In recent years, there have been feedback from South American white prawn farmers that white prawn have grown little in summer and the feed ratio is generally higher. There are some extreme examples where the feed ratio actually exceeds 1:5. On the surface, there are few common causes for the growth of Penaeus vannamei: Water temperature is an important factor in maintaining the normal feed metabolism of Penaeus vannamei. Physiological abnormalities such as the effects on digestive enzyme activity in hepatopancreas may occur in shrimp that exceeds the temperature of physiological adaptation of Penaeus vannamei. Factors affecting the water temperature in the summer: First, the water temperature is too high, there are some breeding areas, and the summer water temperature often exceeds 35°C. This water temperature may even cause abnormal phenomena such as stealing death. The way to deal with it is to change the water in the conditional culture area, reduce the water temperature as much as possible or use a awning. Second, the water temperature fluctuations day and night too much, which will lead to shrimp metabolic disorders and shrimp hepatopancreas antioxidant enzyme activity decreased. The larger the diurnal fluctuation of temperature and temperature, the more susceptible the liver of shrimp is to injury, resulting in decreased ability to resist shrimp, infection of other biological diseases and physiological metabolic disorders. Coping methods: When the wind is strong and the sun is strong, maintain an appropriate water level, fully activate the uniform water body of the aerator, and fully exert the quilt effect under the premise of maintaining the dissolved oxygen at the bottom, and fully reduce the excessive fluctuation of the water temperature. The lack of dissolved oxygen, especially the lack of dissolved oxygen at the bottom, has a greater impact on benthic shrimp. Like the metabolism of all living things, shrimp is the process of assimilation of feed protein and other nutrients into shrimp body protein. This assimilation process is an oxygen-consuming process. The level of dissolved oxygen in the water has a significant impact on the feed ratio and the growth rate of shrimp. When the dissolved oxygen in the water body is too low to meet the metabolic needs of shrimp, enzymes in the organism will be inhibited. This water condition makes it difficult for shrimp to grow at a normal rate. Deterioration at the bottom can lead to anaerobic metabolites in ponds (ammonia nitrogen, nitrite, and hydrogen sulfide build-up, etc.), dominant waterborne microorganisms, and high parasitic infection rates, which interfere with the normal growth rate of organisms (unhulled, not eaten, Empty stomach, etc.) In aquaculture, apart from water temperature and dissolved oxygen, there are many factors that affect the growth of shrimp. Congenital causes: The breeding results have been determined since the day of the seedlings injection. There is a considerable relationship between the growth rate of an organism and the weight limit and the species of the organism. Therefore, if the shrimp grows quickly, the farmers must select the appropriate seedlings under the existing breeding conditions and breeding methods. It is undeniable that there are some varieties that are indiscriminate, and indeed farmers are disappointed with the results of the breeding. This is the "iron seedlings." Poor response to the digestive system: The most common is often referred to as poor liver transfusion and liver atrophy. The hepatopancreas of shrimp is also called the midgut gland. It is an important part of the digestive system of shrimp. On the one hand, the hepatopancreas secretes digestive enzymes to digest the nutrients in the feed. On the other hand, the nutrients of the feed after digestion and decomposition in the intestine are recombined into Some of shrimp's protein and fat, glycogen, are stored in the hepatopancreas. The status of hepatopancreas is also related to the excretion of shrimp, molting cycle and involvement in hematopoiesis and ion transport. Therefore, there is a considerable relationship between whether the shrimp liver is good or not, and whether the shrimp are large or fast. pH: When this common indicator of water quality is abnormal, it will have some adverse effects on the hepatic protease and amylase, glutathione S-transferase activity and other physiological functions of shrimp. Too high and too low pH have a significant impact on the shelling and shelling recovery of shrimp, which affects the biological efficiency of feed and the growth rate of shrimp. Feed Nutrition: Studies have shown that, under starvation conditions, changes in liver and pancreas nutrients in Penaeus vannamei are a significant decrease in hepatopancreas glucose and hepatic glycogen, followed by a significant decrease in acylglycerides, and only protein levels remain Changing, that is to say, under starvation conditions, Penaeus vannamei uses protein as the main form of energy storage. With the increase of protein and quantity of normal shrimp intake, the activity of hepatopancreas pepsin was significantly enhanced, and there was no significant change in intestinal protease. This also reflected the importance of the quality and quantity of protein in the feed to hepatopancreas and other physiology of shrimp. Heavy metals (including excessive intake of trace elements): Through the analysis of well water for aquaculture such as Jiangsu Rudong and Lianyungang this year, we have seen more copper and cadmium and chromium. Copper is an essential element of the animal body. Copper is also the carrier of oxygen in the blood, such as shrimp, the central atom of hemocyanin. Therefore, the lack of copper will have a significant impact on its growth and development. When the Cu2+ concentration exceeds the body's regulation range, excessive accumulation in the body, it will cause poisoning. Cadmium is a non-essential element. When the concentration is high, the activity of antioxidant enzymes is obviously inhibited. Chromium is an exogenous