CATDOLL : CATDOLL: What are the conditions for farming rainbow trout?

What are the conditions for breeding rainbow trout?

Rainbow trout is a freshwater fish native to northern North America and the west coast of the Pacific Ocean. It mainly lives in low-temperature freshwater and has high requirements for aquaculture water quality. Rainbow trout is an edible fish that has been transferred to many countries, but has become an invasive species in some areas. China's more than 50 professional rainbow trout farms are mainly distributed in Beijing, Heilongjiang, Shandong, Shanxi, Liaoning, Jilin and Shaanxi.

Rainbow trout has been introduced for breeding in various countries around the world due to its excellent characteristics. Fish ponds for raising rainbow trout vary in shape, but most are rectangular. The appropriate proportion can be determined according to the terrain. A certain slope should be maintained from the water inlet to the water outlet to facilitate water exchange and sewage discharge. The arrangement of water drops between the pools can be arranged according to the terrain classification. The construction of the fish pond can be determined according to the actual situation.

The structure of the fish pond is a brick-concrete structure, and the inner wall is smoothed with cement. The water inlet and outlet are set in the middle and upper part of the fish pond to maintain the water level. The best water temperature in the four seasons is 12-18℃, and the maximum water temperature in summer shall not exceed 24℃. It requires large flow, large flow, large breeding scale and high yield. A flow of 1 liter of water per second has a production capacity of 100-200 kg. A cold water pond fish of the Pacific salmon genus of the salmon family. Rainbow trout is an important cold water fish and is widely farmed worldwide. Because mature individuals have a brown-red vertical line along the lateral line, like a rainbow. The meat is tender, without fine thorns and no fishy smell. It is easy to cook and tastes good. Except for bones, gills, bile and kidneys, the whole fish body can be eaten and is rich in nutrition.

Rainbow trout is very expensive in the international market. The larval stage is mainly composed of zooplankton, benthic organisms and aquatic insects. Rainbow trout farming adopts high-density flow-through fish farming method with high technological content. Judging from the current technical level of rainbow trout farming, it takes more than three years to complete a commercial fish production cycle. The production cycle is long and the investment is high. In order to achieve better economic benefits, it is necessary to improve the variety, increase the growth rate of rainbow trout, shorten the production cycle and reduce costs as much as possible.

The water for breeding must not be turbid, and must be standard cold water or fresh water. Secondly, the water temperature should change between 5 and 25 degrees Celsius. Try to make the change smaller. In addition, a shed should be built in the pond to prevent rainwater from mixing in it.

The breeding conditions are cold water breeding, and it must be fresh water. The water temperature is about 7~20 degrees, and the pH value of the water should be between 6.5~6.8.

The temperature should be moderate, preferably around 13 to 18 degrees, and the water quality should be suitable for rainbow trout, and rainbow trout should be fed some nutritious food.

What are the key points of American rainbow trout farming technology?

American rainbow trout is a cold-water fish belonging to the family Salmonidae. It is native to the Pacific coast of North America and is one of the four excellent freshwater aquaculture species promoted by the Food and Agriculture Organization of the United Nations to the world.

Rainbow trout has a small head, few bones, thick meat, no muscle spines, tender meat, delicious taste and no fishy smell. It is suitable for steaming, boiling, and grilling, and can also be eaten directly as sashimi.

