Grass carp farming "five steps"
Grass carp is one of the four major domestic fishes of freshwater culture in China. Its meat is sweet, warm, and has the effect of warm stomach. It is bile and bitter, cold, and has antihypertensive, expectorant and mild antitussive effects. Grass carp is a typical herbivorous fish. It inhabits rivers and lakes in the plains and has swift habits during the reproductive season. Grass carp grows rapidly, has a wide source of feed, and has a good breeding efficiency. In this issue, a group of grass carp technology was introduced for reference by farmers.
first step--
Pond water quality requirements
In the spring, cloudy and mildew rain often occurs. The air pressure is low, the water body is prone to lack of oxygen, the pond should be strictly cleared and disinfected, the grass carp itself has more diseases, the intensive culture ponds are more prone to outbreaks of epidemics, and the miscellaneous fish are eliminated to avoid feed loss.
The pond is required to be far away from the source of pollution, with an area of ​​5 to 10 mu. The bottom of the pool is flat, and the bottom soil is preferably loam. A slight leakage is preferred. The sediment is 10 to 20 cm and the water depth is about 2 meters. In the case of dry ponds (5 to 10 cm of water), 100 grams of lime slurry per acre is poured on the whole pond, or 10 kg of bleaching powder is used in the mu, and the whole pool is splashed when dissolved in warm water, so that no dead corners are left, completely killing. Pathogenic bacteria. Sprinkle quicklime regularly, usually every 20 months by 20kg per meter of water depth, or 1ml of bleached powder.
Each pond should be equipped with a 3-kilowatt impeller-type aerator and a 4-inch pump to prepare for water changes and aeration. The pH of the water should be maintained between 7.5 and 8.5. The transparency of the pool water should be maintained at about 30 cm between June and September, and the organic oxygen consumption should be 18-20 mg per liter. Plan to add water and change water, inject fresh water once every 10 days, each time injecting 20 to 30 centimeters, to mid-July, depending on the actual situation, change the water once, changing the water volume is 1/2. From June to mid-August. Grass carp is easy to lack of oxygen floating head, noon on sunny days to open the aerator for 2 to 3 hours, the early morning boot 3 to 4 hours, cloudy day and night boot once to prevent fish floating head.
The second step -
Dry pond species breeding
After wintering, fish ponds generally show aging and weak acidity. Therefore, when the fish pond water temperature gradually rises and stabilizes at 13°C～15°C, fish pond water quality should be treated as follows: The pond water level should be appropriately reduced to facilitate a rapid increase in pond water temperature; in fine weather, aerators should be ventilated for 1 to 2 hours at noon, and quicklime or microbial preparations can be used to improve the water quality of ponds.
Grass carp species should be golden colored, with no injuries, lively and robust, individuals weighing about 100 grams. Since the grass carp hemorrhage and enteritis two diseases are susceptible to the current fish species, it is better to choose 2 instar seedlings. Before the fish species enter the pool, attention should be paid to surface disinfection. When stocking, the fish were soaked with 3% saline to immunize the grass carp.
When the fishes are released, 250 grass carp tails weighing 150 to 200 grams per acre are placed. Compared with high-density and large-scale stocking, this mode of delivery can significantly reduce the cost of fish species and save costs by 50% to 73%. On the other hand, it avoids the high-loading of fish in high-temperature water and is prone to flooding. Dead fish phenomenon.
The other species is 800-1000 fishes per acre, with an individual size of 250-500 g per 100 species of carp, 15 species of carp, and no or less colostrums to avoid catching with grass carp.
third step--
Broodstock nurture
After the beginning of spring, fish ponds gradually increase in temperature, and fish start feeding. At this time, they should eat early, feed fresh and high-quality feed, ensure that fish can eat early, promote physical recovery, increase disease resistance, and promptly promote fish growth. Accelerate gonad development in broodstock and increase aquaculture production and benefits.
Should be patrolling the pond to avoid floating heads. Oviparous broodstock, oxygen consumption is relatively high, to keep the water quality of fish ponds have higher dissolved oxygen, once the pool water lack of oxygen, broodstock floating head, it will affect the broodstock maturation and spawning, and even lead to broodstock do not produce , seriously affecting the entire year's production.
