Experiment on efficient ecological polyculture in freshwater ponds of Chinese turtles
_Wang Sufen
Chinese turtle muscle protein content is high, rich in trace elements, delicious taste, but also can increase human immunity, deeply loved by consumers. The author implemented the experiment of efficient ecological polyculture of Chinese turtle pond at Xinxiang Breeding Family Farm in Liangshui Town, Dongchangfu District, Liaocheng City, and achieved good economic benefits. The experience is summarized below.
1. Materials and methods
1. Pond conditions
The test site has a quiet environment, convenient transportation and good power conditions. There are 3 breeding ponds, a total of 25 acres, water depth of 1 to 2.5 meters, good water quality, convenient drainage and irrigation, and separate inlet and drainage facilities. The bottom of the pond does not leak, the water retention and fertilizer retention performance is better, and the depth of the sediment is maintained at 10 to 15 cm. In order to prevent the Chinese turtle from escaping, the inlet and drainage pipe holes are blocked with barbed wire, and an anti-escape wall of more than 50 cm is set up around the pond.
2. Preparation before stocking
(1) Clear the pond for disinfection. After the pond is repaired in the spring, the pond is cleared with bleaching powder 5 to 10 kg/mu 2 to 3 weeks before the seed stocking. First of all, the pond water is discharged to 5 to 10 cm, dig several small pits around the bottom of the pool, dissolve the bleaching powder in the pit and dissolve the water immediately after the whole pond is sprinkled, and then use an iron rake to rake the pond mud again, so that the silt and bleach powder are fully mixed; after the residual poison disappears (3 to 5 days), put water to wash the pool, drain it in 7 to 10 days, expose it to the sun for 5 to 7 days, and completely kill predators and fish parasites and pathogens.
(2) Build a bait table and an artificial turtle island. The bait table is made of cement slabs, 2 to 3 per acre, fixed around the turtle pond. The bait table exposes 30 cm above the water surface and has a certain slope, which is convenient for turtles to climb to feed. In order to create a good natural ecological environment, an artificial turtle island has been built in the pond, one is to facilitate the Chinese turtle to climb up to the sun and rest, and the other is to transplant aquatic plants such as water peanuts and water hyacinths around, and the total coverage area of aquatic plants accounts for about 40% of the water surface.
(3) Variety selection. Choose a juvenile turtle with neat specifications, no disability, strong physique, wide skirt, white belly with yellow, and yellow-green dorsal nails, with a specification of 300 to 500 grams per piece; select fish species with normal body shape, strong water traceability, complete scales and no diseases, with a specification of 200 to 300 g / tail, and soak and disinfect with 3% to 5% salt water before stocking, and the time is generally 5 to 20 minutes. Stocking takes place in mid-April, and the difference in water temperature before and after stocking must not exceed 3°C.
(4) Stocking quantity. The release of seedlings is carried out in good weather, and 300 to 500 young turtles and silver carp are released per mu, such as silver carp, filter feeding fish such as 100 to 200 fish, grass carp 80 to 100 fish, and in Addition, in March to April, 100 to 200 kg of live snails are stocked per mu, and 5 to 8 kg of egg-hugging green shrimp or baby shrimp are released to provide Chinese turtles with natural active bait that they like to eat. Stocking of seedlings is shown in Table 1.
Table 1 Stocking of seedlings
Second, cultivate management
1. Water quality control
Scientific control of water level, keep the water quality fresh, to regularly inject water, change water, so that the transparency of the pool water to maintain at about 30 cm. Control excessive growth of algae in time during the high temperature season to prevent the aging and death of aquatic plants. Regular sprinkling of quicklime 10 to 15 kg /mu for disinfection, sprinkling 1 to 2 times a month, also supplemented with the calcium needed for the healthy growth of Chinese turtles. When the pool water pH is high, do not use quicklime. In the middle and late stage of aquaculture, with the increase of pond load, especially the high temperature season consumes more oxygen, the aerator is reasonably opened to achieve "three open and two open" to prevent flooding. In July, as the amount of feeding increased, the water quality gradually became fatter, and the water quality was regulated using microbial agents. Bacillus subtilis and photosynthetic bacteria can be used interchangeably, with photosynthetic bacteria sprinkled once every 8 to 10 days and Bacillus subtilis sprinkled every 12 to 14 days. When the transparency of the water body is greater than 50 cm, fertilization should be carried out in time, a small number of times, usually every 8 to 10 days, to promote the reproduction of plankton and benthic organisms, improve the hidden habitat conditions of turtles, and reduce mutual biting.
2. Bait feeding
The amount of fish feed fed is 3% to 5% of the body weight of the fish in the eating pond, and it is advisable to eat in 1 to 2 hours. Feeding 2 to 3 times a day, feeding time is 9:00 a.m., 3-4:00 p.m. Snails and green shrimp provide natural high-protein bait for Chinese turtles, and at the same time, they should be fed a full-price compound feed with high protein and high calcium, the feeding amount is 8% of the weight of the pond turtle, and the evening feeding amount should account for 60% to 70% of the daily feeding amount; develop the habit of regular and fixed-point feeding of juvenile turtles, but Chinese turtles like to be active at night, and must be fed once a day in the evening. From April to May and October, it is fed 1 to 2 times a day; from June to September, the water temperature is suitable, and the digestion and absorption capacity of Chinese turtles is greatly enhanced, and it is fed 2 to 3 times a day to make it grow rapidly. The amount of feeding should be eaten 2 hours after feeding, but it should be flexibly grasped according to the weather, water temperature, water quality, feeding of Chinese turtles, and whether there is any disease.
