Techniques of culturing herring in pollution-free ponds

Herring, also known as herring, snail green, black turtle, steel green, is one of the four major domestic fish in China, belonging to the subfamily Cyprinidae. The figure is cylindrical, the tail is flat, the abdomen is round; the back and the upper half of the body are bluish black, the abdomen is milky white, and each fin is grayish black. It is a benthic carnivorous fish. juvenile fish mainly feed on zooplankton, chironomid larvae and nauplii, and like to eat snails, clams, small fish, shrimps and aquatic insects at the adult stage. Under the condition of artificial culture, all kinds of compound feed can be fed.

Herring is large, thick, fatty, delicious, less intermuscular thorns and rich in nutrition. It contains 19.5 grams of protein and 5.2 grams of fat per 100 grams of meat, as well as a lot of vitamins and zinc. It is the top grade of freshwater fish. it has the best meat quality and high economic value among the four domestic fish. Herring pollution-free culture has broad prospects for development. 1. The aquaculture environment requires that the aquaculture environment includes atmospheric environment, water environment for fish growth and water quality of fishery sources, etc., and the aquaculture environment must comply with the provisions of the national standard "Environmental requirements for the safety and quality of agricultural products and pollution-free aquatic products producing areas" (GB/T184074-2001), "Fisheries Water quality Standard" (GB/T11607-89), and "pollution-free food freshwater culture water quality" (NY5051-2001). 1. The water area of herring culture should be selected in the waters where the ecological environment is good, the water source is abundant, and there is no or no direct pollution by industrial "three wastes" and agricultural, urban life and medical wastes. There are no pollution sources that pose a threat to the aquaculture water environment in the aquaculture waters and upstream of upwind and irrigation water sources. two。 The removal of excess silt from the pond is composed of biological corpses, residual bait, faeces, all kinds of organic debris and various organic and soil sediments. Through the decomposition and ion exchange of bacteria, they continue to dissolve and release into the water, providing nutrients for the reproduction of food organisms. However, too much sludge will produce a large amount of hydrogen sulfide, methane, organic acids, lower amines and mercaptan, which accumulate in water and affect the health and growth of herring. Therefore, excess silt should be removed. The specific measure is to drain the pond water and remove too much silt every 2012, so that it is more appropriate to retain about 20 centimeters of silt at the bottom of the pond. At the same time let the bottom of the pool exposure and freezing, killing pests, parasites and disease-causing bacteria. 3. Disinfection of pond water body to improve pond environment, eliminate enemy pests, prevent some bacterial diseases, and disinfect ponds and water bodies. The commonly used disinfectants and their dosage are as follows: ① cleans the pond with quicklime water with a content of 200mg ~ 250mg per liter, or sprinkles the whole pool with quicklime water with a content of 20mg ~ 25mg per liter; ② cleans the pond with 20mg / L bleach with water, or sprinkles the whole pool with 1.0mg ~ 1.5mg bleach per liter ③ was disinfected with sodium dichloroisocyanurate solution of 0.3mg ~ 0.6mg per liter in the whole pool, or trichloroisocyanuric acid solution of 0.2mg ~ 0.5mg per liter. 4. Water quality management water environment is the basis for the life and growth of herring in the pond, and various fish culture measures also act on the fish through the environment. Therefore, water quality management is the "bridge" of pollution-free culture of herring. It is necessary to ensure that the pond water is rich in plankton, organic matter and nutrients, and the transparency of the pond water should be kept between 25 cm and 40 cm. The dissolved oxygen in the water is more than 4 mg, the pH value is 7-8.5, and the water quality meets the requirements of "fertilizer, live, tender and cool". 2. Cultivation of fingerling production and introduction of herring fingerling should comply with the provisions of the Fisheries Law of China, the quality Standard of Black Carp fry (GB9956-88) and the measures for the Management of Aquatic fingerling issued by the Ministry of Agriculture. The parents used for breeding must come from the original improved breeding farm, and the quality should meet the standard of parent carp, grass carp, silver carp and bighead carp (GB/T5055-1997). The production conditions and facilities shall meet the requirements of the production technical operation rules, and the quality of the seedlings shall be inspected and quarantined by qualified professional and technical personnel. 