How to raise yellow catfish? All the key techniques are here

To farm yellow catfish well, the key work lies in doing a good job of pest and disease control for yellow catfish, and the following work should mainly be done well.

1. Do preparatory work in winter. Before stocking fry, both new and old ponds must be cleaned and disinfected. Old ponds should have excess silt removed, and it is enough to retain a 10 cm thick silt layer. Every winter, after the fingerlings are merged into ponds or the adult fish are harvested from the ponds, drain the pond water, clean up the sludge at the bottom of the pond and repair the pond embankments, and let the pond be exposed to the sun until it cracks. (1) Pond clearing. ① Dry pond clearing: first drain the pond water (or leave water 6-9 cm deep), and use 75-100 kg of quicklime per 667 sq m (1 mu), increasing or decreasing according to the amount of sludge at the bottom of the pond. When clearing the pond, first add water to the quicklime to make a milk of lime, and immediately sprinkle it evenly over the whole pond without waiting for it to cool. After pond clearing, the efficacy of the lime generally disappears after 7-10 days, and then fish can be released. ② Clearing the pond with water: when the water depth is about 1 m, use 125-150 kg of quicklime per 667 sq m for disinfection. The disinfection method is the same as the dry pond disinfection method, and its disinfection effect is better than the dry pond method. (2) Clearing the pond with bleaching powder. Generally, bleaching powder contains about 30% available chlorine, and its dosage is 15 kg per 667 sq m. First dissolve the bleaching powder in water, then sprinkle it over the whole pond. Generally, after 4-5 days the efficacy completely disappears, and then fish can be released.

2. Fry stocking. Large-sized fingerlings of about 30 g each should be stocked for adult fish rearing, with 1500 fish per 667 sq m, and 200 silver carp and bighead carp of 50 g each can be stocked together. The stocked fingerlings should be selected for uniform size, bright color, smooth body surface without injury, intact spines, and strong constitution. Before the fry enter the pond, they need to be soaked and washed in 5% salt water for 10 minutes. Yellow catfish fingerlings are generally stocked in late April each year, and the accompanying silver carp and bighead carp should be stocked half a month after the yellow catfish enter the pond.

3. Healthy feeding. (1) Feed preparation. In natural waters, the food of yellow catfish is mainly small shrimp, fish and fish eggs, and some aquatic insects, aquatic plants, etc. Therefore, artificial farming can use fresh live animal feed for rearing. Self-made compound feed can also be used for domestication feeding. The feed is made by combining fish meal, meat and bone meal, blood meal, soybean meal, rapeseed meal, dried fish worms, etc. with feed additives. In the early stage, the protein content is above 34% and the fat content is 4%; in the later stage, small miscellaneous fish meal can be used to replace part of the fish meal, with a protein content of 30% and a fat content of 6%. The feed fed must be fresh, free of mold, and free of sourness and spoilage. (2) Domestication. Two days after the fry enter the pond, artificial feeding is used for domestication. During domestication, a fixed feeding signal is used to train them to feed at fixed points and fixed times. After 5-7 days, they can feed normally. For domesticated fry stocked in this way, normal feeding can be carried out on the second day after entering the pond. The feeding method can use both manual and mechanical feeding. (3) Feeding amount. The whole feeding process should be divided into 3 stages. The 1st stage is May and June, with 4 feedings per day, and the daily feeding rate is 3%-5%. The 2nd stage is July, August, and September, with 3 feedings per day, and the feeding rate is 2%-3%. The 3rd stage is after October, with 2 feedings per day, and the feeding rate is 2%. In the 1st and 3rd stages, it is recommended to use the satiation method, that is, stop feeding after 90% of the fish on the feeding platform have left the platform. In the 2nd stage, because the weather is hot and water quality is prone to fluctuation, it is recommended to feed to 90% full, that is, stop feeding after 80% of the fish on the feeding platform have left the platform.

In addition, because the yellow catfish has a relatively large mouth opening, the feed particle size should be increased accordingly. Pellet feed with a particle size of 2 mm should be used as the opening feed, and the adult fish feed particle size should reach more than 5 mm. Sinking hard pellet feed is required to remain stable in water for 15 minutes, and using floating feed will better improve feed utilization.

Before the yellow catfish grows to 3 cm per fish, it mainly eats aquatic organisms. If aquatic organisms are insufficient, pure dried silkworm pupa powder can be used as a substitute. After the body length reaches 3 cm, it eats artificial compound feed. Two or more fixed feeding platforms suspended in the water can be set up at the corners of the stocking pond. The number of feeding platforms can be determined according to the size of the fish pond and the number of fish stocked. The feeding platform can be made of simple materials that can sink into the water, and the surface of the platform can be covered flat with soft materials such as woven bags. When feeding, add water to the powdered feed or pellet feed and knead it into small balls of 100-150 g, then put them on the platform and let the fish come onto the platform to eat by themselves. Feed once each in the morning and evening every day, and the amount of feed each time should be just about eaten up.

4. Water quality management. In adult yellow catfish farming, water quality management is the most critical. To prevent water aging, inject 30 cm of new water each month in May and June, and change 15 cm of water every half month from June to September, keeping the water depth at 1.2-1.5 m. From June to September, use quicklime water at a concentration of 15 mg/kg to splash the whole pond once a month. Every half month, use 5 kg of quicklime (or 2 kg of bleaching powder) for local treatment once at the feeding area and the aerator. Persist in observing the water body's algal phase and algal concentration, and use inorganic fertilizers (urea, superphosphate, potassium dihydrogen phosphate, etc.) to adjust the water fertility according to the water color, keeping transparency at 30-35 cm. Scientifically use the aerator according to the measurement of dissolved oxygen and the conditions of weather and water quality. On sunny days, insist on running the machine for 1 hour in the early morning and in the afternoon. In rainy and muggy weather, make full use of mechanical aeration to supplement the insufficient dissolved oxygen in the water body. The dissolved oxygen in the water body should be kept above 3 mg/L.

5. Disease control. When preventing and treating diseases, try to use high-efficiency, low-toxicity drugs, and determine the drug varieties to use by observing the therapeutic effect. (1) Insecticides. Splash the whole pond with a decis solution at a concentration of 0.03 mg/kg, which has a good effect on Dactylogyrus, Trichodina, etc. (2) Antibacterial and anti-inflammatory agents. For oral drugs (pressed into pellets and mixed evenly in the feed), mix 10 g of furazolidone with 20 g of oxytetracycline, add it to 50 kg of feed, and feed continuously for 3 days, twice a day. Oral penicillin capsules 5 g can also be used, added to the feed and fed continuously for 3 days, twice a day. For disinfecting the fish body, use a 0.25% bleaching powder solution or a diluted penicillin powder solution for concentrated soaking for 10 minutes. The above oral medicated feed is best prepared and fed immediately. Prepare once and feed for 3 days, and never leave it for a long time. It mainly targets diseased fish with bacterial infection. (3) Treatment of hemorrhagic disease. Use 50 kg of crude salt per 667 sq m and spread it over the whole pond. In treating yellow catfish diseases, the use of trichlorfon to kill insects should be refused, otherwise it will bring adverse consequences.

During stocking and transportation, try to avoid injuring the fish body, so as to prevent infection with water mold in early spring and in low-temperature seasons in autumn and winter. In high-temperature seasons, if hemorrhagic edema disease occurs, use nitrogen dioxide to splash the whole pond 2 times continuously, which can effectively treat it.