Rainbow trout is a fierce cold-water fish, which has fast growth, strong disease resistance and adaptability. It can be cultured in water-flow ponds and cages, and cage culture is suitable for large-scale production, but should be used in rainbow trout cage culture. Pay attention to the following technical points: Children Face Mask,Kids Medical Disposable Face Mask,Kids 3 Ply Disposable Face Mask,Kids Nonwoven Disposable Face Mask KUTA TECHNOLOGY INDUSTRY CO.,LIMITED , https://www.kutasureblue.com
First, the choice of breeding waters
Rainbow Happiness likes to live in an environment with clear water, smooth water, and abundant water. It prefers counter-current and hi-dissolved oxygen. Therefore, when selecting the waters for cage culture, attention should be paid to adequate water supply, clear water, no pollution, and little change in water level. Annual water temperature varies from 4°C to 24°C on the open water surface of large and medium-sized reservoirs. The water quality meets the fishery water standards. The water flow rate is 10cm/s to 30cm/s. Proper control of water flow stimuli can cause normal movement of rainbow trout, thus enhancing food intake. With the acceleration of growth, the transparency of the water body is more than 2.0m, the higher the transparency of the water body under a condition, the lower the trophic level, the better the water quality, the better the production performance of cage fish, and the higher the potential fish production; The average annual minimum value is ≥6mg/L. When the dissolved oxygen is lower than 5mg/L, the rainbow trout's respiratory rate is accelerated and the patient feels unwell. Below 4mg/L, death will occur, normal growth above 6mg/L, and maximum growth rate of 9mg/L. .
Second, the cage structure and settings
1. The shape of the cage and the shape of the material cage are preferably rectangular. The rectangular cage is placed in the water body perpendicular to the direction of the water flow. The water body exchanges quickly and the exchange volume is large, which can ensure the fresh water flow required for rainbow trout breeding. The materials required to make cages are strong and durable enough to withstand the weight of the fish in the cage, do not hinder the exchange of water, resist corrosion, be light, and do not harm fish, and are reasonably priced. The size of the cages can be used to make cages of different specifications according to the requirements of different periods of rainbow trout farming. Because the daily management of cage culture rainbow trout is more complicated, in order to facilitate the operation and management, it is best to use a floating frame operation platform. The floating frame operation platform requires strong materials, durability, good buoyancy, wind resistance, easy operation, and easy maintenance. The frame platform consisting of steel and foam is reasonable and the most common. Hanging the box on the frame platform is a Independent breeding rainbow trout cages. The net cage is preferably made of nylon mesh sheet, which has the advantages of firmness and firmness, smaller pitch of the rope, small resistance when the water body is exchanged, corrosion resistance, light weight and easy abrasion of the fish body. The cage cover should completely cover the top of the cage and be movable. First, it can prevent the intrusion and predation of carnivorous fish and prevent natural enemies and thieves. Second, it can shield light and reduce the rainbow trout's stress response to light while reducing The exposure time of rainbow trout to sunlight helps to enhance the disease resistance of the rainbow trout's immune system, thereby improving production performance. Third, it reduces the entry of light and inhibits the growth of biofouling, and reduces the attachment of cage walls, which is beneficial to water bodies. exchange.
2. Set-up of cages Net cages should be installed in open waters to avoid narrow bays, lakes, and stagnant areas. They should also avoid areas where water flow is too fast and winds are excessive. Narrow bays and stagnant areas make the exchange of water in the cage insufficient, and the water quality in the tank may deteriorate, which may cause physiological stress response of the fish. If the water flow is too fast and the storm is too large, the water exchange is too frequent. When water is used for swimming, it will cause physical stress response of the fish, and the cage will be easily damaged. Changes in the water level of cage culture waters should be able to predict that the lowest water depth of the cages should be at least 5 meters deeper than the bottom of the tanks. The area where the cages are set should not contain aquatic plants or there are too many rocks. For ease of management and security, the area of ​​the cage should be set so that workers can arrive and often be observed.
3. Arrangement of cages The cages are preferably arranged in a "one" arrangement and placed perpendicular to the water stream. They must not be arranged in a "checkerboard style" and cannot allow water to flow directly from one cage to another. Taking into account the changes in the water level and the role of wind and waves, each cage uses steel wire rings to connect with adjacent cages. The four corners of each row of cages are fixed with iron anchor wire ropes to prevent wind waves from blowing or due to The water level changes and deviates from the culture area.
Three, rainbow trout's stocking
1. The stock of rainbow trout that is stocked in the quality cages of stocked fish species should have a body weight of 50 g or more, and the specifications should be uniform and free from injury and illness. The main signs of healthy fish species are: uniform color of the entire fish population, no scars, no damage to the rays, and difficult to capture.
