The early culture of Penaeus vannamei is affected by various factors, and the incidence rate is high. Early breeding in recent years has not been very successful. In 2005, in Hainan Province, South American white prawn had 60 to 70% of the row of ponds, causing huge losses. Objectively, it is affected by factors such as climate and seedlings, subjectively requiring managers to further strengthen their management in breeding. For this reason, the author combines the management experience in the actual operation of aquaculture production in recent years and discusses several points of view.
First, the overall idea 1, make a good production plan to ensure that there are enough seedlings pond. Based on the stocking area, stocking density, and expected discharge specifications, the number of seedlings should be calculated, and the early rough management should be conducted. Roughing culture, on the one hand, is easy to manage, and on the other hand it can make the rearing pool have a longer time to rest and save time. The more important for the quality of the current shrimp seedlings is to eliminate weak seedlings, and the elimination ratio can reach 20-30%. Accordingly, the overall seedling survival rate is only about 60%. If the plan is to harvest 50 shrimp per jin, the yield per mu is 1000 jin, and the seedling amount is at least 6 to 70,000 tails per mu, and the seedling volume is at least It is 1-10 thousand/mu. Shrimp should adhere to fixed-point production, choose a seed enterprise with good reputation and strength, and control the whole planting field to cooperate in the production of high-quality shrimp seedlings instead of blindly looking for seedlings. Ensure the health of the seed.
2, aquaculture cost management. The current market price of shrimp, to be profitable, depends on controlling the cost of farming and creating an absolute competitive advantage relative to low cost. The existing high-level pool culture model has a direct cost that can be basically controlled at about 6 yuan/kg, analyzes the data collected over the years, early-generation profits and feed coefficients, the percentage of feed costs (the percentage of feed in the cost), and the breeding cycle. There was a significant relationship between the cost of the shrimp and the selling price. The feed coefficient, the percentage of the feed cost and the breeding cycle were directly related to the cost. The level of feed coefficient reflects the conversion rate and utilization rate of feed. The percentage of feed cost reflects the level of its technical management. Therefore, the main factor determining the cost per kilogram of shrimp is the comprehensive performance of technical control ability and technical management level. The basic technical indicators of its profit and loss critical point are: 700 kg per mu; feed coefficient 1.5; Jinsu cost 7.5 yuan/kg; feed cost percentage 55%; breeding cycle (after seedling) 90 days.
3, according to the market adjustment of farming ideas. For early-breeding, it is generally believed that large-sized shrimp should be raised, but large-sized shrimps are difficult to raise due to the influence of seedlings and market demand, and shrimps can still be sold as live shrimp for the medium-sized shrimps before the end of June, and prices are still good. The breeding period is not too long, which requires that the seedling quantity is slightly higher when the seedlings are released, ensure that the size of the seedlings is 50 heads/jin, and the yield per mu is not less than 1,000 kg, so the profit will be better.
two. Technical links
1, pre-management of seedlings. Early shrimp farming, the weather is changeable, the impact of cold air occurs from time to time, the temperature fluctuations are large, the amount of shrimp ponds affected by temperature is relatively large, but also affect the pool of stocking density. Therefore, the management of early seedlings is particularly important. Firstly, the shrimp cultures in the standard crude pool reach a depth of about 5cm after 45 days or so, and are then divided into culture ponds. This has great significance for improving the survival rate and preventing diseases. Secondly, feeding ample and high-quality feed, and at the same time During the period of easy onset, nutrition is strengthened, and VC, VE, polysaccharides and other nutrients are added. Shi Zengqiang’s prawn constitution improves disease resistance and stress; once again, seedlings are divided at the right time to ensure even and uniform seedlings. After 30-40 days of concentrated feed in the holding pond, the shrimp seedlings begin to show a certain degree of differentiation. Different meshes can be used to screen seedlings of different specifications to different pools. Try to ensure that the shrimps in each pool are basically the same size and convenient. Develop management.
2, do a good job of preventing diseases. The incidence of early-stage shrimp aquaculture has been higher than that of late-breaking crops over the years, and disease prevention is particularly important. Its precautions are:
(1) Anti-pathogenic pathogen infection. To prevent infection, the first is to prevent the invasion of all pathogens, that is, to adopt pond disinfection, water disinfection, the use of non-specific pathogens and non-toxic shrimp and other methods. We believe this method is unsuitable for conventional shrimp farming, because the largest viruses that endanger shrimps have long existed in ponds, water sources, and even shrimp. The second is to prevent the pathogenicity of pathogenic infection, that is, the onset of the season or the surrounding pond has been the disease, to prevent the exchange of water, cross-use tools, etc. to bring into the pathogenesis of a strong pathogen, which should be the focus of anti-infection.