1. The pros and cons of the selection of herring fingerling can be distinguished according to the size of the size of the pond, body color, the activity of the fry and the physical strength: the high-quality herring fry should meet the "quality standard of herring fry", with neat specifications, bright color, shiny, lively action, diving into the bottom quickly after being frightened, and strong ability to grab food. During the sampling inspection, the seedlings jumped wildly in the white porcelain basin, the body was fat, the fins were intact, and there was no abnormal phenomenon. On the contrary, it is inferior seedling. two。 The cultivation of seedlings can be divided into two stages according to the different feed requirements of herring seedlings at different development stages. ① fry stage. The spray with plastic film for 3 ~ 5 days, the stocking density is 1 million ~ 1.5 million per hectare, and the pond area is 1334 ~ 2668 square meters. Soybean milk was fed from the first day to the 10th day after entering the pond, 30 kg per hectare in the first 5 days, 40 kg per hectare in the last 5 days, and increased twice a day after 10 days. Add 15 cm ~ 20 cm of water every 5 ~ 7 days, and add 1.3 m ~ 1.5 m water depth to summer flowers. According to the water quality of the cultivation pond, appropriate amount of topdressing should be applied. After about 25 days of cultivation, the fry should be sparsely divided into ponds, and two or three intensive exercises should be carried out before leaving the pond. ② fingerling stage. Eating habits gradually diverged and began to eat small snails. The stocking time is before the Summer Solstice, the suitable area is 2000 ~ 4000 square meters, the water depth is 1.5m ~ 2m, herring is 80 ~ 100000 per hectare, bighead carp is 18000 ~ 20, 000 per hectare, crucian carp is 5000 per hectare. First, lure the herring to the table with a small amount of concentrate, then feed soybean cake milk twice a day, 23 kilograms per ten thousand tails; mix vegetable cakes after 5 centimeters, and soak vegetable cakes or bean cakes after 7 centimeters; mix crushed snail clams after 10 centimeters, starting with 30 kilograms per ten thousand, and then gradually increase. "four determinations" should be carried out in baiting. Fixed point: feeding at the table or food farm; timing: twice a day, 8: 00 a.m. to 9: 00 a.m. and 2: 00 p.m. to 3 p.m. Quality: high-quality fresh bait is given according to different growth stages. Ration: each feeding shall be finished within 1.5 hours. The proportion of monthly feeding to the total feeding amount is 4% in June, 15% in July, 23% in August, 25% in September, 15% in October, 10% in November, 4% in December and 4% from January to March. The food farm is often cleaned, disinfected and kept clean. Often inject water, control the amount of fertilizer moderately, sufficient dissolved oxygen. Patrol the pond twice every morning and evening, carefully observe, arrange production according to the situation, find the disease and treat it in time. Third, adult fish culture 1. Pond conditions Pond requires adequate water source, no pollution, water depth of 1.5m ~ 2.5m, area of 3335 square meters ~ 6667 square meters, solid ridge, no leakage, sufficient sunshine, flat bottom and less silt. Remove too much silt from the pond before stocking, freeze and sun for several days, add 30 cm of water, then sprinkle the whole pond with 150 kg of quicklime for every 667 square meters, filter and inject water every two or three days. Every 667 square meters soak 50 kg of tea seed cake for one day and night, then sprinkle. At the same time, it is required to have a power supply, which is equipped with a 3-kilowatt impeller aerator and a bait machine for every 2000 square meters to 3335 square meters of water. two。 When the toxicity of disinfectant disinfectant disappears, filter and inject water to prevent wild fish from mixing into the pond. Fish species should be released around the end of February, so the water temperature is low, the scales of fish are tight, and the fish species are not easy to be injured in operation such as net pulling and handling. Every 667 square meters, 200 ~ 250 two-year-old green fish with a tail weight of 1 kg, 100 silver carp fingerling, 50 bighead carp fingerling and 20 snakehead fingerling with a tail weight of 0.3 kg were released. Before entering the pond, the fish were bathed with a mixture of copper sulfate (8 grams per square meter) and bleach (1 gram per square meter) for 20 to 30 minutes, or disinfected with 3%-5% salt water for 15 minutes. 3. Feeding and management of ① feed selection. Feed should comply with the regulations on the Administration of Feed and Feed Additives, the Safety limit Standard for Fish compound Feed (NY5072-2002) and the industry standards for aquaculture. Carry out aquaculture in strict accordance with the "regulations on quality and Safety Management of Aquaculture" issued by the Ministry of Agriculture, and fill in the "Aquaculture production record" form. Feed requires consistent color, no peculiar smell, no mildew, deterioration, caking phenomenon, granular, smooth surface, high maturity. The feed should not be too loose, and the water stability should not collapse in 20 minutes. At the same time, the nutritional value of feed should be evaluated. The demand for nutritional value of feed is also different in different growth stages. The protein content is generally 35% 45% in the fry stage and 28% in 41% in the adult stage.