2. Stocking of fingerlings The stocking of fingerlings depends on the expected total weight and average individual weight of the rainbow trout in the cage at harvest, and on the optimum fish load of the cage. The optimum fish loading capacity of cages varies with the quality of the culture environment and varies from one fish to the next. Within the range of the optimum fish loading force, a reasonable stocking capacity can be calculated using the formula: Stocking capacity (tail/m3) = The total weight of fish per cubic metre at the time of harvest/the average weight of each fish at the time of harvest.
3. Stocking conditions and operation requirements Fish species must be stopped for food 2 days before stocking and transportation. The temperature of the water from the point of departure and the destination must be approximately the same, and the maximum difference must not exceed 3°C. Rainbow trout stocking is best carried out at a water temperature of 8°C to 10°C. The higher the water temperature, the more severe the stress of the fish body and the more likely to cause death. The transport of fingerlings should be carried out in the spring. It is best to use an oxygenated live fish transporter and pay attention to changes in water temperature and supply of oxygen during transportation. Stocking time should be at the lowest temperature in the morning or when it is raining and cloudy. The whole process of putting the fish into the box should be carried out in water. The operation should be careful so as to reduce the stress on the fish species as much as possible, and prevent the body surface from scratching, slamming and dying. If fingerlings are in good health and careful handling, the survival rate of fingerlings can reach 100%.
Feeding and Storage of Feed
In the process of cage culture of rainbow trout, it is extremely important to feed high-quality pellet feeds. It is necessary to use full-fat, full-grain pellet feeds. The content of protein in feed should be above 40%. The fish species that have just entered the water have not yet formed eating habits, and should be acclimated in time until the clusters actively take food and then reasonably adjust the feeding amount.
In the breeding process, the appropriate particle size should be selected according to the size of the fish body, and the feeding amount should be timely adjusted according to the weight change of the fish body. The feeding time should be selected in the early morning or evening. Observe the rainbow trout's feeding and digestion every day and strictly avoid excessive feeding. Be careful when feeding, slowly feed to the center of the cage, try to avoid feed out of the cage.
Fish feeding behavior is the best indicator of fish health status. Positive fish consumption indicates that their health is good. Therefore, to maintain a strong appetite for fish, it should be considered as the weather, water temperature and digestion, each feeding 80% Saturation is appropriate.
The quality of the feed produced decreases with the prolonged storage time, and the fresh feed required for rainbow trout must be used within one month, and it cannot be purchased at one time for storage. Feeds that do not feed or spoil due to improper transport and storage may be effective in preventing the nutritional disease of rainbow trout. Therefore, moisture, sun protection, and rodent damage should be paid attention to in the storage of feed, and the storage should be kept dry and ventilated.
V. Daily management
The unbalanced growth of rainbow trout is a common phenomenon. It is necessary to conduct a screening once a month to raise the fish by grading, which can improve the breeding efficiency. When the water temperature rises in summer, the depth of the cage should be deepened to reduce the density of the culture, thereby increasing the activity space of the rainbow trout. Inspect the cage daily, measure the water temperature, record the amount of feed and fish feeding conditions, and find that the diseased fish and dead fish are removed in time; the windy windy weather can be checked immediately after the wind stops to see if there is a cage. Damage, repair immediately after discovery, and re-tighten the wire and snap ring screws between the connected cages to ensure that each joint is secure. Always pay attention to the change of water level in the culture area. With the rise or fall of the water level, timely retract and place the anchors and wire ropes at the four corners of the fixed operation platform. It is easy to generate attachments around the cabinet and hinder the exchange of water. When it is found that there are many attachments, net cages should be cleaned immediately and the operation should be light and slow. Do not use too much force, otherwise it will scratch the surface of the fish and cause disease.
Sixth, disease prevention
Rainbow trout is generally not susceptible to disease. The common diseases are mainly fin fin disease and nutritional diseases, and generally occur in early spring. In the early spring season, as the temperature of the water gradually increases, the density of the fish should be properly reduced, and the fish should be sifted in a timely manner so that the fish can be carefully handled, thereby reducing the infringement of fish and human-induced damage. At the same time, adding appropriate amounts of drugs to the feed every week to feed and feed can improve the immunity of the fish population and effectively prevent the occurrence of the disease. If you find that there are fish bodies that have fins, remove them immediately after bathing with potassium permanganate solution to prevent infection. Nutritional diseases are mainly caused by feeding unqualified feeds. As long as the fed feed is fresh and nutritious, it can prevent the occurrence of the disease. As long as prevention and proper measures are taken in advance, various diseases of cage-cultured rainbow trout are less likely to occur.