Lecture 46 The "Eight-Character Intensive Cultivation Method" of spotted forked catfish

Spotted forktail catfish meat is delicious and nutritious, especially without intermuscular spines, easy to process, and the export situation is relatively good. Using the basic principle of the "Eight Character Intensive Culture Method", on the basis of highlighting the "water, species and bait" in the breeding process of spotted forktail catfish, the "dense, mixed and round" is used as a healthy breeding means, the strength of "prevention and management" is strengthened, and the relevant standards are strictly implemented in the breeding process to ensure that the farmed fish meet the export requirements and achieve the purpose of high yield and high efficiency.

　　"Water". Catfish breeding bases must be concentrated and contiguous, no industrial and agricultural pollutants around them, and the production environment indicators comply with the provisions of GB/T18407.4-2001. The water source is sufficient, the inlet and drainage is convenient, and the water quality meets the NY5051-2001 standard. The area of the fishing pond is about 6670 square meters (10 acres), and the water depth is 1.8 meters to 2.5 meters. The bottom of the pond is flat, sandy soil or loam soil, keeping a thick bottom mud of 5 cm to 6 cm. In the process of breeding, once a day in the morning and evening, the pond is inspected once a day, the change of water color and water level, the activity and feeding of fish are observed, the water quality index is measured regularly, the new water is injected in a timely manner, and the quicklime or compound microbial agent is regularly sprinkled to ensure that the dissolved oxygen of the pond water is 3.5 mg /l ~ 7 mg / l, the pH value is 6.8 ~ 8.5, and the transparency is 30 cm ~ 35 cm.

　　Species. Fish fingerlings are best self-bred, and the production qualifications of the seed farm must be checked before purchasing fry, and the qualified inspection and quarantine department shall issue a test report. Purchased fingerlings must be produced in pollution-free bases and quarantined and disinfected. Catfish species are required to swim actively, have a strong physique, smooth body surface, rich mucus, no injury, no disease, no deformity, and a size of about 50 g/tail. Stocking should be carried out in February to March, and the fish body should be bathed in a 2.5% to 3% salt solution for 5 minutes before descending the pond.

　　"Bait". To select a special compound feed with large scale and stable quality, the feed factory must be registered by the commodity inspection department, and the feed quality meets the NY5072-2002 standard. The types and amounts of additives used in feed comply with GB13078 standards. The bait should be fed evenly, fully and well, and must not be fed spoiled feed. Feeding twice a day, the daily bait rate is adjusted according to the water temperature, the general water temperature of 8 °C ~ 15 °C is 1% ~ 1.5%, 15 ° C ~ 20 ° C is 2% ~ 2.5%, 20 ° C ~ 25 ° C is 3% ~ 3.5%, 25 ° C ~ 32 ° C is 4% ~ 4.5%. Among them, 60% of the total amount is invested at 9:00 a.m. and 40% of the total amount is cast at 3:00 p.m.

　　"Secret". From the perspective of healthy breeding, the stocking of catfish fingerlings should be in the range of 12,000 fish/100 square meters to 15,000 fish/100 square meters. Excessive stocking densities can lead to management difficulties, deteriorating water quality and difficulty in withstanding adverse factors caused by weather changes that exceed the capacity of ponds.

　　Mixed. Spotted forktail catfish are mainly monoculture, but a small number of silver carp and bighead carp species can be appropriately mixed. Generally, 10 days after the stocking of catfish species, 100 grams/ tail silver carp and 3000 bighead carp fingerlings are mixed into 3000 fish / 100 square meters to 6000 / 100 square meters.

　　Wheel. After 2 to 3 years of rearing, the ponds where catfish are reared are changed to other aquatic products, which is also an important measure to prevent the outbreak of fish diseases.

　　"Defense". Adhere to the principle of "comprehensive prevention and active treatment". Adopt integrated ecological control and use of biological agents and Chinese herbal medicines to control diseases, and promote healthy breeding techniques. The use of fishing drugs must comply with the NY5071-2002 and NY5072-2002 standards.

　　Fish species should try to avoid mechanical damage, long-distance transportation or dry ponds, transfer ponds should be soaked in salt water to prevent the occurrence of skin diseases. Green drugs such as allicin are often added to the feed to prevent intestinal diseases, and are regularly sprinkled with quicklime with a concentration of 15 mg/L to 25 mg/L, or chlorine dioxide disinfectant from 0.3 mg/L to 0.5 mg/L to prevent fish diseases and regulate water quality. Fish diseases are detected, correctly diagnosed, and treated in a timely manner. The use of fishing drugs should be particularly cautious, and must be prescribed by qualified personnel, and avoid unauthorized use of drugs, otherwise the sale of commercial fish will be "vetoed".

　　Tube. In addition to production management, the focus should be on: (1) environmental management. Focus on monitoring the factors that may cause pollution in the base and surrounding areas, and eliminate domestic sewage, farmland water and "three wastes" pollution. At the same time, the relevant departments are entrusted to conduct sampling tests on soil, atmosphere and water quality on a regular basis. (2) Medication management. In accordance with the provisions of the Regulations on the Administration of Veterinary Drugs, fishery drug supervisors are appointed to establish a drug prescription system. (3) File management. The cleaning of ponds, the stocking of seedlings, the status of water quality, the use of feed and fishing drugs are required to be recorded in detail, and it is clear that special personnel will regularly inspect and file them.