How much is white shrimp (Litopenaeus vannamei) per jin? Detailed explanation of feeding and management key points

White shrimp (Litopenaeus vannamei) has characteristics such as strong environmental adaptability, fast growth speed, few diseases, high yield, large individual size, and excellent disease resistance. In recent years, market demand for it has gradually increased. So how much is the price of white shrimp per jin? What are the feeding and management key points?

I. How much is the price of white shrimp per jin?

In May, in the Zhanjiang area of Guangdong, the average price for the 35 head/jin specification of white shrimp was 22 yuan/jin, a month-on-month decrease of about 15.4%, and the average price for the 40 head/jin specification was 20 yuan/jin, a month-on-month decrease of about 13%; in the Pearl River Delta area of Guangdong, the average price for the 35 head/jin specification was 22 yuan/jin, a month-on-month decrease of about 21.4%, and the average price for the 40 head/jin specification was 21 yuan/jin, a month-on-month decrease of about 19.2%; in the Guangxi area, the average price for the 35 head/jin specification was 26 yuan/jin, a month-on-month decrease of about 7.1%, and the average price for the 40 head/jin specification was 22 yuan/jin, a month-on-month decrease of about 8.3%.

Although shrimp prices in China have recently rebounded, some industry insiders say that this year global white shrimp may still generally show a phenomenon of oversupply. At present, in 2019, apart from Thailand and China, other main producing areas have all actively increased white shrimp production. Among them, in the first half of this year, India's shrimp production increase pattern is highly likely to occur, and it can even be described as crazy expansion. However, affected by the 2018 China-US trade friction, downward pressure on the domestic economy has increased and consumption growth has slowed. Some industry insiders expect that in the first half of 2019, the consumption volume of imported white shrimp in the Chinese market may not show a major expansion, and the white shrimp inventory that concentratedly arrived in the Chinese market after the Spring Festival also needs time to be digested. At the same time, China's shrimp production is also expected to recover.

II. What are the feeding and management key points for white shrimp?

1. How to ensure good shrimp fry: Some shrimp farmers only consider price and do not consider or do not value the quality of shrimp fry. Knowing that the quality is poor, they only think of stocking more shrimp, not realizing that the survival rate of the fry is low and the number in the pond cannot be estimated, so how easy is it to succeed in farming?

2. When purchasing fry, it is best to choose those that are virus-free, relatively large in specification, with an average body length of more than 1 cm, strong vitality, robust body shape, complete form, no deformity, gastrointestinal tract full of food, with the body straight when swimming, able to quickly move to the side against the current when the water is stirred, able to jump forcefully, and with no parasites or attached dirt on the body surface. During the desalination process of white shrimp (salinity must not exceed one part per thousand per day).

3. View on stocking density per mu when releasing shrimp fry: When releasing shrimp fry, it is necessary to base it on the pond water depth and the amount of water stored according to local water source conditions. Under normal circumstances, when the water depth is 12—14 m, release 250,000—300,000 fry/mu. At 15—16 m depth, 350,000—400,000 fry; at 17—18 m, about 450,000—550,000 fry; for shrimp ponds above 19 m, even at most no more than 80,000 fry per mu. Calculate the area and the number of fry to be released well, put in the same batch of shrimp fry, and release enough in one go.

4. To raise shrimp, first raise the water: Before releasing the fry, first fertilize the water well so that after the shrimp fry are released into the pond there is sufficient bait. This is because young shrimp mainly feed on plankton in the water. During the water fertilization process, organic fertilizer can be used together with some inorganic fertilizer (chemical fertilizer), or some special aquatic water-fertilizing agents can be used together with photosynthetic bacteria. This can effectively absorb the ammonia produced during the water fertilization process. To prevent water quality deterioration, if photosynthetic bacteria are not added during the water fertilization process, the ammonia in the water will increase, affecting the antibacterial ability and survival rate of the shrimp fry. When young shrimp are 2—4 cm in body length, the plankton in the pond water is completely unable to meet the feeding needs of the shrimp. At this time, nutrients must be supplemented. Add LAPP high-efficiency nutrients, fish and shrimp strengthening elements, multiple vitamins, immune polysaccharides, etc. to the feed to improve the immunity of the shrimp, strengthen the physique, and lay a good foundation for success.

5. Scientific feeding: Healthy farming must have efficient and high-quality compound feed. Choose good feed and also achieve reasonable feeding. Let the shrimp eat enough and eat well without causing waste. If too much feed is added, it will spoil the water quality and bottom quality, directly affecting the healthy growth of the shrimp and also increasing farming costs. If too little feed is added, the shrimp growth cycle will be long, and farming risks will also increase. Even if the daily feeding amount is accurate, the proportion of feeding time for each meal throughout the day must also be reasonable, so that the shrimp can grow healthily, farming costs can be reduced, and the feed conversion ratio can also be lowered. White shrimp have a relatively large food intake. In high-level ponds with water temperature at 23°C—32°C, feed is generally divided into 4—5 times, following the principle of feeding less and more frequently. The feeding amount at night accounts for 70%—80% of the whole day, and the daytime accounts for 20%—30%. The specific feeding times are: at 18—19 in the afternoon, feed 35% of the whole day; at 23 o'clock, 15%; at 4:30, 25%; at 10:30, 15%; at about 14:30, 10%. Every 5 mu should have two net cages of about 0.8 sq m set up to check the shrimp's feeding situation. When feeding, the feed in the net cage should account for about 1% of the total feed amount in the net cage. Checking the feeding time of shrimp in the net cage should be determined according to different growth stages of the shrimp. Before the shrimp body length reaches 8 cm, that is, around 45 days, the feeding time should be controlled at about 2 hours and 30 minutes. In the middle and late growth stages when the shrimp body length is 9 cm, it is better to control the feeding time so they finish eating in 1 hour—1 hour 30 minutes. If the eating time is long, then feed should be reduced; if the eating time is short, then feed should be increased.

6. Improvement of bottom quality: In the middle and late stages of white shrimp farming, good work should be done to improve the water environment and bottom quality. Due to high-density rearing, the amount of feed also increases accordingly. Residual feed at the pond bottom and aquatic animal excrement and other organic matter settle, are transformed by bacteria and other organisms, rot and decompose, consume large amounts of dissolved oxygen, and produce large amounts of ammonia oxygen, nitrite nitrogen, and hydrogen sulfide. It is necessary to reduce the eutrophication of the water body and inhibit the growth of pathogenic bacteria and harmful algae. To achieve the natural ecological balance of the farming water body, it is necessary to start by controlling feed and reducing feed, feeding about 70% of the usual feed amount, promptly enhancing sewage discharge, strengthening water intake and drainage, or regularly using bottom quality improvement drugs. Commonly used drugs include: zeolite powder (non-drug), live water element (non-drug), Western non-benefit, photosynthetic bacteria, EM and other products, any 1—2 kinds can be selected for use, so that the sediment at the pond bottom is fully oxidized and decomposed. When the pond water returns to normal, then gradually increase the feed to the normal level.