection of broodstock: The maturity of broodstock directly affects the effect of inducing labor. The identification criteria are that the semen flows out of the abdomen of the male fish when it is lightly squeezed, and it immediately disperses after it meets water, and the abdomen of the female fish is swollen, soft and elastic, and the scales on the abdomen are sparse. In order to improve the maturity of the group, the net can be pulled in mid-April for inspection. For those with poor maturity, LRH-A 3~5 micrograms/tail can be injected according to the individual size and maturity of the poor maturity. 3. Injection of oxytocin: Commonly used oxytocins are LRH-A, DOM, PG, etc. Usually, the effect of mixing two kinds is better. Our farm uses three injections, and the inducing labor rate is high, up to more than 95%. The first injection is LRH-A1 microgram per kilogram per broodstock, and the injection interval is 20 hours; the second injection is LRH-A5 microgram per kilogram per broodstock, and the injection interval is 8 hours; the third injection is LTH-A20 micrograms per kilogram for female broodstock plus PG3~4 mg or DOM4~5 mg. The dose of male broodstock is 1/3~1/2 of the dose of female broodstock according to the specific situation. The injection is injected into the thorax. 3. The length of the effect time of estrus and artificial insemination varies with the water temperature. According to observation, the effect time is 6~7 hours when the water temperature is 26~28 degrees. When the broodstock is in estrus for the scheduled time and combined with the actual estrus situation, the broodstock is caught for artificial insemination. Pay attention to the light and fast movements during insemination. When the sperm and eggs are mixed, add 0.6% physiological saline appropriately to extend the insemination time. At the same time, avoid direct sunlight and rain splashing during insemination to improve the fertilization rate. The normal fertilization rate is more than 90%. 4. Hatching: Put the fertilized eggs after absorbing water into the hatching loop or hatching tank for hatching. The water flow rate should be enough to flush the fertilized eggs and roll them. The water for hatching should be separated into inlet and outlet, and should not be recycled. After the fry emerge from the membrane, the water flow should be increased appropriately to prevent the fry from sinking and suffocating to death. After the fish hatching for 24 hours, the water flow should be reduced appropriately to avoid excessive water flow consuming the fry's physical strength. The water flow rate during the same development period is less than that at night during the day. If the weather is abnormal and the temperature difference is large, the water flow should be reduced appropriately to avoid excessive water flow consuming the fry's physical strength. The water flow rate during the same development period is less than that at night during the day. If the weather is abnormal and the temperature difference is large, the water flow should be increased appropriately. 5. Disease prevention and control: Before each batch of hatching, the hatching pool should be thoroughly cleaned of dirt and disinfected with a certain concentration of mold net solution. Prevention should be the main focus, and prevention is more important than treatment. Before the fry emerge from the membrane, the water quality should be disinfected with mold net regularly to prevent and control water mold disease. After the fry emerge from the membrane, they are easily infected with wheelworm disease, which often causes large-scale death. Once the wheelworm pathogen is found, the hatching water should be immediately sprayed with 0.7 grams/cubic meter of copper sulfate and ferrous sulfate mixture until the pests and diseases are completely killed. 6. Pay close attention to daily management and improve the emergence rate. Establish and improve production and technical management systems, and strengthen administrative supervision and technical guidance. Make sure that a dedicated person is responsible for each production link, carry out drug disinfection according to the guidance of technical personnel, be proficient in adjusting water flow operations, wash frequently, and check for escape and leakage of seedlings. The normal emergence rate is over 75%. I hope you will adopt and give good comments.