(2) reduce the predisposing factors. Caused by the shrimp virus disease induced factors are: 1 "water changes." A variety of reasons, such as abrupt changes in weather, algae aging, medication, and water changes, will all reduce shrimp resistance. Sometimes several causes occur at the same time or alternately, and it is more likely to cause illnesses. For example, sudden changes in the weather after changing the water, mistakes in the use of zeolite powder-based bottom reforms, and the like can easily lead to disease. 2 inappropriate medication. All kinds of drugs have certain side effects, improper use of drugs will induce disease. 3 points when the pool is not operating properly. Split seedlings and ponds should be selected as far as possible when the weather is good. When the physical and chemical indicators of the two pools are basically the same, they are operated to avoid severe stress after the pool, and the shrimp does not eat material to cause the disease.
(3) Improve shrimp body resistance. Prawn living in the bottom, the environment is poor; the growing process continues to shell, the body is weak, so shrimp is more susceptible than fish, and once the shrimp onset, it is difficult to cure. In addition, ecologically cultivated shrimp, drugs are easy to damage the water quality, and the use of drugs is more harmful. Therefore, it is more important to improve the disease resistance of shrimps. The basic measures are: 1 Select healthy seedlings. 2 strengthen nutrition. Malnutrition is an important source of morbidity. Almost all diseases are related to nutrition. Feed a nutritious diet, supplement vitamins and other nutrients properly, prevent overfeeding, avoid chronic enteritis, and increase nutrient uptake. 3 reduce stress factors. Maintain water quality, avoid blind medication, and ensure the continuity and stability of technical measures in the breeding process. 4 administered antiviral immune-modulating drugs. 5 Prevent the administration of any drugs (such as antibiotics, etc.) that damage the microecology and body resistance in the body.
(4) Seize the opportunity to treat early. Normal shrimp disease is not a sudden onset, and there is a staging phase between the beginning of the body and the pathogen. For an individual, that is, the incubation period. For groups, it is often the beginning of death, the "early period" stage, which is the most favorable period for treatment. Shrimp disease is difficult to treat, as long as the rules of the disease are respected, and the use of drugs is flexible, the loss of shrimp disease can be reduced to a minimum.
(5) Prevent concurrent and secondary infections. According to the survey, more than 30% of deaths caused by shrimp virus disease are caused by concurrent or secondary bacterial infections. Therefore preventing bacterial infection is another way to increase the success rate of treatment. In particular, prevention of secondary infection at the late onset stage should be the main treatment.
(6) Rational and correct use of drugs. Drugs are all irritating. General drugs do not stimulate the healthy shrimps, but they all have strong stimulation to the shrimps, which often leads to the phenomenon of accelerated death. Therefore, small-stimulation, non-residue drugs should be selected to prevent diseases. The measures include: 1 using "ecological" disinfectants instead of conventional disinfectants; 2 using degradative substratum modifiers instead of adsorptive substratum modifiers; 3 not using antibiotics to prevent disease; 4 flexible use of oxygenating agents.
3. Proper use of microbial preparations (1) Proper use of microbial preparations. In the production of microbiological agents often have too high or wrong understanding, such as: use of microbial agents can not or will not be sick; use of microbial agents can prevent viral infections; use of microbial agents will kill algae; with microbial preparations are ecological breeding ... ... In fact, this is not the case. Microbiological preparations are only for the cultivation of good microbial algae, so as to improve the culture environment, thereby enhancing the health of the shrimp body and competing with pathogenic microorganisms to achieve the purpose of disease prevention. Improper use may sometimes worsen the problem. If the dissolved oxygen is used at a low level, it will cause shrimp floating heads, swimming ponds or aggravate death. This is a common phenomenon. Microbial preparations can be used as follows: 1 Reduce water, ammonia, nitrous acid, hydrogen sulfide and other harmful substances, there is a "clean water effect", with microbial agents containing nitrifying bacteria, photosynthetic bacteria-based microbial effect is obvious. 2 Accelerate the decomposition of organic matter, promote the reproduction of algae, and have a “fat and water effectâ€. The effect of microbial preparations containing Bacillus, Lactobacillus, and yeast is obvious. 3 inhibition of harmful bacteria, play a role in disease prevention, such as containing lactic acid bacteria, Streptococcus microbial preparations. 4 Speed ​​up the purification of water bodies, promote material circulation, and mainly play a role in stabilizing water. At the same time, low-concentration “fat water†and high-concentration “clean water†are mainly compound bacteria. In addition, the growth and reproduction of microbial agents require certain conditions, such as dissolved oxygen, light, certain carriers, etc., and their use effects are also different under different conditions.
