At present, most crab farmers still adopt the rapid crab cultivation method that was cultivated in the year when the early-stage seedlings were cultivated in the same year. This has resulted in small size, poor quality, low price, and weak market competitiveness. In view of this, the author advocates the idea of ​​“climbing crabs and raising crabsâ€. During the operation, we concluded that the key to nurturing crabs is to control their growth speed. First, pond conditions. The area of ​​the pond is 667~1334 square meters (1~2 mu). The water source is sufficient, and the drainage (consisting of two sets of channel facilities) is convenient. The water quality is fresh and pollution-free. The ponds and weeds should remain abundant. If they are lacking, they should be fished in time. Transplantation of water peanuts, Vallisneria, etc., water plants control the total area of ​​the pond about 40% to 60%. Second, anti-escape facilities. As juvenile crabs have strong turbulence and phototaxis, the water inlets and outlets are tightly sealed with tight meshes to prevent crabs from running, and 60 cm of calcium-plastic plates are used around the pond to prevent escape. The inside inclination is 5 degrees. Third, the selection and transportation of crab seedlings purchase time. In the middle of May, it is difficult to achieve the desired results too early or too late. The selection of high-quality crab seedlings can be performed using the "see two questions and three investigations" method. A look at the appearance of crab seedlings: the body is complete, uniform in size, and powerful in activity; the second asks the finger to ask the source of the crabs, and the second asks the desalination time. Generally, the river crabs of the Yangtze River after 5 to 6 days of desalting can be cultured; The investigation refers to the investigation of the original records of the nursery, the status of the parent crabs in the second pool and the parents in the pool, and the investigation of the medication in the field. When crab seedlings are transported, the bottom of the crab seedlings is placed on the bottom of the box, and the crabs are placed on the top of the crabs for dry transport. Each box can hold 0.5 to 0.75 kg of seedlings. After 24 hours, no damage is caused. Fourth, the cultivation of young crabs In order to improve the utilization rate of crab seedlings, the crabs are first cultivated in the middle, and then the crabs are cultivated in separate ponds. That is, 2 to 40 thousand juvenile crabs per 667 square meters. After the middle cultivation, the survival rate of the crabs was improved by 10% compared with direct investment. V. Premature control and strengthening management Preventing precocious puberty is the key to nurturing deduction crabs. Therefore, in the whole process of nurturing crabs should be done: 1. Control density. Overstocking is too dense and the size of buttoned crabs is too small. When stocking is too thin, the proportion of precocious puberty is high. The appropriate density is 20,000 to 40,000 to 2 to 40,000 young cats that have been reared in the middle, ie, 1 to 2 kilograms. 2. Water quality supervision. Generally, change the water once every half month, splash lime 1 time, strengthen the water quality management in high temperature season, change the water when the shell is forbidden. 3. Reduce accumulated temperature. In the summer season, increasing water depth can control the accumulation of effective accumulated temperature of young crabs. 4. Reasonable feeding. When the crabs first entered the pool, they were fed a small amount of animal feed, which accounted for 20% of the body weight of the crabs. Afterwards, the amount of bait was reduced step by step and was generally controlled at about 8% to 10%. At the same time, the ratio of animal feed was reduced, and plant food was increased. . 5. Winter management. Before winter, the pond water level is increased to 1.2~1.5 meters, and at the same time, 100 kg of fertilizer per 667 square meters of manure is used to check the water quality regularly. 6. Disease prevention and control. It is mainly prevention, focusing on the prevention of hydromycosis, ciliate disease, rotten limb disease, etc. We must also prevent ferocious fish and rat snakes from predators. 7. Get caught for sale. Before and after the Spring Festival, the time of arrest was used to stimulate the water, catch cages, and catch dry ponds. As long as the cultivation techniques are in place and properly handled, generally about 10,000 crabs can be cultivated per 667 square meters, and the high-yielding ones can reach 1.3 to 15,000, with relatively obvious economic benefits. Vitamins are a type of trace organic substances that humans and animals must obtain from food in order to maintain normal physiological functions. In terms of physiological functions, vitamins are neither a raw material for tissues nor a substance for supplying energy, but they are an indispensable substance for the body. It has many types and different chemical structures. Most of them are the components of the coenzyme (or prosthetic group) of certain enzymes. They are the indispensable compounds for maintaining the normal growth (growth, health, reproduction and production function) of the body. It plays a catalytic role in the body to promote the synthesis and degradation of major nutrients (proteins, fats, carbohydrates, etc.), thereby controlling metabolism. Vitamins are essentially low-molecular organic compounds. They cannot be synthesized in the body, or the amount synthesized is difficult to meet the needs of the body, so they must be supplied from the outside. The daily requirement of vitamins is very small (usually measured in milligrams or micrograms). They are neither a raw material for body tissues nor a substance for energy supply in the body. However, they do not regulate material metabolism, promote growth and development, and maintain physiological functions. Vitamin, Vitamin C, Vitamin E, Vitamin K2, Vitamin K2 MK-7, Vitamin D3 Xi'an Gawen Biotechnology Co., Ltd , https://www.ahualyn-bio.com