High-yielding techniques of cultivating grass carp in ponds for two seasons a year

Grass carp (Ctenopharyngodon idellus) is a typical herbivorous freshwater fish. the traditional culture method is artificial mowing and feeding for one season a year. This breeding model has the advantages of high labor intensity, low yield and low benefit. It generally produces 500 kilos per mu and 800 kilograms per mu, with a profit of only 800 to 1000 yuan per mu. Since 2003, the Aquatic Technology extension Station of Gutian County, Fujian Province has used automatic bait feeding machines to automatically feed artificial pellet feed in key fishing villages to raise grass carp semi-mechanized in ponds for two seasons a year, with an average yield of 3920 jin per mu, a culture survival rate of more than 95%, a profit of 3000 yuan per mu a year, and a labor force can manage 10 mu of ponds.

Pond selection

Choose ponds with sufficient water sources, no pollution sources in the upstream, convenient drainage and irrigation, and perennial micro-running water. The size of the pond is 5 mu and 10 mu, and the water depth is 1.5 m ~ 2 m.

Pond disinfection

10-15 days before fish stocking, disinfect the pond with 14 jin / mu rice bleach with water, or sprinkle the whole pond with 150 jin / mu rice lime while the water is hot.

Fish stocking

1. The first season: starting around the Spring Festival, grass carp species are mainly released, with proper mixed culture of carp, carp, silver carp and bighead carp. The stocking density of grass carp, silver carp, bighead carp, bighead carp, silver carp, bighead carp, silver carp, carp, carp

2. The second season: starting after the Dragon Boat Festival, all grass carp species with a tail weight of 3 to 4 taels are stocked with a stocking density of 600 fish per mu, and the general tail weight can reach more than 2.5 jin by the end of the year. Before stocking, all fish species are bathed in 4% saline solution for 10 minutes and 15 minutes to prevent various bacterial diseases and water mildew.

Feed feeding

1. Feed type: the special sedimentation pellet feed of grass carp with crude protein content of 28,30% is selected, the particle size of pellet feed in the early stage of culture is 2.5 mm, and the particle size of pellet feed in the later stage of culture is 3.5 mm. The feed coefficient was 1.6.

2. Installation and use of automatic bait feeding machine: automatic bait feeding machine can be installed near the pond of the management room, and the power switch is installed in the management room. When feeding, as long as you turn on the indoor power switch, the automatic feeding machine can sprinkle the pellet feed evenly into the pond regularly and intermittently according to the set procedure. After feeding the feed (the feeding time of each meal is set to 1 hour), the power supply can be turned off automatically. An automatic bait feeding machine can be installed in ponds with an area of less than 10 mu.

3. Feeding method: the feeding ability of fish is closely related to the water temperature. The feeding ability of fish is weak when the water temperature is low, and the feeding ability of fish is strong when the water temperature is high. Therefore, the daily feeding in the early stage of culture was calculated according to 20.3% of the total weight of grass, carp and carp in the pond, and it was changed to 50.6% in the later stage of culture. In case of muggy heat, cold current, torrential rain and other weather can be reduced as appropriate. Feed 2 or 4 times a day.

Daily management

For the high-density intensive production mode, the daily management work is mainly to maintain good and stable water quality, with emphasis on preventing hypoxia and flooding ponds.

1. Add new water: keep filling water with small flow day and night. In case of serious floating head, the amount of water should be increased.

2. Early pond patrol: the light floating head begins at 5: 00 in the morning and disappears after the sun comes out at 7: 8, which is a normal phenomenon. Heavy floating head starts from 3: 00 in the middle of the night, if no timely measures are taken, it will lead to the death of fish in Fantang at 5 ~ 6 o'clock. Therefore, get up at 3 am to patrol the pond once, especially in Lesser Fullness of Grain, Grain in Beard these two seasons are most prone to heavy floating head. If heavy floating head is found, measures such as adding new water and turning on the aerator to increase oxygen should be taken in time to prevent flooding.

3. Turn on the aerator at the right time: a pond with an area of less than 10 mu is equipped with a 2.2 kilowatt single-phase water jet aerator. When the floating head is light, it can be turned on at 5: 6 am to 8: 9 am when the floating head disappears and then stops. In the two seasons of Lesser Fullness of Grain and Grain in Beard, in case of thunderstorm or muggy weather, the machine should be turned on at 12:00 in the morning to stop at 8: 9 the next day.

Disease prevention and cure

Adhere to the policy of "prevention is the first, prevention is more important than cure". When patrolling the pond, if it is found that there is a grass carp cluster at the inlet and the fish body blackens, it is a sign of disease. At this time, the whole pool was sprinkled with 1 mg / L bleach for 2-3 days to stop the disease. There is generally no disease during the second season, and the main diseases in the first season are grass carp "three diseases" and mackerel hemorrhagic disease.