Techniques of rainbow trout culture in Jianshui in South China

1. Aquaculture conditions 1. According to the living habits of rainbow trout, choose mountain streams with good ecological environment and high forest coverage around (more than 80%), and the topography of the pond should be different. It requires a large amount of water, the water quality conforms to the fishery water standard, the water temperature is low, and the maximum water temperature in summer is no more than 24 ℃. 2. The quality of mountain stream water in the construction of reservoir is easy to be attacked by Rain Water, resulting in turbidity and bacterial infection, so it is more important to build a reservoir, and water purification equipment can be installed under certain conditions. Generally, the dam is intercepted at the diversion mouth, and then the 160mm diameter PV pipe is used to divert water from the bottom of the dam into the reservoir, which is treated as aquaculture water after sedimentation. 3. The intensive culture mode of running water pond is adopted in the culture process from fish species to adult fish. The fish pond is a rectangular cement pond with a coagulation structure. The fish pond is built in the upstream of the current, and the adult pond is built in the downstream of the current. The fish pond area is 30-100m 2, the water depth is 0.3-0.5m, and the adult fish area is 50-200m, and the water depth is 0.5-0.8 m. The ratio of length to width of the fish pond (3-5): 1 is more suitable, with a slope of 3% to 5% from the front to the back of the pond, which is convenient for sewage discharge and pond cleaning. Generally build parallel pool, there should be a drop when building series pool, to achieve the purpose of reducing water and increasing oxygen, 2-3 rows are more suitable, too much series is easy to spread diseases. 4. The injection and drainage system is set up at each end of the opposite end of the fish pond to set up an independent intake and drainage system. The width of the inlet and outlet of the fish pond is about 0.5 m and 0.6 m, while that of the adult pond is about 0.8 m and 1.0 m respectively. The inlet is equipped with 60 mesh sieve silk to filter the water for aquaculture, and the discharge outlet is generally equipped with two layers, the first layer is the fish fence, the mesh size depends on the size of the cultured rainbow trout, and the second layer is the gate that controls the water level. The tail of the fish pond is provided with a "V"-shaped sewage trough or a long-shaped sewage drain, and the PV pipe is buried to discharge the sewage out of Shantou. 5. Setting up sunshade net because the water temperature of mountain stream is easy to fluctuate by climate change, especially in summer, the water temperature rises rapidly with sunlight exposure, so it is particularly important to set up sunshade net in high temperature season. (2) Seedling stocking 1. Fish pond treatment. Disinfect fish ponds with chlorine dioxide 0.5 g / m3 before stocking, and soak and clean the newly built fish ponds with oxalic acid or acetic acid for 7-10 days before disinfection. 2. Seedling stocking. The eye eggs of rainbow trout introduced from Beijing are concentrated to 3-5 cm in the city cold water seedling breeding base and transported to each breeding site with oxygen-filled bags or fish baskets. The temperature difference of fish should be less than 2-5 ℃ before entering the pond. Before entering the pond, the fish should be soaked in potassium permanganate (8-10 mg / L) or formalin (25 × 10-6) for 15-20 minutes to kill the pathogens and parasites carried on the fish. 3. Stocking density. Rainbow trout release is generally divided into two stages, fish breeding period (specification is 3-5 cm / tail), 500 fish / m ~ 2; intensive culture to more than 50 grams into the adult fish breeding period, 50-80 fish / m ~ 2. During each stage of culture, rainbow trout should be divided into ponds and sparse density according to the growth of rainbow trout. Third, feeding management. 1. Feed feeding. The feed can be self-proportioned or fed with compound feed. Self-made feed is mainly animal feed, mainly fish meal, meat and bone meal, yeast, animal viscera, accounting for 50%, 70%; plant feed, soybean meal, corn meal, wheat flour, etc. account for 30%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50%, 50% Formula feed is mainly fed with autocratic rainbow trout feed. Timely add 1% antibiotics, 2% salt, and trace amounts of potassium iodide (0.02 g / kg feed) and cobalt dichloride (0.06 g / kg feed) to the feed. From July to September, licorice, Banlangen and other Chinese herbal medicine juice were mixed in the feed, which was beneficial to spend the summer. The feed is made of floatability, easy to observe and not easy to pollute the water quality. Feed feeding amount the breeding period accounts for 3% of the body weight of rainbow trout, with 3-6 times of bait per day; the adult fish accounts for 2% of the body weight of fish during the breeding period, and 2-3 times of bait per day. Specifically, it should be flexibly mastered according to the physique of fish, water temperature, weather and so on, and the feed amount should be adjusted every 7-10 days according to the weight gain of rainbow trout. Generally bait in the front of the fish pond, grasp the principle of slow, fast and slow when feeding, and watch closely so that the rainbow trout can reach 80% satiety. 2. Water quality management. ① keeps the current constant and unobstructed, the water level is 30-50 cm, the flow rate is 2-4 cm / s, the flow rate is 2-3 times per hour, and the water level is 50-80 cm, the flow rate is 6-10 cm / s, and the flow rate is 5-6 times per hour. ② frequently brushes the fish fence and discharges once a day, thoroughly cleaning the pond once every 7-10 days. Rainbow trout culture in ③ mountain stream should especially strengthen the management of rainy season to avoid the entry of muddy water, especially rainbow trout seedling stage is more sensitive to muddy water, which is easy to cause dead fish. Turn off the water source in time, set up oxygen equipment, or put an iron screen on the surface of the fish pond and between the water injection mouth, and place sponges on the iron screen to purify the water quality. ④ summer high temperature mountain water is affected by air temperature, and the water temperature often rises to more than 25 ℃ at 2-3 pm on a sunny day. At this time, it is necessary to increase the amount of water exchange, use sunshade nets, and if possible, draw groundwater to cool down, so as to ensure the rainbow trout to spend the summer smoothly. 3. Sifting in time. Rainbow trout should be sifted and raised in time after one month, so as to keep the specifications of the same pond neat, enhance the feeding rate of rainbow trout and improve the feed utilization rate. Stop eating for half a day before screening and bring water during operation to avoid mechanical injury and infection of fish disease. 4. Daily management. With the growth of rainbow trout, the sieve silk or iron gauze net on the fish fence should be changed timely, so that the mesh size of rainbow trout should be in line with the specifications of rainbow trout, and the breakage and loopholes should be replaced in time to prevent rainbow trout from escaping. Patrol the pond once in the morning, in the middle and in the evening, observe the activity of rainbow trout, record the water temperature of the pond, find that the feeding or activity of rainbow trout is abnormal, check the fish in time, treat the disease as soon as possible, and fish out the dead fish as soon as possible.