(2) Keep water quality stable. Shrimp is sensitive to changes in the environment, so to do: 1 as far as possible not to irrigate, frequently blindly use disinfectants, especially after onset, as much as possible without changing the water, disinfectant under the disinfectant, to prevent the abnormal oyster shell And stimulation, increase the pressure on the shrimp body in the environment. 2 Maintain an appropriate water level. Water is too deep, easy to lack of oxygen; too shallow, not easy to stabilize, generally about 1.2 to 1.3 meters is more appropriate. 3 sufficient oxygen, improve the ability of water oxidation. Adequate oxygen is necessary for stable water quality and rapid growth of shrimp. Rich in dissolved oxygen, all kinds of organisms can survive, the buffer system in water and other carbonates can be stable, the oxidation-reduction potential is high, and the harmful reducing substances in water, such as ammonia, nitrous acid and hydrogen sulfide, can be reduced, and shrimps can increase their feeding capacity. Increased digestibility, high energy metabolism, and inhibition of pathogenic bacteria (such as common Aeromonas) reproduction. Therefore, the creation of a three-dimensional aerobic mode and the occasional use of liquid and solid oxygenation agents to maintain adequate oxygenation are beneficial to the healthy growth of shrimp. 4 Reasonably feed and prevent bottom odor. Too much feeding, low utilization of shrimp, there are a lot of residual baits or fecal residue in the bottom, easy to smell. Shrimp lives on the bottom, and the quality of the sediment directly affects the stability of the water body and the growth and disease resistance of the shrimp.
4, timely shrimp. Timely harvest is an important factor in the high yield and harvest of shrimp culture. Harvest time should be based on market demand, value laws and shrimp growth, health status, water temperature changes, water quality and sediment pollution, food and other considerations, timely shrimp.
First, the overall idea 1, make a good production plan to ensure that there are enough seedlings pond. Based on the stocking area, stocking density, and expected discharge specifications, the number of seedlings should be calculated, and the early rough management should be conducted. Roughing culture, on the one hand, is easy to manage, and on the other hand it can make the rearing pool have a longer time to rest and save time. The more important for the quality of the current shrimp seedlings is to eliminate weak seedlings, and the elimination ratio can reach 20-30%. Accordingly, the overall seedling survival rate is only about 60%. If the plan is to harvest 50 shrimp per jin, the yield per mu is 1000 jin, and the seedling amount is at least 6 to 70,000 tails per mu, and the seedling volume is at least It is 1-10 thousand/mu. Shrimp should adhere to fixed-point production, choose a seed enterprise with good reputation and strength, and control the whole planting field to cooperate in the production of high-quality shrimp seedlings instead of blindly looking for seedlings. Ensure the health of the seed.
2, aquaculture cost management. The current market price of shrimp, to be profitable, depends on controlling the cost of farming and creating an absolute competitive advantage relative to low cost. The existing high-level pool culture model has a direct cost that can be basically controlled at about 6 yuan/kg, analyzes the data collected over the years, early-generation profits and feed coefficients, the percentage of feed costs (the percentage of feed in the cost), and the breeding cycle. There was a significant relationship between the cost of the shrimp and the selling price. The feed coefficient, the percentage of the feed cost and the breeding cycle were directly related to the cost. The level of feed coefficient reflects the conversion rate and utilization rate of feed. The percentage of feed cost reflects the level of its technical management. Therefore, the main factor determining the cost per kilogram of shrimp is the comprehensive performance of technical control ability and technical management level. The basic technical indicators of its profit and loss critical point are: 700 kg per mu; feed coefficient 1.5; Jinsu cost 7.5 yuan/kg; feed cost percentage 55%; breeding cycle (after seedling) 90 days.