② feed. A feeding platform extending three or four meters to the center of the pool was built with wooden and bamboo boards, and the herring cluster was raised to grab food by domestication, and gradually gathered to the feeding table to feed at a fixed point with the bait feeding machine. The daily feeding rate can be 1.5% of fish body weight in March, 2.0% in April, 3.0% in May, 4.5% in June, 5.5% in July, 6.5% in August, 5.0% in September, 3.0% in October, 2.0% in November, and flexible control depending on water temperature, water quality, fish growth and feeding activities. Feed three or four times a day. Feed the fish 70 or 80% full each time. Feed evenly, and the duration of feeding should be controlled at 30 ~ 45 minutes.

Daily management of ③. Pond patrol: the pond must be inspected in the morning and evening every day to check the water quality and observe the fish situation. Oxygenation: from June to September, the aerator is turned on at noon in sunny days for one or two hours, and in the middle of the night on rainy days. When the floating head is heavy, it must be turned on until dawn. Water quality management: regular injection of new water, the water quality meets the requirements of "fertilizer, live, tender and cool". In June, quicklime is sprinkled in the whole pool every 15 ~ 20 days (15kg ~ 20kg per 667 square meters).

IV. Prevention and treatment of diseases the use of fishery drugs should comply with the national industry standards guidelines for the use of pollution-free Food and Fisheries drugs (NY5071-2002), the norms for the use of Feed Drug Additives and the list of Veterinary drugs and their compounds prohibited by Food and Animals. Carry out aquaculture in strict accordance with the "regulations on quality and Safety Management of Aquaculture" issued by the Ministry of Agriculture, and fill in the "Aquaculture Drug use record" form. 1. Prevention of fish disease at the end of April, early May and September to October, the whole pool of 90% crystal trichlorfon was sprinkled with 0.5 mg per liter to prevent and kill parasites such as Anchor head flea and Chinese flea. Two days later, the chlorine-containing preparations (bleach, dichloroisocyanuric acid, trichloroisocyanuric acid, chlorine dioxide and dibromohydantoin, etc.) were sprinkled in the whole pool to prevent secondary bacterial infection. From the middle of May to the end of August, quicklime and chlorine-containing preparation were sprinkled alternately in the whole pool from the middle of May to the end of August to prevent the occurrence of bacterial diseases such as enteritis and rotten gills. the content of quicklime was 20 mg ~ 30 mg per liter. two。 Drug treatment of herring fry, summer flower stage often parasitic rotifer, ring worm and other parasitic fish diseases; black carp larvae stage may occur horse racing disease; herring species are often infected with viral hemorrhagic disease; large-size herring species and one-and two-year-old adult fish are prone to bacterial enteritis, Gill rot and red skin disease. The fish was found to be sick and was diagnosed and treated immediately.