Key points of grass carp green breeding technology management
With the increase of grass carp farming year by year, a series of problems have occurred in the farming, which cannot fully meet the higher level of market demand. The grass carp breeding area in Zhongshan is generally 50,000 to 60,000 mu per year. In order to explore new ways of green carp farming, the emerging aquatic product processing plant promotion station implemented a grass carp green farming technology research project in Zhongshan City, and actively explored a green carp farming model in Dacheng Town, Tancheng County. Through the implementation of grass carp green breeding technology projects, the ecological environment of ponds has been significantly improved, the incidence of grass carp has been significantly reduced, energy consumption and the use of fishery medicines have been greatly reduced, and the quality and safety level of aquatic products have been further improved. Improved the aquaculture technology level of Zhongshan City, promoted the enthusiasm of fishermen to develop fishery production, and strongly promoted the sustainable development of aquaculture and industry competitiveness in Zhongshan City.
Dongdian breeding farm in Dacheng Town, Tancheng County was selected as the test site for grass carp green breeding technology. The farm has an area of 140 acres, an area of 10 acres per pond, and a water depth of 1.5-2m.
2. Seed selection
2.1 Seed sources. Grass carp seed is sourced from Junchi Aquaculture Professional Cooperative of Yutai County, Jining City. Through field inspections, spot checks were carried out on seedlings, and healthy seedlings with good activity were selected.
2.2 Seed specifications. Grass carp seed specifications are 100 ~ 150g / tail. The size of the main fish is neat, and the individual difference in weight is within "10%". The size of the individual fish is generally not larger than the main fish.
2.3 Seed quality. Fingerlings require pure varieties, consistent sources, neat specifications, strong physique, and no injuries.
2.4 Disinfection. Before the seedlings enter the pond, all the seeds are soaked in salt water to disinfect the fish.
2.5 Vaccination. The main vaccine used for grass carp is the grass carp hemorrhagic disease live vaccine. 1,000 live vaccines were diluted with 200 mL of the dilution solution and used.
3. Technical measures for breeding
3.1 Stocking mode. Large-scale grass carp as the main fish stocking, 700 grass carp per acre; 300 catfish, 50g / tail; 100 catfish, 50g / tail; 500 catfish, 7g / tail; 100 carp, specifications 1g / tail.
3.2 Water quality management. The water quality is good, and it meets the standards of fishery aquaculture. According to the level of water and fertilizer in the pond, fertilization is reasonable. The color of the water is preferably yellow-green. Change the water once a day. Fish and vegetable symbiosis control, with vegetable water purification, fish long vegetables, and fish culture, appropriately increase the amount of filter-feeding fish and edible fish, improve the ecological structure of the pond, and achieve bioremediation. Use beneficial bacteria such as photosynthetic bacteria, Bacillus, nitrifying bacteria, etc. to achieve water purification; keep the pool water alive, refreshing and tender, with transparency above 35cm.
Fill with fresh water, and replenish it appropriately according to the evaporation of the pond water body. If necessary, fill with fresh water once every half a month; use environmental protection agents in a timely and appropriate amount. According to the bottom and water quality of the pond, Use 1-2 times a month, 20 ~ 30kg / mu of quicklime.
3.3 Use of substrate modifiers. The substrate modifier is mainly quicklime, which is disinfected when the substrate is cleaned. No other non-medicinal substrate modifiers were used in the test ponds.
3.4 Aeration mode. Use an aerator to increase oxygen. One aerator is set every 5 acres, and two aerators are set in the test pond. Reasonable use of aerator, open at noon on a sunny day, early in the morning on a cloudy day, open in the middle of the rain in the middle of the night, not open in the evening, the floating head opens early; The large load surface takes a long time to start up, the small load surface takes a long time to start, etc., to achieve its role of aeration, water agitation, aeration.
4. Disease prevention and control
4.1 Thoroughly clear the pond. Grass carp-main ponds must be cleared thoroughly before stocking to eliminate pathogens and enemy organisms. Drain the clear pond with quicklime and use 75kg per mu. Regular disinfection with chlorine dioxide or quicklime splashing throughout the pond, with emphasis on ponds and food counters. Regularly measure water quality indicators, monitor key indicators, and prevent and control any abnormalities in time. Keep ponds hygienic and prevent wild fish from entering the ponds.
4.2 Disinfection of fingerlings. Fish stocking must be disinfected. The fish can be immersed in a 3% to 4% saline solution for 15 minutes, or 10 mL / kg of bleaching powder, 8 mg / kg of copper sulfate, and other drugs can be immersed and disinfected.
4 .3 Feed disinfection. Green fodder is best sterilized with 5 ~ 10mL / kg bleach solution before feeding.