3, according to the market adjustment of farming ideas. For early-breeding, it is generally believed that large-sized shrimp should be raised, but large-sized shrimps are difficult to raise due to the influence of seedlings and market demand, and shrimps can still be sold as live shrimp for the medium-sized shrimps before the end of June, and prices are still good. The breeding period is not too long, which requires that the seedling quantity is slightly higher when the seedlings are released, ensure that the size of the seedlings is 50 heads/jin, and the yield per mu is not less than 1,000 kg, so the profit will be better.
two. Technical links
1, pre-management of seedlings. Early shrimp farming, the weather is changeable, the impact of cold air occurs from time to time, the temperature fluctuations are large, the amount of shrimp ponds affected by temperature is relatively large, but also affect the pool of stocking density. Therefore, the management of early seedlings is particularly important. Firstly, the shrimp cultures in the standard crude pool reach a depth of about 5cm after 45 days or so, and are then divided into culture ponds. This has great significance for improving the survival rate and preventing diseases. Secondly, feeding ample and high-quality feed, and at the same time During the period of easy onset, nutrition is strengthened, and VC, VE, polysaccharides and other nutrients are added. Shi Zengqiang’s prawn constitution improves disease resistance and stress; once again, seedlings are divided at the right time to ensure even and uniform seedlings. After 30-40 days of concentrated feed in the holding pond, the shrimp seedlings begin to show a certain degree of differentiation. Different meshes can be used to screen seedlings of different specifications to different pools. Try to ensure that the shrimps in each pool are basically the same size and convenient. Develop management.
2, do a good job of preventing diseases. The incidence of early-stage shrimp aquaculture has been higher than that of late-breaking crops over the years, and disease prevention is particularly important. Its precautions are:
(1) Anti-pathogenic pathogen infection. To prevent infection, the first is to prevent the invasion of all pathogens, that is, to adopt pond disinfection, water disinfection, the use of non-specific pathogens and non-toxic shrimp and other methods. We believe this method is unsuitable for conventional shrimp farming, because the largest viruses that endanger shrimps have long existed in ponds, water sources, and even shrimp. The second is to prevent the pathogenicity of pathogenic infection, that is, the onset of the season or the surrounding pond has been the disease, to prevent the exchange of water, cross-use tools, etc. to bring into the pathogenesis of a strong pathogen, which should be the focus of anti-infection.
(2) reduce the predisposing factors. Caused by the shrimp virus disease induced factors are: 1 "water changes." A variety of reasons, such as abrupt changes in weather, algae aging, medication, and water changes, will all reduce shrimp resistance. Sometimes several causes occur at the same time or alternately, and it is more likely to cause illnesses. For example, sudden changes in the weather after changing the water, mistakes in the use of zeolite powder-based bottom reforms, and the like can easily lead to disease. 2 inappropriate medication. All kinds of drugs have certain side effects, improper use of drugs will induce disease. 3 points when the pool is not operating properly. Split seedlings and ponds should be selected as far as possible when the weather is good. When the physical and chemical indicators of the two pools are basically the same, they are operated to avoid severe stress after the pool, and the shrimp does not eat material to cause the disease.
(3) Improve shrimp body resistance. Prawn living in the bottom, the environment is poor; the growing process continues to shell, the body is weak, so shrimp is more susceptible than fish, and once the shrimp onset, it is difficult to cure. In addition, ecologically cultivated shrimp, drugs are easy to damage the water quality, and the use of drugs is more harmful. Therefore, it is more important to improve the disease resistance of shrimps. The basic measures are: 1 Select healthy seedlings. 2 strengthen nutrition. Malnutrition is an important source of morbidity. Almost all diseases are related to nutrition. Feed a nutritious diet, supplement vitamins and other nutrients properly, prevent overfeeding, avoid chronic enteritis, and increase nutrient uptake. 3 reduce stress factors. Maintain water quality, avoid blind medication, and ensure the continuity and stability of technical measures in the breeding process. 4 administered antiviral immune-modulating drugs. 5 Prevent the administration of any drugs (such as antibiotics, etc.) that damage the microecology and body resistance in the body.
(4) Seize the opportunity to treat early. Normal shrimp disease is not a sudden onset, and there is a staging phase between the beginning of the body and the pathogen. For an individual, that is, the incubation period. For groups, it is often the beginning of death, the "early period" stage, which is the most favorable period for treatment. Shrimp disease is difficult to treat, as long as the rules of the disease are respected, and the use of drugs is flexible, the loss of shrimp disease can be reduced to a minimum.
(5) Prevent concurrent and secondary infections. According to the survey, more than 30% of deaths caused by shrimp virus disease are caused by concurrent or secondary bacterial infections. Therefore preventing bacterial infection is another way to increase the success rate of treatment. In particular, prevention of secondary infection at the late onset stage should be the main treatment.
