Culture techniques of grass carp in ponds

Grass carp is one of the four major domestic fish in freshwater culture in China. Grass carp cultured in ponds has the characteristics of low cost, less labor, fast growth and easy management, and the delicious and thick meat of grass carp has gradually become a hot spot of consumption. therefore, the use of pond grass carp culture is a feasible way to improve economic benefits, let's take a look at the pond grass carp culture technology!

Pond conditions of grass carp

1. Pond conditions: the pond is required to be far away from the pollution source, with an area of 5 to 10 mu, a flat bottom, a loam soil with a little leakage, a sediment of 10 to 20 cm and a water depth of about 2 meters. Each pond should be equipped with a 3-kilowatt turbine aerator and a 4-inch water pump to prepare for timely water exchange and oxygenation.

2. Decontamination and disinfection: grass carp have more diseases, and the pond is more prone to epidemic. At the same time, the elimination of miscellaneous fish is an important measure to ensure the normal feeding of grass carp and save feed. The specific method is to sprinkle the whole pool with 100 kg quicklime pulp per mu in the case of dry pond (5-10 cm of stagnant water), or sprinkle it in the whole pool after dissolving with 10 kg of bleach in warm water, so as to completely kill the disease-causing bacteria.

3. Water quality requirements: the pH value of pond water is 7.5-8.5, the transparency of pond water is about 30 cm during the peak culture period (June-September), and the oxygen consumption of organic matter is 18-20 mg / L.

Seedling restocking of grass carp

1. Seedling selection: grass carp should choose individuals with golden color, harmless appearance, lively and strong, weighing about 100 grams. At the same time, because the two major diseases of grass carp bleeding and enteritis are easy to infect the same year's fish species, 2-year-old seedlings should be the best in the selection of seedlings.

2. Fish stocking: grass carp species are generally stocked with 800 to 1000 fish per mu, with 100 silver carp fingerling ranging from 250 grams to 500 grams, not with or less with carp, in order to avoid grazing with grass carp. In addition, fish species should pay attention to body surface disinfection before entering the pond.

Feed matching of grass carp

1. 50% of rice straw, 25% of rice bran, 25% of bean cake, and 10 kg of flour scraps are added to the above mixture every 100 kg as binder. the crude protein content of the feed is 23.35%, the feed coefficient is 2.8, and the feeding specification is about 0.05 kg per tail.

2. 50% rice straw, 22.5% rice bran, 5% wheat bran, 15% bean cake, 5% fish meal, 1% bone meal, 0.5% salt, 1% vitamin additive, 18.78% crude protein content and 2.4 feed coefficient.

3. Flour 30%, rice bran 8%, wheat bran 38%, bean cake 10%, fish meal 10%, yeast powder 2%, premix 2%, feed coefficient 1.9, if green feed coefficient is 2.2.

4. Flour 30%, fish meal 10%, soybean cake powder 15%, wheat bran 25%, rice bran 20%. Under the premise that the total amount of the basic diet remains unchanged, 12% sweet potato powder, 0.5% salt, 2% auxin, 2% calcium hydrogen phosphate and 4.8 feed coefficient can be added according to the actual situation.

Feeding and management of grass carp

1, feed feeding: mainly feed pellet feed, feed protein content of 28% 32%, auxiliary green feed. Feed feeding follows the principle of "pre-coarse and post-refined" and "four fixed and four look". It is generally fed twice a day, and it is appropriate to finish eating within 2 hours and feed 80% of grass carp. After feeding pellet feed continuously for a period of time, the pellet feed should be stopped for one week, and the raw grain feed should be fed at intervals. Usually pay attention to adding appropriate amount of vitamins and other drugs in the feed to avoid a large number of deaths caused by diseases such as hepatobiliary syndrome of grass carp.

2. Water quality management: correct use of aerator, sunny and windless weather from June to October, turn on aeration for 2 hours at 1: 3 pm every day, and increase oxygen in the early morning. Oxygen should be increased early on continuous cloudy days. Add new water to the pond at the right time, and adopt the method of "small row and small advance, changing water many times" to gradually control the water quality. From June to September, add fresh water once every 3-5 days, about 10 cm each time, and sprinkle it with 10-20 kg quicklime in the whole pool every 15-20 days.

3. Disease prevention and control: the method of "combination of pre-coarse and fine, fine green" was adopted to control the occurrence of grass carp hepatobiliary syndrome. Grass carp common diseases are red skin disease, Gill rot disease, enteritis disease, generally take internal and external splash treatment, external splashing is mainly bleach, chlorine dioxide and other disinfectants, continuous use for 3 days. Oral administration with "Sanhuang powder" bait is better, every 50 kg of fish reuse Sanhuang powder (rhubarb 50%, Phellodendron Phellodendri 30%, Scutellaria baicalensis Georgi 20% crushed powder and stir well) 0.3 kg mixed with flour paste and mixed into the feed for 3 days.

4. Timely fishing: timely catching and listing of large adult fish is an important measure for high-yield grass carp culture, the main purpose is to reduce the fish carrying capacity of the pond water and promote the rapid growth of pond fish in the later stage. It is usually caught once at the end of July and when the water temperature is low in the early morning.