4.4 Chinese herbal medicine for disease prevention. In the production process, Chinese herbal medicine is used to prevent and cure fish diseases. Sanhuang powder is used to spray the feed evenly on the feed, and mixed with bait. The dosage is 200g of Chinese herbal medicine per 50kg of feed, which is continuously fed for 3 days to prevent fish disease every half month .
4.5 Disinfection of food courts. From June to September, the food court is disinfected once every 15 days. The method is to use 500g of bleaching powder to dissolve water around the food field after eating the fish, or sterilize by hanging bags or baskets.
4.6 Control feeding, grass carp greedy, as long as the environment is suitable, the appetite is basically uncontrolled. In high-temperature seasons, the food intake of grass carp should be restricted. Generally, it can be fed to 80% full, and grass carp cannot be eaten at night. Remove the remaining scraps every day.
4.7 Pool water disinfection. From May to September, the pool water is disinfected once every half a month, and the whole pool can be sprinkled with 20mg / L of quicklime.
5.1 Feeding method. Mainly feeding grass or a variety of aquatic plants, such as yarrow, reed, bitter grass, yarrow and so on. The amount of feed should be flexibly controlled according to the weather, fish eating conditions, and water quality. It is better to eat it every evening. In the hot summer season, grass carp should be strictly prohibited from eating night grass.
Do not change feed randomly during the breeding process to ensure the effectiveness of breeding. At around 4 pm every day, pelleted bait should be fed at 1.5% of the weight of the pond fish to supplement nutrition and domesticate concentrated feeding. Fish body
Recalculate, do not feed when the water temperature is high, feed 2 ~ 3 times / day when the water temperature is appropriate, and generally eat all in 1 ~ 2 hours. The use of grass carp feed and green feed is very effective. It can meet the needs of grass carp growth and save a lot of labor. At the same time, it is very good for purifying water and preventing fish diseases.
5.2 Feed management. The feed brand fed is Tongwei feed. The feed has good stability and palatability. The feed requires freshness, no deterioration, good physical properties, and stable nutrition. The uniformity of feed processing and the particle size of the feed ingredients meet the quality requirements of feed processing. . Purchase regular feeds or fishery medicines with complete documents, strictly follow the breeding regulations, and set up a special storage place according to the storage requirements to ensure ventilation and dryness.
6. Daily management
6.1 Seed quarantine
Purchased seedlings need a quarantine certificate issued by an official agency to ensure quarantine before the seedlings are released from the pond to prevent the occurrence of aquatic diseases.
6.2 Industry-University-Research Cooperation
The fishery is a scientific and technological demonstration site in Zhongshan City, and a county and county aquatic technology promotion agency. With grass-roots fishery technology promotion system construction as the starting point, combined with the city's modern fishery development projects, it will increase the promotion of aquatic technology, cultivate aquaculture technology masters, and improve aquaculture benefits.
6.3 Quality inspection
The farm is the designated unit for the provincial aquatic product quality inspection and the municipal aquatic product quality inspection. Every year, grass carp have 10 batches of test samples. Over the years, quality aquaculture inspections have not found aquaculture inputs and illegal fishery drugs to exceed standards.
6.4 Special monitoring
The project demonstration area is a routine monitoring point for fish disease forecasting in Tancheng County. The aquatic animal epidemic disease on the farm is monitored monthly, and a complete disease detection system is established to ensure the normal operation of the test pond.
6.5 Technical training
In combination with new-type fisherman training, key training is provided for technicians, and training is conducted once a year. County aquatic technical instructors go to the farm each week to provide technical guidance and solve problems in production in a timely manner.
7. Benefit analysis
Through the experimental demonstration and promotion of grass carp green breeding technology, it has reached the standards of high survival rate, fast growth rate, large size and good benefits of breeding objects. The breeding mode can be replicated and promoted. The survival rate of grass carp has been increased from 50% to Above 80%, comprehensive control of water quality through the use of new technologies such as aeration equipment and micro-ecological preparations has improved the breeding environment, increased the growth rate, reduced the feed factor, increased the yield per mu to 840 kg, and shortened the breeding cycle. The grass carp green breeding technology has been promoted and replicated in Tancheng County, and the area of popularized breeding has reached 30,000 mu, which has increased fisheries efficiency and increased fishermen's income.
With 700 grass carp per acre, the survival rate is above 80%. After 6 months of grass carp breeding, the seedlings grew to 1.5 kg / tail that year and the yield per mu reached 840 kg. The yield of other fish per mu is 377 kg, of which the yield of catfish is 170 kg per mu. The yield of catfish is 52kg per mu, the yield of catfish is 110kg per mu, and the yield of carp is 45kg per mu. The output value per mu is expected to reach 20,000 yuan. Seeds, feed, fertilizer, hydropower, depreciation of fixed assets, rent and staff wages per mu are totaled 12,000 yuan. The benefit per mu is 8,000 yuan. The total benefit of the test pond is 80,000 yuan.