According to relevant experts, rainbow trout should be raised like this:

1. Construction

The survival limit temperature of rainbow trout is 0 to 30 degrees, the growth water temperature is 5 to 22 degrees, and the optimal growth temperature is 12 to 18 degrees. The dissolved oxygen value is required to be maintained above 6 mg/L (should not be less than 5 mg/L), the suitable flow rate for life is 2-16 cm per second, and the pH value is 7-8. Rainbow trout grows fast, has high aquaculture yields, and has good economic benefits. It is especially suitable for high-density intensive water aquaculture in areas with abundant water, suitable water temperature, and rich dissolved oxygen. Mountain streams, groundwater, bottom water of newly built reservoirs, and cold spring water are all suitable. Generally, farms should build juvenile fish ponds and adult fish ponds. Juvenile fish ponds are generally circular, with an area of ​​10-30 square meters and a water depth of 20-40 cm. Adult fish ponds are generally 100-200 square meters, with a water depth of 70-90 cm. There should be a certain slope to use the natural drop of water to increase oxygen. Fish ponds should be of uniform standards, rectangular, and cement structure, which is conducive to feeding, management, and control of fish diseases, in line with the characteristics of rainbow trout that likes to go against the current. It is ideal if the fish pond is built against a mountain, and fish fences should be installed at the inlet and outlet.

2. Feeding and management

Before the juvenile fish grow to 10 grams or 15 grams, they are screened and 40% of the large fish are placed in the back half of the adult fish pond, and 60% of the small fish are placed in the front half of the adult fish pond, so that large and small fish are raised separately. The cement juvenile fish pond should be cleaned with water once a day, and the cement adult fish pond should be cleaned with water once every 5 days. The earthen pond should be flushed for 2 hours a week with water that is exchanged 3 times per hour. At the drain outlet of the fish pond, if the dissolved oxygen is lower than 3.5 mg/L, increase the flow rate or mechanically increase oxygen to supplement the dissolved oxygen in the pond water. 3. Prevention and control of common fish diseases

Before the purchased eyed eggs are shipped, they must be bathed in 50ppm polyvinylpyrrolidone iodine (containing 1% available iodine) for 15 minutes. Oxygenation must be provided during the bath. The bath can kill the viruses on the eggs to prevent the IHN virus.

Symptoms of bacterial gill disease in juvenile fish: The body color of juvenile fish is dark, and they are weak in swimming at the drain or along the surface of the pond wall, and they lose their appetite. The number of dead fish increases day by day. There is mucus on the gills. When observed from the back, the gill cover is open. Treatment: Place the sick fish in a net and bathe them in 1/2000 copper sulfate solution for 1-2 minutes. Place the non-sick fish in the same pond in a net and bathe them in 1/2000 copper sulfate solution for 1 minute. Bath them in 1ppm furan solution for 1 hour. Feed sulfonamide bait. On the first day, add 200 mg of veterinary sulfonamide 6-methoxazole per kilogram of all bait used that day. The dosage for the 2nd to 4th day is 150 mg per kilogram of fish.

Symptoms of enteritis in juvenile fish: black fish body, red anus with mucus, purple intestines, no food or mucus in the intestines. Treatment: Feed sulfaquinoxaline bait, add 200 mg of veterinary sulfaquinoxaline per kilogram of total feed on the first day, and add 150 mg of sulfaquinoxaline per kilogram of fish on the 2nd to 4th day.

Third generation worms: Symptoms of ectoparasitic diseases such as Ichthyophthirius: They mostly occur in juvenile fish weighing less than 50 grams. Especially for juvenile fish weighing less than 5 grams, the water temperature during the onset period is mostly 5-15 degrees. The sick fish turn over and swim rapidly along the bottom or wall of the pond. In severe cases, they gather at the drain outlet, and the flow is weak. The number of dead fish increases. There are white spots on the body surface of Ichthyophthirius, and there is mucus on the gills. Treatment: Sprinkle formalin throughout the pond, make the pond water 1/2000 concentration and bathe for 10 minutes. Before applying the medicine, drain 50% of the pond water, block the drainage outlet, stop the flow of pond water, and then sprinkle the whole pond with the formalin solution prepared in advance. After 10 minutes of bathing, open it immediately and inject new water. This method can both cure and prevent diseases. During the high incidence period, bathe once every 10-15 days according to the same method as Xiansen.

You can go to some aquatic stations to have a look. For example, you can go and see if there is this one.