In order to further explore the breeding mode and culture technology of Lieopenaeus Vannamei in the Guangxi North Guangxi region, we conducted trials of freshwater pond culture of Penaeus vannamei from 2001 to 2002. The current results are based on the results of the 2002 culture experiment. The purpose is to explore and explore the culture mode and culture technology of Penaeus vannamei in freshwater ponds under environmental conditions.
I. Pond culture technology
1. The pond condition test pond was selected at Guilin Overseas Chinese Farm No. 1#, No. 2 and No. 3 ponds with an area of ​​1 mu, 4 mu and 3.6 mu respectively. The sand and mud sediments were solid and did not leak, and the length and width ratio of the pond was 2 1:1, the slope ratio is about 1:3, and the impoundment depth is 1.6m. The water source is Lijiang River water, with fresh water, no pollution, and mechanical drainage and irrigation. 1# pond is a nursery pond equipped with a 380W aerator, and 2# pond and 3# pond are each equipped with a 1.5kW aerator.
2. Preparation of shrimp before stocking (1) Clearance of the pond on April 20th 1# pond dry pond exposure 10 days, remove excess silt in the pond, on April 30 into the river water 50cm, with 60kg/mu tea bran water Quanchiposa , Clear all wild fish, on May 5 according to 1200kg / acre m release of sea salt, May 25 shrimp "test water", the survival rate is low, and on June 1 release sea crystal 100kg / acre, sea salt 50kg/mu; on June 8th, 2# pond and 3# pond dry pond 10 days later, on June 18th, water was added to the water depth of 20cm, and 50kg/mu of tea bran was sterilized. On June 28, 50kg/mu of sea salt was placed. Add water to 60cm.
(2) Shrimp seedling desalination (interimation) and test water On June 7, 0.6 million shrimp seedlings were purchased from the Guangxi Fisheries Research Institute and desalted in the 1# pond. Feed 4 times a day, mainly feeding eggs, and feed a small amount of peanut bran appropriately to cultivate water quality. After 7 days of seedlings, water was added to desalt, and the inlet was filtered with a mesh of 60 mesh. The depth of water was increased by 5cm every day for the first two days. The third day was followed by one additional day. Each time the water depth was increased by 15cm. By June 22, the water level has increased to about 1.0m. At this time, the shrimp grows to a body length of 1.0cm to 1.5cm. The feed was changed to a special feed for Penaeus vannamei, sometimes adding a little peanut bran to cultivate water quality. On June 28, shrimps grow to a body length of 2.0cm to 2.5cm. Each day, 15cm of water is pumped from 1# pond to 2# pond and 3# pond, while river water is supplemented with 30cm to 1# pond. Days, on July 1st, put 100 shrimp seedlings into the 2# pond and 3# pond nets to test the water, and the survival rate after 48 hours is 100%.
3. Shrimp seedlings separate ponds On July 3rd, shrimps from No. 1 pond were placed into No. 2 and No. 3 ponds, and the stocking density was 31,860/tail, totaling 275,200, with specifications of 2 to 3 cm. The standard survival rate was 68.8%.
4. Feeding and Management (1) Water quality regulation After the shrimp seedlings are divided, the pool water is gradually deepened to the maximum level of 1.6m in the shrimp pond within 1 month. After that, the water is changed at any time according to the water quality of the pool, the growth of the shrimp seedlings, etc., but the amount of water is changed every time. Not more than 20cm, at the same time topdressing sea salt 25kg per acre, every 2 days after the application of lime 10kg/mu, in order to maintain the shrimp pond water quality environment is relatively stable. Oxygen aeration machine is turned on at a proper time every day to control the content of physicochemical factors in the water: pH value 7.8-8.5, transparency 30cm-35cm, dissolved oxygen 5mg/L or more, ammonia nitrogen less than 0.15mg/L, and hydrogen sulfide less than 0. 1mg/L.
(2) In addition to the main stage of the feeding, the whole growing process is fed with artificial compound feed. The daily feeding amount is generally 5% to 20% of the body weight of the shrimp, and is flexibly controlled according to the quality of the pool water, the feeding of the shrimp, the growth, and the weather of the day. Close the aerator for 2 hours before and after feeding. Feeding at the same time depending on the water conditions appropriate to feed a little peanut bran.