3. Disease prevention and control
Adhere to the principle of "prevention first, treatment as a supplement, prevention is more important than treatment", and sprinkle the whole pool of quicklime with quicklime 10 to 15 kg/mu per month for disinfection, sterilization and water transfer. In the feed mixed with vitamins, minerals, photosynthetic bacteria, made into medicinal bait feeding, once a month, enhance the body's immunity, prevent diseases. In the process of breeding, rational use of drugs, scientific use of drugs, no abuse of drugs, priority in the use of Chinese herbal medicines and healthy, efficient, low-toxicity, no residue drugs to treat diseases, strictly control the amount of chemicals and the number of times of use, reduce the pollution of chemical drugs to water.
4. Daily management
Aquaculture inspection is an important daily work, generally every morning, middle and evening patrol pond, check the weather, water quality, fish turtle activities and anti-escape facilities whether damage, etc., especially at dawn when the water temperature is low, the oxygen content in the water is the least, check whether there are floating heads, sick fish, dead fish and other phenomena, find problems in time, do a good job of production records. At the same time, we must pay attention to disease prevention, strong wind prevention, and rainstorm escape turtles. In addition, according to the living habits of Chinese turtles, it is necessary to maintain a quiet surrounding environment, especially to reduce the number of nets in the pool to prevent the alarm of turtles.
Third, the efficiency of breeding
After two years of implementation, the experiment achieved good breeding results, and the harvest situation is shown in Table 2.
Table 2 Trial harvests
Turtle high-efficiency ecological polyculture pond catches a total of 8 087 kg of high-quality ecological commodity turtles with an output value of 646 960 yuan; silver carp 2 973 kg, with an output value of 32 703 yuan; bighead carp 2 955 kg, with an output value of 41 370 yuan; grass carp with an output value of 52 024 yuan; Chinese turtle with an average yield of 323 kg/mu and an average fish yield of 386 kg/mu. The total output reached 17,731 kg, with a total output value of 773,057 yuan and a unit output value of 30,922 yuan / mu. Costs of $434,300 ($147,050 for seedlings, $240,580 for feed, $25,000 for pond rent, $21,670 for others).
The total benefit was 338,757 yuan, and the average benefit per mu reached 13,550 yuan.
4. Analysis and discussion
1. Three-dimensional polyculture of multiple varieties in ponds
Using the different characteristics of different aquaculture animals such as habitat space, living habits and feeding habits, Chinese turtles are mainly based on benthic life, silver carp and grass carp live in the middle and upper layers of the water body, and carry out three-dimensional comprehensive polyculture in different water layers to maximize the use of space and bait resources. Chinese turtles breathe with their lungs and often move in the bottom and upper layers of the water, promoting the circulation of water and increasing the oxygen content of the water body. Chinese turtle bait and feces have high nitrogen, phosphorus and potassium content, which can cultivate fertilizer water quality, provide nutrients for plankton reproduction, and are used by filtered fish such as silver carp and transformed into fish products. The release of benthic animals such as snails in ponds can not only filter the organic matter of the bottom layer, improve the substrate and water quality, but also serve as a delicious live natural food for Chinese turtles. Chinese turtles do not harm healthy fish and can eat sick or dead fish, so polyculture of fish turtles and turtles can also play a role in preventing the spread of pathogens and reducing fish diseases.
2. Artificial turtle island was built to properly transplant aquatic plants
Artificial turtle island is convenient for Chinese turtles to climb out of the water in windy and sunny weather to "dry their backs". When "sunbathing" time, the sun ultraviolet rays can not only directly kill the chinese turtle surface pathogens, but also accelerate the blood circulation in the body, promote metabolism, and improve the body's disease resistance; the aquatic plants in the pond absorb organic matter and ammonia nitrogen, hydrogen sulfide, etc. in the water body, play a role in water purification, reduce the occurrence of Chinese turtle and fish and shrimp diseases, reduce drug input, and improve the quality of aquatic products; the aquatic plants planted also provide grass carp with tender vegetables, reduce the amount of grass carp feed feeding, and save breeding costs.
3. Reasonable use technology of microbial preparations
The microorganisms in the microecological preparation decompose the residual bait, excretion waste, animal and plant residues accumulated at the bottom of the pond aquaculture water body, as well as harmful substances such as ammonia nitrogen, nitrite and hydrogen sulfide into carbon dioxide, nitrate, sulfate, etc., to improve the dissolved oxygen in the water. The use of microecological agents every 15 days in ponds has played a significant role in improving the water quality of ponds, and the water color of the aquaculture ponds has become more tender, while reducing the incidence of fish and the emission of aquaculture water to a certain extent. The use of microecological agents can not only purify the water quality, but also provide nutrients for the reproduction of monocytoal algae, which is conducive to the reproduction and growth of algae, thereby promoting the growth of filter-feeding fish and increasing pond production.
4. Comprehensive ecological disease prevention technology
In the process of breeding, with the focus on ecological disease prevention (reasonable multi-species stocking mode, planting aquatic plants, reasonable feeding and special compound feed application, scientific application of microbial preparations, etc.), the disease prevention and control and the ecological environment protection of the water body of the breeding pond are organically combined to create an ecological environment conducive to the healthy growth of breeding animals, enhance the resistance of farmed animals, control the breeding and spread of pathogens, and control or reduce the occurrence of diseases.
In short, the efficient ecological polyculture mode of the freshwater pond of Chinese turtle maximizes the potential of the pond, makes full use of the material and energy in the ecological space of the water area and the aquatic ecosystem, significantly improves the aquaculture production, and greatly improves the aquaculture water environment, reduces the occurrence of diseases, reduces the emission of aquaculture water, and achieves the purpose of energy conservation and emission reduction, increased production and benefits.