Stingray has become a breeding species for many farmers in Yishui County, Huai'an City, Jiangsu Province. However, the author found in the guidance of the household that many farmers in the breeding process have been intensively pursuing high yields, and they have continuously put too much into the water. The bait, fertilizer, etc., will not only increase the cost of aquaculture, but will also deteriorate the water quality, affect the growth of yellow catfish, and ultimately lead to a decrease in aquaculture benefits. Through the understanding and exchanges of several demonstration households in the county, the summary of several more successful experiences in reducing the cost of stingray breeding is described as follows:
1. Thoroughly clean and disinfect the old and new ponds in the clear pond. Old ponds should be cleared of excess silt, leaving only 10 cm of sediment. Ten days to 15 days before the stocking of fish species, clearing ponds are disinfected with drugs to kill pathogens and predators in the aquaculture waters. Generally, two methods can be used: dry clear ponds or water clear ponds. When clear ponds are cleaned, about 75 kg of quick lime or 4 kg to 5 kg of bleaching powder can be used per acre; 150 kg of quick lime can be used per acre when a water clear pond is used. About the Quanchiposa, try to make the bottom of the pool with lime and mix well to completely kill parasites, pathogens and wild fish, etc., reduce competition for food, improve feed utilization.
2. Reasonable stocking density can improve feed utilization. Appropriate collocations can make full use of feed and improve feed use efficiency. To make the survival rate of stingray aquaculture high and the feed less wasteful, it is necessary to control the stocking density and the stocking of fish. When fingerlings are released, large-scale fingerlings of about 30 grams per tail should be selected for adult fish rearing. With the continuous growth of fish, in order to adjust the breeding density and improve the benefits, the market can be launched in batches and caught in rounds to adjust the amount of fish in the water and increase the feed return.
3. Science feeding In the stingray breeding process, inputs affect both the growth of the fry and the changes in water quality. If the amount of feed in the production is greater than the food intake, it will not only result in wastage of the feed, but also increase the cost of aquaculture production, and it will lead to pollution in the aquaculture water environment. If the amount of feed is lower than the feed intake, the demand for nutrients for the rapid growth of cultured objects cannot be satisfied. The growth is hindered and the effective utilization of the bait is reduced accordingly. Practice has shown that a reasonable feeding plan and the farmer's experience are the effective means to ensure the appropriate amount of feed. The amount of bait that should be thrown every day should be flexibly grasped by the producer based on the circumstances of the day, climate, water temperature and other environmental conditions. The whole feeding process should be divided into three phases: the first phase of 5 and 6 months of daily feeding 4 times, the daily feeding rate of 3% to 5%; the second phase of 7, 8 and 9 months of feeding 3 times, The bait rate is 2%~3%; the third stage is to feed 2 times after October, and the bait rate is 2%. The feeding needs to be “Four Sets†and “Four Looksâ€, and the feeding time and times per day depends on the weather. Water temperature conditions may vary. It is advisable to eat the stingray after the specific feeding amount without leaving it. In addition, because of the large splitting of the yellow snapper, the particle size of the fish should be increased accordingly. The particle feed with a particle size of 2.0 mm can be used as an open feed. The fish size can reach 5 mm or more. The use of a hard, hard granular diet requires that the pellets have 15 minutes of stability in water, whereas the use of a floating bait will improve the feed utilization.
4, regulate the quality of water, raise the fish to raise water, the quality of the water affects the speed of the growth of the sturgeon and bait coefficient. Stingray prefers fresh water quality, good water quality, rapid growth, less disease, can make full use of bait, and reduce the bait coefficient. Throughout the entire production process, we should always adhere to the cultivation and maintenance of fresh water, adequate dissolved oxygen, and timely detection of abnormalities, such as adding new water, changing water, or applying water quality improvers. In the middle and late period of cultivation, the water in the pond should be changed from 1/3 to 1/2 every half a month, and when the water enters the water, the 80 mesh screen should be used to cover the inlet to prevent miscellaneous fish from entering. The pond with 5 acres of water surface is equipped with two 1 Kilowatts of aerators are usually open in the morning and in the afternoon.
5, daily management insist on daily inspection of the pond. Observe the fish’s activity based on water quality, weather, food intake, etc., remove the sick fish and dead fish debris in time, and keep the water in the pond clean. Disinfect the food field once a week, pay attention to changes in water color and water level, check whether the inlet and outlet ports are in good condition, so that timely repairs can be carried out. Place some water lotus around the pond to accommodate the life habits of the stingrays inhabiting the bottom of the pond during the day and swimming out of the water at night. Through meticulous management, the stingray keeps the fastest growth rate, thereby reducing costs and achieving maximum economic benefits.
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