(3) Daily management adheres to the early, middle and late afternoons. First, observe changes in water quality, determine the quality of water, and adjust water quality in a timely manner; second, check the feeding and swimming status of shrimps, determine whether there is shrimp disease, and strive to achieve early detection and early prevention of disease; and third, randomly sample every 15 days. Twenty-nine to thirty shrimp seedlings were measured biologically and the physicochemical factors were determined in order to understand the growth rate and survival rate of shrimp seedlings, and to provide basis for determining the amount of feeding and regulating water quality.
(4) Disease prevention and control The principle of “prevention from prevention and prevention from combination†is adhered to. The specific operation is as follows: Every day from 15 days to 20 days, Quanchipi throws lime 10kg/mu~15kg/mu, purifies water quality, and adjusts pH; 15 days use 0.3ppm bromochloroheine to prevent the occurrence of shrimp disease. If bacterial disease is found, use 0.4ppm bromochlorohydantoin twice or 3 times; regularly add Vc, allicin, calcium, magnesium, etc. to the feed. Minerals to enhance shrimp disease resistance and avoid or reduce shrimp disease.
Second, the results and discussion
1. Test results (1) Production September 27, 2002, a random throw net was taken for No. 2 pond, and the method for calculating yield per unit area was accepted. The results showed that the average length of white shrimp was 10.0 cm, and the average tail weight was 9.9 g. The output was 1017.6kg, with an average yield of 254.4kg per mu. The survival rate was 80.6%.
(2) Economic benefits A total of 2187.8kg of shrimps were harvested, the income was 6,1258.4 yuan, and the total expenditure was 37,656 yuan, including fees for shrimp seedlings, feed, wages, electricity, ponds, depreciation, shrimp and medicine, and net profit of 1,7502.4 yuan. The input-output ratio is 1:1.4, and the bait coefficient is 1.3.
2. Discussion (1) The impact of water quality cultivation before and after stocking on the crude survival rate of the standard: Because the clear pond time is too long, the water quality is not well controlled, and plankton is less, the larvae multiply after stocking, and compete with the shrimp seedlings. The crude seed survival rate of shrimp seedlings has a great impact, which is the main reason for the low survival rate of shrimp seedlings.
(2) Effect of feed on the growth rate of Penaeus vannamei: The quality of feed directly affects the growth rate of Penaeus vannamei. During the experiment, due to frequent feed replacement for a period of time, Penaeus vannamei grows slowly and shrimp disease resistance Poor, easy to disease. Therefore, it is suggested that choosing a nutrient-rich and relatively stable feed for shrimp during the whole breeding process is the key to success.
I. Pond culture technology
1. The pond condition test pond was selected at Guilin Overseas Chinese Farm No. 1#, No. 2 and No. 3 ponds with an area of ​​1 mu, 4 mu and 3.6 mu respectively. The sand and mud sediments were solid and did not leak, and the length and width ratio of the pond was 2 1:1, the slope ratio is about 1:3, and the impoundment depth is 1.6m. The water source is Lijiang River water, with fresh water, no pollution, and mechanical drainage and irrigation. 1# pond is a nursery pond equipped with a 380W aerator, and 2# pond and 3# pond are each equipped with a 1.5kW aerator.
2. Preparation of shrimp before stocking (1) Clearance of the pond on April 20th 1# pond dry pond exposure 10 days, remove excess silt in the pond, on April 30 into the river water 50cm, with 60kg/mu tea bran water Quanchiposa , Clear all wild fish, on May 5 according to 1200kg / acre m release of sea salt, May 25 shrimp "test water", the survival rate is low, and on June 1 release sea crystal 100kg / acre, sea salt 50kg/mu; on June 8th, 2# pond and 3# pond dry pond 10 days later, on June 18th, water was added to the water depth of 20cm, and 50kg/mu of tea bran was sterilized. On June 28, 50kg/mu of sea salt was placed. Add water to 60cm.
(2) Shrimp seedling desalination (interimation) and test water On June 7, 0.6 million shrimp seedlings were purchased from the Guangxi Fisheries Research Institute and desalted in the 1# pond. Feed 4 times a day, mainly feeding eggs, and feed a small amount of peanut bran appropriately to cultivate water quality. After 7 days of seedlings, water was added to desalt, and the inlet was filtered with a mesh of 60 mesh. The depth of water was increased by 5cm every day for the first two days. The third day was followed by one additional day. Each time the water depth was increased by 15cm. By June 22, the water level has increased to about 1.0m. At this time, the shrimp grows to a body length of 1.0cm to 1.5cm. The feed was changed to a special feed for Penaeus vannamei, sometimes adding a little peanut bran to cultivate water quality. On June 28, shrimps grow to a body length of 2.0cm to 2.5cm. Each day, 15cm of water is pumped from 1# pond to 2# pond and 3# pond, while river water is supplemented with 30cm to 1# pond. Days, on July 1st, put 100 shrimp seedlings into the 2# pond and 3# pond nets to test the water, and the survival rate after 48 hours is 100%.