(6) Rational and correct use of drugs. Drugs are all irritating. General drugs do not stimulate the healthy shrimps, but they all have strong stimulation to the shrimps, which often leads to the phenomenon of accelerated death. Therefore, small-stimulation, non-residue drugs should be selected to prevent diseases. The measures include: 1 using "ecological" disinfectants instead of conventional disinfectants; 2 using degradative substratum modifiers instead of adsorptive substratum modifiers; 3 not using antibiotics to prevent disease; 4 flexible use of oxygenating agents.
3. Proper use of microbial preparations (1) Proper use of microbial preparations. In the production of microbiological agents often have too high or wrong understanding, such as: use of microbial agents can not or will not be sick; use of microbial agents can prevent viral infections; use of microbial agents will kill algae; with microbial preparations are ecological breeding ... ... In fact, this is not the case. Microbiological preparations are only for the cultivation of good microbial algae, so as to improve the culture environment, thereby enhancing the health of the shrimp body and competing with pathogenic microorganisms to achieve the purpose of disease prevention. Improper use may sometimes worsen the problem. If the dissolved oxygen is used at a low level, it will cause shrimp floating heads, swimming ponds or aggravate death. This is a common phenomenon. Microbial preparations can be used as follows: 1 Reduce water, ammonia, nitrous acid, hydrogen sulfide and other harmful substances, there is a "clean water effect", with microbial agents containing nitrifying bacteria, photosynthetic bacteria-based microbial effect is obvious. 2 Accelerate the decomposition of organic matter, promote the reproduction of algae, and have a “fat and water effectâ€. The effect of microbial preparations containing Bacillus, Lactobacillus, and yeast is obvious. 3 inhibition of harmful bacteria, play a role in disease prevention, such as containing lactic acid bacteria, Streptococcus microbial preparations. 4 Speed ​​up the purification of water bodies, promote material circulation, and mainly play a role in stabilizing water. At the same time, low-concentration “fat water†and high-concentration “clean water†are mainly compound bacteria. In addition, the growth and reproduction of microbial agents require certain conditions, such as dissolved oxygen, light, certain carriers, etc., and their use effects are also different under different conditions.
(2) Keep water quality stable. Shrimp is sensitive to changes in the environment, so to do: 1 as far as possible not to irrigate, frequently blindly use disinfectants, especially after onset, as much as possible without changing the water, disinfectant under the disinfectant, to prevent the abnormal oyster shell And stimulation, increase the pressure on the shrimp body in the environment. 2 Maintain an appropriate water level. Water is too deep, easy to lack of oxygen; too shallow, not easy to stabilize, generally about 1.2 to 1.3 meters is more appropriate. 3 sufficient oxygen, improve the ability of water oxidation. Adequate oxygen is necessary for stable water quality and rapid growth of shrimp. Rich in dissolved oxygen, all kinds of organisms can survive, the buffer system in water and other carbonates can be stable, the oxidation-reduction potential is high, and the harmful reducing substances in water, such as ammonia, nitrous acid and hydrogen sulfide, can be reduced, and shrimps can increase their feeding capacity. Increased digestibility, high energy metabolism, and inhibition of pathogenic bacteria (such as common Aeromonas) reproduction. Therefore, the creation of a three-dimensional aerobic mode and the occasional use of liquid and solid oxygenation agents to maintain adequate oxygenation are beneficial to the healthy growth of shrimp. 4 Reasonably feed and prevent bottom odor. Too much feeding, low utilization of shrimp, there are a lot of residual baits or fecal residue in the bottom, easy to smell. Shrimp lives on the bottom, and the quality of the sediment directly affects the stability of the water body and the growth and disease resistance of the shrimp.
4, timely shrimp. Timely harvest is an important factor in the high yield and harvest of shrimp culture. Harvest time should be based on market demand, value laws and shrimp growth, health status, water temperature changes, water quality and sediment pollution, food and other considerations, timely shrimp.
We can manufacture the products as clients need. PP (polypropylene) is a useful plastic and is widely used in many aspects in our daily life. Our products can be used for injection grade products, such as PP joint for transfusion bag , Pp Cap for medical container etc. More details, pls contat us as soon as possible. We are looking forward to cooperate with you and wish offer the best products to you.
Pp Resin,High Gloss Pp Resin,Polypropylene Pp Resin,Pp Homopolymer Resin
SUZHOU CRH PHARMACEUTICAL TECHNOLOGY CO.,LTD , http://www.crh-health.com