Grass carp culture density

The stocking density of grass carp (Ctenopharyngodon idellus) with general size of 200g-250g is controlled at about 300pieces / mu, and grass carp will be mixed with other fishes in order to improve the culture benefit, and crucian carp fry with 15-20 fry / kg, silver carp fry with 5-6 / kg and bighead carp fry with about 10 fry / mu will be put in.

The density of fish species with specifications of 200-250g is generally about 300 pieces / mu, because the culture cycle of grass carp takes about 3 years, the cost is higher, and it takes a long time, in order to make rational use of the culture water surface and increase income, now the general farmers will adopt the mode of mixed culture of grass carp and other fish.

1. Pond requirements

The area had better be controlled at about 10-20 mu, the water depth should be kept at 2-2.5 m, and the thickness of the sludge at the bottom should not exceed 20cm. In order to ensure sufficient oxygen content in the water and uniform feeding in the breeding process, every 10 mu pond needs to be equipped with an 3kw aerator and automatic feeding machine.

2. Pond consolidation

In winter, drain the water from the pond and freeze it in the sun for about 20 days. Half a month before putting the fry, pour about 10-20cm of water into the pond, and sprinkle quicklime into the pond at the ratio of 150kg / mu.

3. Release of fish species

Generally choose to put before and after the Spring Festival, before release, use 5% salt water to soak and disinfect the fish for about 10 minutes. The density of grass carp fingerling with specifications of 200g-250g is controlled at about 300pieces / mu, crucian carp fry with specifications of 15-20 / kg, silver carp fry with 5-6 fry / kg, and bighead carp fry with about 10 / mu.

4. Feed feeding

The pellet feed is mainly fed, and the protein content in the feed is required to be about 28-32%. In order to ensure adequate nutrition for grass carp, it is also necessary to feed grass feed. When putting into the feed, we should adhere to the principle of "before roughing and then fine" and "four decisions and four looks". It is best to feed the grass carp once in the morning and evening, and the grass carp can be eaten within 2 hours. From March to June, the pellet feed with 28% protein content was mainly fed, and some green fodder was fed appropriately, and the daily feeding rate was controlled at about 3%. In order to control the disease of fish fry from July to September, the feeding rate of pellet feed with 28% protein should be reduced to about 1.5%. Increase the feeding of grass feed From October to November, after continuously feeding pellet feed with 32% protein content for a period of time, it should be stopped for about a week, and some raw grain feed can be fed during the interval.

In order to prevent grass carp from being infected with hepatobiliary syndrome, some vitamins and other drugs can be properly added to the feed during daily feeding to place diseases and reduce the risk of death from fish disease.

5. Water quality management

When the weather is sunny from June to October, turn on the aerator for two hours from 1pm to 3pm every day, and add oxygen to the pool appropriately in the early hours of the morning. When the weather is continuously cloudy, the opening time of the aerator should be earlier. Regularly add new water to the pool, slowly regulate and control the water quality according to the method of "small row and small advance, changing water many times"; from June to September, add new water to the pool every 3 days, add about 10cm water every time, and sprinkle quicklime into the pool with a depth of 1 m every half a month according to the ratio of 10-20 kg / mu.

6. Disease prevention

Feeding is carried out in accordance with the standard of "combination of pre-coarse and post-refined, rough and green", and daily prevention of grass carp from hepatobiliary syndrome. In addition, red skin disease, Gill rot disease, enteritis and other diseases are also common diseases of grass carp. Generally, they can be treated by internal administration and external treatment. Internal administration mainly refers to feeding grass carp with bait of "Sanhuang powder". The Sanhuang powder is made from 50% rhubarb, 30% Cortex Phellodendri and 20% Scutellaria baicalensis Georgi after grinding and stirring evenly. Each 50kg fish group is fed with 0.3kg Sanhuang flour and flour paste, then mixed with the feed for 3-5 days. External splashing is to sprinkle a certain proportion of bleach, chlorine dioxide and other disinfectants into the pool for 3 consecutive days.

7. Timely fishing

In order to reduce the carrying capacity of fish schools in the pond and promote the rapid growth of small-size fish fry, it is necessary to timely put large-size adult fish in the pond on the market, which can increase the yield to a certain extent. It is usually caught at the end of July when the water temperature is low.