3. Shrimp seedlings separate ponds On July 3rd, shrimps from No. 1 pond were placed into No. 2 and No. 3 ponds, and the stocking density was 31,860/tail, totaling 275,200, with specifications of 2 to 3 cm. The standard survival rate was 68.8%.
4. Feeding and Management (1) Water quality regulation After the shrimp seedlings are divided, the pool water is gradually deepened to the maximum level of 1.6m in the shrimp pond within 1 month. After that, the water is changed at any time according to the water quality of the pool, the growth of the shrimp seedlings, etc., but the amount of water is changed every time. Not more than 20cm, at the same time topdressing sea salt 25kg per acre, every 2 days after the application of lime 10kg/mu, in order to maintain the shrimp pond water quality environment is relatively stable. Oxygen aeration machine is turned on at a proper time every day to control the content of physicochemical factors in the water: pH value 7.8-8.5, transparency 30cm-35cm, dissolved oxygen 5mg/L or more, ammonia nitrogen less than 0.15mg/L, and hydrogen sulfide less than 0. 1mg/L.
(2) In addition to the main stage of the feeding, the whole growing process is fed with artificial compound feed. The daily feeding amount is generally 5% to 20% of the body weight of the shrimp, and is flexibly controlled according to the quality of the pool water, the feeding of the shrimp, the growth, and the weather of the day. Close the aerator for 2 hours before and after feeding. Feeding at the same time depending on the water conditions appropriate to feed a little peanut bran.
(3) Daily management adheres to the early, middle and late afternoons. First, observe changes in water quality, determine the quality of water, and adjust water quality in a timely manner; second, check the feeding and swimming status of shrimps, determine whether there is shrimp disease, and strive to achieve early detection and early prevention of disease; and third, randomly sample every 15 days. Twenty-nine to thirty shrimp seedlings were measured biologically and the physicochemical factors were determined in order to understand the growth rate and survival rate of shrimp seedlings, and to provide basis for determining the amount of feeding and regulating water quality.
(4) Disease prevention and control The principle of “prevention from prevention and prevention from combination†is adhered to. The specific operation is as follows: Every day from 15 days to 20 days, Quanchipi throws lime 10kg/mu~15kg/mu, purifies water quality, and adjusts pH; 15 days use 0.3ppm bromochloroheine to prevent the occurrence of shrimp disease. If bacterial disease is found, use 0.4ppm bromochlorohydantoin twice or 3 times; regularly add Vc, allicin, calcium, magnesium, etc. to the feed. Minerals to enhance shrimp disease resistance and avoid or reduce shrimp disease.
Second, the results and discussion
1. Test results (1) Production September 27, 2002, a random throw net was taken for No. 2 pond, and the method for calculating yield per unit area was accepted. The results showed that the average length of white shrimp was 10.0 cm, and the average tail weight was 9.9 g. The output was 1017.6kg, with an average yield of 254.4kg per mu. The survival rate was 80.6%.
(2) Economic benefits A total of 2187.8kg of shrimps were harvested, the income was 6,1258.4 yuan, and the total expenditure was 37,656 yuan, including fees for shrimp seedlings, feed, wages, electricity, ponds, depreciation, shrimp and medicine, and net profit of 1,7502.4 yuan. The input-output ratio is 1:1.4, and the bait coefficient is 1.3.
2. Discussion (1) The impact of water quality cultivation before and after stocking on the crude survival rate of the standard: Because the clear pond time is too long, the water quality is not well controlled, and plankton is less, the larvae multiply after stocking, and compete with the shrimp seedlings. The crude seed survival rate of shrimp seedlings has a great impact, which is the main reason for the low survival rate of shrimp seedlings.
(2) Effect of feed on the growth rate of Penaeus vannamei: The quality of feed directly affects the growth rate of Penaeus vannamei. During the experiment, due to frequent feed replacement for a period of time, Penaeus vannamei grows slowly and shrimp disease resistance Poor, easy to disease. Therefore, it is suggested that choosing a nutrient-rich and relatively stable feed for shrimp during the whole breeding process is the key to success.
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