Good cultivating effect among shrimps

In the middle of cultivating shrimp or middle stocking, it means that the individual smaller shrimp seedlings are placed in a small water area, and after a period of high-density rearing, the shrimp seedlings reach a certain size (2.5 cm or more). Then move into a transitional production measure where the rearing pool continues to be raised. First, the advantages of the middle cultivation 1. Can choose the best fittest to ensure the quality of secondary release. The area of ​​the middle cultivation pool is generally small, the water quality conditions are easy to control, and it is conducive to centralized feeding management. Especially in the northern regions of China, the stocking of early seedlings is often limited by the temperature conditions. The use of the plastic film greenhouse insulation method for intermediate cultivation can solve the above contradictions. 2. Facilitate the management of shrimp farming in the middle and later stages. After the middle-cultivated shrimp seedlings, the accuracy of re-counting is higher. With a larger body shape, the ability to withstand the pressure of the water environment and to avoid the predators is improved, the survival rate is relatively stable, and the feeding and changing can be controlled accurately. water. 3. It is conducive to the growth of the basic food organisms in the pond. The cultivation in the middle delayed the stocking time (about 25 days) of the shrimp seedlings in the rearing pond and won sufficient time for the thorough clearing of the pond and the basic food organisms in the breeding pond. 4. Reduce the pressure of organic pollution in shrimp ponds. As the shrimp pond cultivation period is shortened, the pollution brought by the cultivation of the field is also greatly weakened, which is favorable for delaying the onset of shrimp disease in the shrimp culture pond and the aging process of the pool body, and is favorable to the aquatic environment of the culture area. Second, the middle of the cultivation method 1. Breeding pool. The middle cultivating pool is generally earthy, rectangular, with an area of ​​1000 to 3,000 square meters, a horizontal span of no more than 30 meters, and a pool depth of about 1.5 meters. In order to improve the cultivation efficiency and prevent adverse effects brought about by the low temperature, oxygen-increasing equipment should be installed in the pool, and a plastic greenhouse should be added above the pool. 2. Incubation time. The time of intermediate cultivation is generally 20-30 days before the shrimps are officially stocked. Seedlings emergence and seedlings specifications should be determined according to the plan requirements and management capabilities, usually in the water temperature of 22 ~ 25 °C, the pool gas (or daily water volume of 20%), there are sufficient nutrient guarantee conditions, shrimp density per cubic meter of water About 300 or so (200,000 pigs per mu), the body length of the shrimp can grow from 1 cm to 2.5 cm in 25 days. 3. Scientific management. The content of management developed in the middle is almost the same as the cultivated production, mainly including disinfecting ponds, feeding, inflating, changing water, and disease prevention and control. However, due to the small size of the water body and the high density of shrimp seedlings, the requirements for management are more stringent. During the cultivation period, the daily water exchange rate should not be less than 20%. The minimum water temperature must also be close to the saturation point. 4. Seedling method. There are two ways to raise seedlings in the middle. One is that the intermediate cultivation pool is adjacent to the low-formation rearing tank. After the gate is opened, the shrimp can flow into the pool with the water. The disadvantage is that the number is difficult to determine; the second is the use of long-sleeved cages, and the shrimps reach a certain density. Afterwards, remove it by hand at the net, count it with a weighing method, and transfer it to the rearing tank. Finally, we must do a good job in the post-processing of the intermediate cultivation pool. After high-density medium-cultured shrimp ponds have been “contaminated”, they must be re-sterilized, cleaned and treated with fertilizers before they can be used for further cultivation, otherwise shrimp growth will be affected. The desalted shrimp in the nursery room should be raised (ie, desalted) before the formal culture. The method is as follows: (1) The required specification for the purchase of the seed is 0.8-1.0 cm, after preliminary dilution to 1.005 (7.5 ‰). 2 In the corner of raising shrimp ponds, a number of square meters of holding pools shall be fenced with color strip cloth (or soil). The area of ​​holding ponds shall be designed to be placed at a height of 1000 tails per square meter with a water depth of 0.5 meters or more. Installation of gas heads in temporary holding pools requires continuous supply of oxygen, and at the same time, the salinity of the holding tanks is adjusted to 5‰, and the water quality is disinfected and watered in advance (using dibromohydantoin 0.210-6～0.310-6 for spilling; With bio-fertilizer, 4 kg/acre of algae will make the pool water brown. 3 From the 3rd to the 4th day after the seedlings are released, 5 to 10 cm of freshwater is added to the holding tank every day until they overflow into the holding pool and enter the large pool. 4 The feeding is started the night after the seed is placed in the holding pool. 40 to 60 mesh microencapsulated shrimp can be used, and the 0th shrimp can be fed with a 40-60 mesh sieve and the filter juice can be fed. After 4 days, the 0th shrimp can be fed directly. The initial feeding amount is 5 to 10 g/ten thousand shrimp, which is fed 4 to 5 times a day, and the daily feed volume is increased by 20% to 30%. 5 General to the 10th to 15th days After the shrimp grows to 3 cm, draw 5 to 6 gaps in the holding pool (opening several gaps in the mud wall) and let the shrimps swim to the rearing pool. (Provincial Fisheries Technology Promotion Station)

Yeast Selenium

Yeast Selenium,Selenium Enriched Yeast,Selenium Yeast,Selenium Yeast Powder

CANGZHOU HUAYOU IMPORT & EXPORT TRADE CO., LTD. , https://www.huayoutrade.com