pollutant, and it is one of the main heavy metal pollution elements in fishery waters. High concentration of chromium has a significant impact on the antioxidant enzyme system of shrimp. Coping methods: Choose a good source of water when building a site, and use the EDTA and Blue Fluorescent Plot to reduce the heavy metal content of the water body during the cultivation process. Ingestion of abnormal algae or abnormal organisms: Abnormalities in the liver of shrimps are currently caused by abnormal algae, which is common in freshwater aquaculture areas. Microcystis is a kind of abnormal algae, which is easy to cause “flower liverâ€. Microcystis is controlled. “Huahuagan†is naturally better. Bare algae, dinoflagellates, moss, etc. are also abnormal algae, and shrimps ingest harmful plants (moss, bad algae, etc.) that can affect nutrient absorption and liver damage (also called poisoning) of shrimp. In a pond, the first shrimp to eat abnormal algae is often the larger size shrimp in the pool, resulting in the phenomenon of shrimp growing smaller and smaller. Abnormal organisms have only emerged in recent years and have an impact on the growth of shrimp. Physiological reasons: artificially cultivated shrimp, daily intake of food more than natural, nutrient-based three major nutrients, liver essential nutrients in the digestive system may be relatively small. The general tissue cells of living organisms synthesize their own proteins, but in addition to synthesizing their own proteins, the liver also needs to be responsible for the synthesis of most of the circulatory system proteins. It is estimated that the total amount of protein synthesized by the liver accounts for more than 40% of the total amount of systemically synthesized proteins. Therefore, the artificially cultivated prawns with relatively fast growth rate can easily develop hepatopancreas if the corresponding hepatic fortification nutrient in the daily intake food of the prawns is insufficient to meet the needs of the liver, and at the same time, the full-valent nutritional natural food is not enough. Bad, once developed, it will obviously appear slower. Therefore, it is necessary to properly protect the liver during the artificial breeding process. Malnutrition or other factors cause shell change: the growth of crustaceans is a discontinuous process, and only the shellfish can grow. Therefore, shell replacement is not only a sign of developmental metamorphosis of Penaeus vannamei, but also individual growth of shrimp. One of the necessary stages. Without shell replacement, there is no growth of shrimp, that is, no shells grow longer. The process of re-shelling the shrimp includes two processes of shelling and restoring shell hardness. The expulsion stage is mainly regulated by the endocrine dehulling hormones of shrimps. To synthesize these hormones that control the shelling of shrimps, it is necessary for the shrimps to be able to obtain the nutrients of the former from the food. The shrimps can be fully synthesized. The nutrient basis for the secretion of the chitin. If these nutrients are not present in the feed, it is difficult for the shrimp to secrete sufficient amounts of dehullers to allow the shrimp to shell out in time. Malnutrition caused by bad habits in the farming process: Some farmers like to habitually feed some traditional Chinese medicines that are legendary, and habitually feed certain single nutrients or other things without reference, which interferes with the absorption of feed nutrients. The so-called malnutrition refers to nutritional imbalance, including the intake of certain nutrients is too much or too little, long-term mixed feeding of a nutrient will interfere with the absorption of other nutrients lead to other nutrients of malnutrition. Regularly fed Chinese herbal medicines also interfere with the absorption of nutrients in many feeds due to some components of the roughing process (eg, vegetable acids, etc.). Therefore, in the aquaculture production process, when people often hear that there is something miraculous about who mixes certain things every day, farmers should use their own breeding conditions and experience to go and pretend to really absorb other people's good experiences. Infected parasites also affect shrimp growth: Infected with different parasites, the symptoms are also different, may cause poor shell replacement, interfere with normal nutrient absorption or direct damage to the digestive system of the liver, intestine, etc., resulting in shrimp Growth slows. For example, in 2016, Taishan Guanghai sampled 300 mu of earthen ponds and found that most of the sediments on the surface of ponds had a weight loss rate of more than 50% after burning at 600°C. It can be imagined that these sediments have accumulated Severely, the sampled shrimp was also very seriously infected with ciliates. There are many examples of the impact of ciliates in the Pearl River Delta on the growth rate of prawns. It can also be seen from the farmers' intuition. It controls the ciliate prawn shell replacement smoothly, and the body weight quickly goes up. For the infection of parasites, prevention should be the main method. The measures should be to make the body of water and sediment not too fat and to reduce the material basis for parasite reproduction. In addition, the light intensity, nesting varieties, nesting time, breeding density and pond conditions do not match, climate factors, etc., are all factors that affect shrimp growth. We are a specialized manufacturers of Sexual Enhancement Materials from China; with advanced R & D and manufacturing in Enhance libido Materials . With high-quality products of Sex Enhance Ingredients , we can be a trust suppliers / factory. As a wholesale of Sexual Performance Imporve Material , we have the perfect after-sales service and technical support. Look forward to your cooperation! Sildenafil Citrate,Tongkat Ali Extract,Donkey-hide Glue Extract,Sex Enhance Ingredients,Sexual performance Imporve material Xi'an Quanao Biotech Co., Ltd. , https://www.quanaobiotech.com