How to effectively prevent grass carp diseases in autumn? Aquaculture tips shared
Aquaculture tips: How to effectively prevent grass carp diseases in autumn
(Agricultural Wealth Network) First, improve the disease resistance of fish through various means.
① Improve varieties: Use hybridization, especially crossing excellent grass carp from different water systems and selecting superior generations, to breed new varieties with strong disease resistance, fast growth, high survival rate, delicious meat, and good body shape.
② Promote artificial immunization techniques to improve the immune protection of fish.
③ Improve operation methods and eliminate parasites, snakes, rats, birds and other enemies to prevent fish from being scratched or bitten, protect the immune barrier of fish, and thereby improve fish immunity.
④ Implement scientific fish farming so that grass carp in good waters can eat well and eat enough, improving disease resistance, that is, adopting ecological disease prevention methods. First, reform the feeding system and methods for raising grass carp fingerlings, changing the practice of transferring fry once midway to transferring them 2 or more times, so that the water body and fry density are more reasonable, promoting fast growth and improving disease resistance; change dense culture to sparse culture. For fry stocking density, the first-level pond used to be 200,000 to 300,000 fish, and the second-level pond 20,000 to 30,000 fish; it is best to change this to 100,000 to 150,000 fish for the first-level pond, 10,000 to 15,000 fish for the second-level pond, and 3,000 to 5,000 fish for the third-level pond; change mixed culture of large and small fingerlings to sorting the coarse from the fine and raising them by category, preventing fingerlings from polarizing; in the late breeding stage (that is, third-level pond breeding), change fertilized-water breeding to lean-water breeding, because at this time the fingerlings have reached about 6 to 7 cm, their feeding habit has changed from mainly zooplankton to mainly green feed, and their natural habits have changed accordingly, so the third-level pond water does not need fertilizing or supplementary fertilizing. Second, do a good job of scientific feed formulation and adhere to the "four fixeds" feeding method to prevent nutritional deficiency. Grass carp fed compound feed should also be given an appropriate amount of green feed to supplement vitamins, so as to facilitate rapid growth of grass carp.
Second, do everything possible to eliminate pathogens and their vectors. Mainly adhere to the "two diligences": diligent pond inspection, diligent removal of pathogens and their vectors, and the "seven disinfections": water source disinfection, fish pond disinfection, manure disinfection, fingerling disinfection, feed disinfection, feeding ground disinfection, and tool disinfection.
Third, according to the requirements of each growth stage of grass carp, create an excellent environment to facilitate safe, healthy, and rapid growth of grass carp. In the early rearing stage (body length below 7 cm), grass carp fingerlings mainly feed on zooplankton and require water quality that is fertile and fresh (transparency 25 to 35 cm). In the middle and late stages, the feeding habit has completely transformed, mainly to green feed, and the water quality is required to be lively and fresh (transparency above 40 cm). Therefore, to make grass carp grow well, in the early stage the water quality must be reasonably fertilized (including base fertilizer and supplementary fertilizer) and appropriately algal, making the water fertile and fresh. In the middle and late stages, not only should fertilization not be carried out, but silver carp, bighead carp and other filter-feeding fish should also be reasonably mixed in to reduce fertilizer, and water should often be added to the pond or an aerator should be turned on to increase oxygen, making the water lively and fresh. In addition, the water quality is also required to be slightly alkaline (pH value 7.5 to 8.5).
① Improve varieties: Use hybridization, especially crossing excellent grass carp from different water systems and selecting superior generations, to breed new varieties with strong disease resistance, fast growth, high survival rate, delicious meat, and good body shape.
② Promote artificial immunization techniques to improve the immune protection of fish.
③ Improve operation methods and eliminate parasites, snakes, rats, birds and other enemies to prevent fish from being scratched or bitten, protect the immune barrier of fish, and thereby improve fish immunity.
④ Implement scientific fish farming so that grass carp in good waters can eat well and eat enough, improving disease resistance, that is, adopting ecological disease prevention methods. First, reform the feeding system and methods for raising grass carp fingerlings, changing the practice of transferring fry once midway to transferring them 2 or more times, so that the water body and fry density are more reasonable, promoting fast growth and improving disease resistance; change dense culture to sparse culture. For fry stocking density, the first-level pond used to be 200,000 to 300,000 fish, and the second-level pond 20,000 to 30,000 fish; it is best to change this to 100,000 to 150,000 fish for the first-level pond, 10,000 to 15,000 fish for the second-level pond, and 3,000 to 5,000 fish for the third-level pond; change mixed culture of large and small fingerlings to sorting the coarse from the fine and raising them by category, preventing fingerlings from polarizing; in the late breeding stage (that is, third-level pond breeding), change fertilized-water breeding to lean-water breeding, because at this time the fingerlings have reached about 6 to 7 cm, their feeding habit has changed from mainly zooplankton to mainly green feed, and their natural habits have changed accordingly, so the third-level pond water does not need fertilizing or supplementary fertilizing. Second, do a good job of scientific feed formulation and adhere to the "four fixeds" feeding method to prevent nutritional deficiency. Grass carp fed compound feed should also be given an appropriate amount of green feed to supplement vitamins, so as to facilitate rapid growth of grass carp.
Second, do everything possible to eliminate pathogens and their vectors. Mainly adhere to the "two diligences": diligent pond inspection, diligent removal of pathogens and their vectors, and the "seven disinfections": water source disinfection, fish pond disinfection, manure disinfection, fingerling disinfection, feed disinfection, feeding ground disinfection, and tool disinfection.
Third, according to the requirements of each growth stage of grass carp, create an excellent environment to facilitate safe, healthy, and rapid growth of grass carp. In the early rearing stage (body length below 7 cm), grass carp fingerlings mainly feed on zooplankton and require water quality that is fertile and fresh (transparency 25 to 35 cm). In the middle and late stages, the feeding habit has completely transformed, mainly to green feed, and the water quality is required to be lively and fresh (transparency above 40 cm). Therefore, to make grass carp grow well, in the early stage the water quality must be reasonably fertilized (including base fertilizer and supplementary fertilizer) and appropriately algal, making the water fertile and fresh. In the middle and late stages, not only should fertilization not be carried out, but silver carp, bighead carp and other filter-feeding fish should also be reasonably mixed in to reduce fertilizer, and water should often be added to the pond or an aerator should be turned on to increase oxygen, making the water lively and fresh. In addition, the water quality is also required to be slightly alkaline (pH value 7.5 to 8.5).