Giant River Prawn Farming Techniques and Cost Analysis Per Mu
In recent years, the farming industry has been one of the hot topics among people. Many people are no longer satisfied with the life of going out to the cities to work, so they identify their goals and start their own arduous entrepreneurship. Shrimp is one of the most common foods in our lives, and it is loved by many people. Naturally, this type of farming has become the first choice for most people.
Giant River Prawn Farming Techniques
1. Water quality management
In the early stage after releasing the fry, the generally required water quality indicators are 7.0≤pH≤8.5, ammonia nitrogen≤0.4mg/L, nitrite≤0.05mg/L. It is recommended to fertilize the water appropriately, with transparency≤40cm. In the mid-stage of farming, it is recommended to regularly apply quicklime (5kg/mu) and supplement fertilizer in appropriate amounts, at least 2 times per month, so as to maintain proper water fertility and avoid the appearance of blue-green algae. Regular use of “Telimie” can effectively prevent and control blue-green algae and black gills.
2. Substrate management
Most farmers in the south feed compound feed and add a small amount of wild trash fish (cooked or crushed) to feed together. Long-term feeding of high-protein bait causes large amounts of organic debris to accumulate at the bottom of the pond, which is very likely to breed large numbers of ciliates. As the prawns grow, their activity increases, the effect of turning over the pond bottom becomes more and more obvious, algae become fewer and fewer, water eutrophication becomes more and more serious, and blue-green algae are very likely to breed. Therefore, stable water fertilization during the seedling stage is particularly important.
3. Management during the molting period
Giant river prawns generally choose to molt in concentrated fashion at dawn or dusk in the shallow water areas of the pond. The molting time increases as the shrimp body grows; the larger the shrimp body, the longer the molting time. Under normal circumstances, a prawn with a body length of 5cm can complete one molt in only 3 seconds, while a prawn with a body length of 12cm needs about 2 minutes to complete one molt. The longer the molting time, the higher the probability of being preyed upon or cannibalized. Actual production has proven that giant river prawns have relatively strong stress resistance, but the loss rate during the molting period is relatively high (disease loss rate<10%, while molting loss rate is about 20-40%). How to increase the yield per mu and effectively control the molting loss rate is especially key.
4. Daily management
Persist in patrolling the pond in the morning and evening, checking and observing changes in the water environment of the shrimp pond, shrimp activity and feeding, whether shrimp diseases occur, pond leakage, and whether there are natural enemies, and take corresponding measures promptly when problems are found.
Cost Analysis Per Mu for Giant River Prawn Farming
Cost indicator: below 4200 yuan per mu (shrimp cost below 14 yuan per kg), of which:
1. Disinfection and pond clearing cost: 100 yuan/mu;
2. Shrimp fry: calculated at 250-30 yuan per 10,000 tails, 40,000 tails is 1200 yuan/mu;
3. Feed: feed coefficient is 2·2-2·3, using self-mixed feed, calculated at 3 yuan per kg of feed, feed cost is 1980 yuan/mu;
4. Other costs: 920 yuan/mu, of which: electricity 150 yuan/mu; pond rent 600 yuan/mu; large fish fingerlings: 70 yuan/mu (40 tails per mu, 0·25 kg per tail); hired labor and depreciation 100 yuan/mu.
Farming Prospects for Giant River Prawns
Giant river prawns originated in tropical regions and have relatively high temperature requirements during the growth period. In the middle and lower reaches of the Yangtze River, stocking begins in May-June, and harvesting takes place in October. The market supply is relatively concentrated, and at other times giant river prawns generally cannot be eaten. In order to increase income, some places have begun using greenhouses to raise shrimp, greatly advancing the harvesting time and multiplying the benefits.
Giant river prawns are rich in nutrition, delicious in taste, large in size, and sell well on the market. Giant river prawns have omnivorous feeding habits, grow quickly, are easy to farm, and have good market prospects. They have now become one of the specially excellent aquatic products that China focuses on developing. Not only has pond farming made considerable progress, but rice-field farming has also been successful. At present, giant river prawn farming is in a stage of development, and giant river prawn farming has broad prospects.
Common Diseases of Giant River Prawns
1. Ciliate disease
A large number of ciliates (such as Vorticella, Epistylis, Zoothamnium, etc.) parasitize the body surface of diseased shrimp. The body surface appears brownish-yellow and fluffy, affecting the diseased shrimp's feeding and molting, and in severe cases can cause shrimp death. The main cause is excessively fertile water, in which Vorticella, Epistylis, Zoothamnium and others multiply in large numbers.
Prevention and control methods: change water regularly to keep the water clean; use 0.4 ml/kg bromochlorohydantoin for water disinfection; splash a mixture of copper sulfate and ferrous sulfate (5:2) at a concentration of 0.7 mg/kg.
2. Brown spot disease
The body surface of diseased shrimp has speckled yellow-brown ulcers, with the center of the ulcers sunken. They occur more often on the cephalothorax and abdomen, and sometimes also on the antennae, tail fan and other appendages, seriously affecting the shrimp's growth and molting. It is mainly caused by mechanical damage during capture and transportation.
Prevention and control methods: pay attention to handling to prevent mechanical damage to the shrimp body; splash 0.3 mg/kg Chlorine King; mix 0.5-1 g oxytetracycline per kg of feed or mix 1-2 g shrimp bran for feeding, with 5-7 days as one treatment course.
It can be seen that giant river prawns are not only rich in nutrition, but for farmers the most important thing is that their market time is concentrated and their yield is high, which can bring relatively considerable economic benefits. However, the farming industry is unlike others, so naturally the demands in terms of effort are also higher.