Practical tips for saving feed in yellow catfish farming

Currently, yellow catfish (Pelteobagrus fulvidraco) farming is quite widespread, and it is a major farmed species through which fisher-farmers in many places increase their income. However, during the farming process, many farmers, in their one-sided pursuit of output, do not know how to save feed and continuously put excessive feed and fertilizer into the farming water body, which not only drives up farming costs day by day but also causes the water quality to deteriorate continuously, affecting the growth of yellow catfish and resulting in low farming returns. How can feed costs be saved in production practice?

Strictly remove trash, clear the pond and disinfect. Clearing and disinfecting the pond can both kill wild trash fish and reduce competitors for food, and also kill disease-causing agents in the water body and improve water quality, giving yellow catfish a good environment for feeding and growth. If there are many wild trash fish and miscellaneous shrimp in the pond, they will compete with yellow catfish for bait, and ferocious fish may even prey on yellow catfish, reducing feed utilization, so care should be taken to remove them.

Before stocking fry, both new and old ponds must be cleaned and disinfected. Old ponds should have excess silt removed, keeping only 10 cm of bottom mud. 10 to 15 days before stocking @#@233@#@, disinfect the pond with chemicals to kill pathogens and harmful organisms in the farming water body. Generally, two methods can be used: dry pond disinfection or disinfection with water in the pond. For dry pond disinfection, about 75 kg of quicklime per mu or 4 kg to 5 kg of bleaching powder can be used; for disinfection with water in the pond, about 150 kg of quicklime per mu can be spread over the whole pond, and the bottom soil should be mixed with the quicklime as much as possible, so as to thoroughly kill parasites, pathogens and wild trash fish, reduce competitors for food, and improve feed utilization. Pond farming of yellow catfish requires relatively deep water, abundant water sources, good water quality, and the ability to drain and irrigate, so ponds of 2 mu to 5 mu should be chosen, requiring a stable and sufficient unpolluted water source, and the water quality must meet aquaculture water standards. The pond should have convenient inlet and drainage, and a flat bottom, and be able to guarantee a water depth of 1.5 m to 2 m, because if the water is not deep enough and the light is too strong, it is unsuitable for the yellow catfish's habit of feeding under weak light. Before stocking fingerlings, sufficient base fertilizer should be applied. Generally, fermented organic manure is used to fertilize the water, at 150 kg to 200 kg per mu, and the fingerlings are stocked after large numbers of zooplankton appear in the pond water.

Pay attention to rational stocking. A reasonable stocking density can improve feed utilization; suitable matching species can make full use of feed, coexist mutualistically, achieve harmony in the water body, and improve feed use efficiency. To achieve a high survival rate in yellow catfish farming and reduce feed waste, stocking density and companion fish species must be well controlled. When stocking fingerlings, large-sized fingerlings of about 30 g each should be selected for grow-out rearing. The stocking quantity of fingerlings can be flexibly controlled according to pond conditions, management level, feed supply and fingerling size, and the stocking density should be as appropriate as possible: too sparse means low pond utilization and low returns, while too dense means slow fish growth and induced disease; matching should be reasonable, on the premise of fully using the water layer space of the pond and avoiding competition for food. Generally, about 1,500 yellow catfish fingerlings of 30 g each can be stocked per mu, and about 200 silver carp and bighead carp of 50 g each can also be matched. The stocked fingerlings should be uniform in size, bright in color, smooth in body surface, free of disease and injury, with intact fins and strong physique, and should be soaked in 5% salt water for 10 minutes before entering the pond. Yellow catfish fingerlings are generally stocked in late April each year, and the matched silver carp and bighead carp should be stocked half a month after the yellow catfish enter the pond, so as to benefit the growth of yellow catfish. In addition, as the fish continue to grow, in order to regulate the farming density and improve returns, they can be harvested in batches for market and subjected to rotational harvesting and stocking, so as to regulate the fish-carrying capacity in the water body and improve the feed conversion return.