Strengthen flushing and promote broodstock development. When the water temperature is stable above 15°C, the stimulating water flow to the broodstock will help the broodstock grow and mature, and the mature broodstock will lay eggs successfully.
Effective control of fish diseases, excessive application of pesticides, excessive application of pesticides, will affect the maturation of broodstock maturation, and even affect the quality of spawning hatching fry, should strictly control the amount of parent fish pond application. After the winter of broodstock, some broodstock may suffer from frostbite and brucellosis, and it is necessary to remove dead and sick fish in time to avoid polluting the water.
the fourth step--
How to Feed Science
Feed protein content is an important factor affecting the economic efficiency of grass carp culture. Practice has proved that when the feed protein content is about 30%, it can not only guarantee the rapid growth of grass carp, but also reduce the feed cost, and the best breeding efficiency.
The feed used for pond intensive culture of grass carp is mainly based on fish feed, supplemented by green feed. The compound feed consists mainly of fishmeal, soybean meal, wheat bran, sub-powder, corn, and refined grass, and is compounded with mineral salt, multi-dimensional and amino acid compound additives, requiring comprehensive feed nutrition, including crude protein 20%, crude fat 4%, 40% of carbohydrates, 8% to 10% of cellulose, green feed fed alfalfa, ryegrass, Sudan grass, dry grass, aquatic grass, etc., require fresh grass for the grass carp to digest.
Feeding high-quality feed can cause grass carp to have less disease and rapid growth. Intensive culture ponds should strictly adhere to the "quality, quantity, timing, and fixed-point" feeding. Routine feeding is from 2 to 4 times daily from mid-March to May, 3 times daily from mid-June to August, and 4 times from mid-August to October. From June onwards, feed green feed once a day. The amount of feed should not be too large. It is advisable to use 7-8 to prevent overgrowth or hunger.
Grass carp eat fierce and bulimia, one-time feeding too much prone to feed in the intestines to expand the fish to death. The daily feeding amount was 1.5% to 1.8% of the body weight of grass carp, which was fed three times. In order to prevent the uneven growth of individual growth due to uneven feeding, the grain feed should be 4 mm in diameter and the time for each feeding should not be less than 45 minutes. Try to make all grass carp obtain feed as much as possible.
the fifth step--
Epidemic prevention and control
Intensive patrol ponds, timely control of pool fish activities and eating conditions, to master the changes in water quality, so that "disease-free early prevention, early treatment of disease." Grass carp common diseases are red skin disease, gill disease, enteritis disease, etc., generally take the combination of oral treatment and external sputum treatment, exfoliation mainly in bleach, chlorine dioxide and other disinfectants, used in conjunction for 3 days; oral administration to "three "Yellow powder" bait effect is better, every 50 kg of fish body weight with "three yellow powder" (rhubarb 50%, Huang Bai 30%, Huang Qi 20%, crushed into a powder after stirring) 0.3 kg mixed with the flour paste and mix in the feed Feeding, use 3 to 5 days.
Sulfahydrazine can also be used to make floating feed, that is, every 5 grams of sulfamethoxazole mixed bran 1 kg, plus bark powder or sweet potato flour 3 two, with hot water to reconcile, pressed into small pieces, dry for later use. The drug baits were mixed in the granules. On the first day, 1 gram of medicine was used per 10 kilograms of body weight of the pond fish, and the dose was halved in the second to sixth days. Once a day, 6 days a cycle, every 1 month to 1 and a half months feeding a cycle.
After winter, some fish may suffer from frostbite and other diseases such as water mildew, etc. It is possible to use 100mg of mucilage net per mu for sprinkling the whole pond and splash it with gallnut concoction; use the aforesaid bait feeding method to prevent enteritis disease; use poultry red mucilage Each gram contains 1 million units of the first day Quanchiposa 0.07 million international units, the next day, powdered baits for oral administration, 1 g per 100 kg of fish medication, halved in 2 to 6 days, can cure rot disease; , Furazolidone treats complications of enteritis and gill rot. The specific method is to use gallnut boiled liquids and even splashed the whole pool. At the same time, feed furazolidone for 6 days, 1 mg per 100 kg per day.
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