The first is to adjust the structure of breeding varieties. In large-scale freshwater fish culture, it is an important means to scientifically adjust the proportion of mixed culture of edible fish (grass carp, herring, carp, bream, etc.). ) and fatty fish (silver carp, bighead carp, etc. ) in order to save the cultivation cost and improve the cultivation efficiency. There is a folk fishing proverb: "One grass brings three silver carp". In the past, when aquatic feed was cheap or aquatic plants were extremely abundant, fishermen would mix grass carp and silver carp at a ratio of 3: 1. Now, the price of aquatic feed has doubled. According to the bait coefficient of 1.8-2.0, it is basically useless except for labor and water rent. Based on the analysis of scientific fish culture theory and local production environment, we adjusted the polyculture ratio of grass carp and silver carp to 1: 1. On the basis of the original standard of releasing fry, the amount of grass carp decreased by 30%, while the amount of silver carp increased by 30%. Compared with before adjustment, the economic benefit has obvious advantages, mainly because there is demand for silver carp in the market in recent years. However, there are several points to be grasped in the stocking process: first, large-scale fish stocking, with specifications not less than 6-8 pieces/kg; Second, the aeration facilities should be matched, and the power of 10 mu aquaculture surface aerator should be above 2kw/ set; Third, comprehensive application of sufficient fertilizer, silver carp is a filter-feeding fish, mainly feeding on low-grade plant algae, and timely application of green manure and biological fertilizer can supplement the lack of manure and water of grass carp and other food-eating fish, and promote the normal reproduction of feed organisms; Fourth, according to the seasonal changes and the growth of fish, water should be replenished in time. As the saying goes, "a fish grows a minute, and the water is an inch deep." Generally, water injection is about 20 cm per week in summer and autumn, 10- 15cm per week in spring, with little or no water injection in winter.

Second, promote the cultivation of green fish in ponds. Planting herring is to make full use of solar energy, fish culture time, fish pond space and sediment fertility, and plant various green feed and green manure as feed or fertilizer for fish culture, so as to reduce production cost, increase the yield per unit area of pond and increase the economic benefits of aquaculture. During the greening period, some harmful microorganisms and parasites were inhibited and killed after exposure and freezing. The growth of plant roots also made the sludge at the bottom of the pond full of air, which promoted the mineralization and decomposition of organic matter in the sludge and improved the sediment. The basic model of seed culture is ryegrass (Chinese cabbage)-millet grass-Sudan grass-ryegrass (Chinese cabbage). Perennial ryegrass (Chinese cabbage) was planted in batches from late September to 65438+February, millet grass was planted on the platform at the bottom of the pond in March of the following year, and Sudanese grass was planted in early May to ensure that grass-eating fish such as grass carp basically had fresh grass all year round. The planting area of Lolium perenne (Chinese cabbage) in fish pond is generally about 10 mu (including ridge), and the planting parts are ridge and sloping land; The planting area of millet grass is 3 mu, and the planting part is the bottom of the pool; The planting area of Sudan grass is 2 mu, and the planting part is pond ridge. The yield of fresh grass in fish ponds with a general area of 10 mu is: 30 tons of Sudanese grass, 8 tons of millet grass, and 0/2 tons of ryegrass/kloc-0. The total output of fresh grass is about 50 tons. According to the average feed ratio of 40: 1, fresh grass can produce high-quality fish and grass carp 1300 kg, with an output value of10.5 million yuan. Save about 3 tons of compound feed, saving about 1000 yuan per mu.

Third, master scientific breeding skills. Making good use of feed feeding technology is directly related to the economic benefits of aquaculture. Many fishermen's friends only know what this aspect is and don't know why. Feeding technology is very important. First, we should follow the principle of "four determinations", that is, fixed points (the feeding platform should be selected in the flat middle of the pond bank, protruding 2-3 meters from the water surface, 40-50 cm above the water surface, too short and too high, which will blow the feed powder to the shore in case of wind, causing unnecessary waste) and timing (the feeding time is usually within 2 hours after the water surface is exposed to the sun or 2 hours before sunset). The daily feeding time should be relatively fixed), quantitative (the feeding amount is closely related to the weather, water temperature, fish condition and water quality. And under normal circumstances, "80% full" is enough), qualitative (feed should be "fine-coarse-fine", moldy, caked or smelly feed should not be fed, and green feed must be fresh); Second, feed evenly, and beat the bucket before feeding. As long as the fish are domesticated, they will swim to the feeding platform. When feeding, spread the feed as far as possible, so that each fish has sufficient opportunities to eat, and the feeding frequency should be moderate. If the fish swim too fast, the feed will sink to the bottom of the pool, causing waste. When it is too slow, the feeding time is too long each time, and the fish consumes too much physical strength to grab food, which affects feeding. Under normal circumstances, the duration of each feeding is controlled at about 30 minutes; Third, observe carefully, such as hot days, rainy days and low dissolved oxygen periods, and try to feed less or not to prevent flooding or waste of feed. When the bait feeder is turned on, someone should watch it to avoid the mechanical idling after feeding.

Fourth, the rational cultivation of economic fish. In order to make effective use of water space, in recent years, we have cultivated some famous and special economic fish in the process of cultivating a large number of freshwater fish, and the economic benefits are very considerable. If Siniperca chuatsi is interplanted, on the basis of not changing the number of grass carp, there will be about 100 large-sized Siniperca chuatsi fry over 7-8 cm per mu, and only the net income of Siniperca chuatsi per mu will exceed 1500 yuan. It is worth noting that in the case of sufficient bait, the variety and density of stocking should be reasonably matched; Under normal circumstances, the bait should be replenished in time. In addition, trichlorfon, pyrethroids and other drugs should not be used in ponds; Another mode is to breed soft-shelled turtles in sets, with 0.6-0.75 kg of soft-shelled turtles (males) 10 per mu, and let them grow naturally without feeding. Under normal circumstances, the average growth of soft-shelled turtles in that year was about 1.5 kg, and the net income per mu was 1.200 yuan. This mode is labor-saving and worry-free, which not only reduces diseases, but also increases income, but it is very important to prevent escape and theft. In addition, economic fish such as Pelteobagrus fulvidraco and black-tailed catfish can also be interplanted.

Five, the appropriate supplement of coarse grains such as wheat. In recent years, the prices of aquatic feed, cake and other products have skyrocketed, but our local area is rich in wheat, corn and other grains, but the prices are low, such as wheat 1900-2000 yuan/ton, which is half cheaper than ordinary aquatic feed. In this regard, we suggest that some fishermen engaged in large-scale freshwater fish farming can appropriately supplement wheat and corn. And also achieve the purpose of reducing costs. However, when wheat, corn, etc. are used. Pay attention to the following two points when feeding fish: First, limit the use. Crops such as wheat are only good energy feeds, and their crude protein content is only 10- 12%. If a large number of crops are fed separately, it is difficult to meet the demand of fish for protein, which is not conducive to the normal growth of fish. Second, soak it before feeding. Otherwise, it is difficult for fish to digest after eating, and it is bound to ferment in the digestive tract, resulting in the fish intestines being full of gas, the density dropping, floating on the water surface, and even dying in severe cases; The third is to advocate feeding fish after wheat germinates. This not only has rich nutrition and good palatability, but also can significantly improve the quality of fish. The cooked fish is tender, smooth, sweet and delicious. In addition, fish that eat wheat and corn are particularly resistant to transportation, which is another effective way to establish a distinctive brand.