Scientific fertilization and feeding. The amount of farming inputs such as fertilizer and bait affects both the growth of yellow catfish and changes in water quality. In natural waters, the food of yellow catfish is mainly small shrimp, fish and fish eggs, and some aquatic insects and aquatic plants, so artificial farming can use fresh live animal bait such as small fish and shrimp, and scraps from livestock and poultry processing, and can also feed soybean cake, peanut cake, bran, etc. Generally, self-made compound bait is mostly used for domestication feeding. The bait is made by mixing imported 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 35% to 45%, and the crude fat content is 5% to 8%; in the later stage, small trash fish meal can replace part of the imported fish meal, and a protein content of 30% and fat of about 6% is sufficient. The reference formula is: fish meal 25%, soybean cake 20%, rapeseed cake 30%, @#@245@#@ meal 20%, corn meal 3%, minerals 2%, vitamins 0.2%. The bait fed must be fresh, free of mold and spoilage, and it is advisable to choose complete compound feed produced by reputable manufacturers. In feeding, pay attention to grasping the principles of "domestication feeding, early start of feeding, and small meals more often." Wild yellow catfish like to feed by hiding by day and coming out at night; under artificial farming conditions, after 5 to 7 days of domestication, they can completely come to the bait station to feed during the day. Two days after the fry and fingerlings enter the pond, artificial feeding domestication is adopted, and during domestication a fixed feeding signal is used to carry out fixed-point and fixed-time feeding training. After patient domestication for 5 to 7 days, they can feed normally; with fingerlings domesticated in this way, normal feeding can begin on the second day after entering the pond, and feeding methods can take two forms: manual and mechanical feeding. When feeding, feed should be started early and small meals should be given more often. The whole feeding process should be divided into three stages. In the first stage, in May and June, feed 4 times a day, with a daily feeding rate of 3% to 5%; in the second stage, from July to September, feed 3 times a day, with a feeding rate of 2% to 3%; in the third stage, after October, feed 2 times a day, with a feeding rate of 2%, feeding during the period each day when dissolved oxygen is relatively high. On this basis, the feeding amount should also be adjusted according to weather and water quality conditions. In addition, because the yellow catfish has a relatively large mouth opening, the bait particle size should be correspondingly increased, using 2 mm particle feed as the opening feed, and the particle size of adult fish feed can reach more than 5 mm. Sinking hard pellet bait is required to remain stable in water for 15 minutes; using floating bait will better improve bait utilization.

Regularly regulate water quality. To farm fish, first cultivate water; the quality of the water affects the speed of yellow catfish growth and the feed coefficient. Yellow catfish like fresh water quality; when water quality is good, they grow quickly, have fewer diseases, can make full use of bait, and the feed coefficient is reduced. In grow-out farming of yellow catfish, water quality management is the most critical, and a clean water environment needs to be maintained. To prevent the water body from aging, in May and June inject water once a month, each time replacing with 30 cm of new water, and from June to September change the water once every half month, each time changing about 15 cm, keeping the water depth at 1.2 m to 1.5 m. Persist in regular disinfection; from June to September, use 15 ppm quicklime to spread over the whole pond once a month, to purify and disinfect the water quality and reduce excessive organic suspended matter in the water. Every half month, use 5 kg of quicklime (or 2 kg of bleaching powder) for local treatment once at the feeding ground and the aerator. Persist in observing the water body's algal phase and algae concentration, and according to the water color use inorganic fertilizer (urea, superphosphate, potassium dihydrogen phosphate, etc.) to regulate the water's fertility, keeping transparency at 30 cm to 35 cm. Scientifically use the aerator according to dissolved oxygen measurements and weather and water quality conditions; on sunny days, persist in running it for 1 hour in the early morning and in the afternoon, and in rainy, stuffy and hot weather make full use of mechanical aeration to supplement the insufficient dissolved oxygen in the water body; dissolved oxygen should be maintained above 3 mg/L.