Method for food conversion of silurus meridionalis fries

Abstract

The invention provides a method for food conversion of silurus meridionalis fries, and belongs to the technical field of food conversion of silurus meridionalis fries. According to the feed conversion method for the silurus meridionalis offspring seeds, in the offspring seed feed conversion stage, the tubificidae is firstly fed to open mouths, then the pork liver is fed for offspring seed breeding, then the pork liver and silurus meridionalis offspring seed powder in different proportions are used for preparing feed conversion feed for feeding, and the offspring seeds smoothly eat artificial compound feed through 25-36-day step-by-step feed conversion, so that the yield of the offspring seeds is improved. The specification of the larvae grows from the initial 0.5-1.7 g / larvae to 7-12 g / larvae, the larvae are fed, and the larvae feeding conversion survival rate can reach 89.5% or above. Meanwhile, screening and fish separation are conducted once every 6-9 days in the food conversion breeding process, the fries are separated into different specifications to be bred, and the situation that the fries kill one another due to large specification difference is effectively prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of converting catfish fry into food, and in particular relates to a method for converting catfish fry into food. Background Art

[0002] The bigmouth catfish is a fish of the genus Siluridae of the family Siluriformes, also known as the southern bigmouth catfish, river catfish, fork-mouthed catfish, and catfish barang, etc. It is a large economic fish distributed in the main stream, tributaries and affiliated lakes of the Yangtze River Basin in China. It likes to live in open water bodies, lives a bottom-dwelling life, and is carnivorous. Under natural conditions, the fry mainly feed on rotifers, water fleas, water earthworms and other types of fry, while the fingerlings and adult fish feed on bottom fish. Under artificial breeding conditions, the fry are mainly fed with high-protein compound feed after being converted to food. The bigmouth catfish is not only large in size and grows fast, but also rich in nutrition, tender in meat, delicious in taste, and has no intramuscular spines, which is deeply loved by consumers. Due to the advantages of strong adaptability, good meat quality, high yield, and short breeding cycle, the breeding industry of bigmouth catfish has developed rapidly in recent years.

[0003] In the natural environment, catfish fry initially feed on plankton, aquatic insect larvae, etc. As they grow and develop, their food types and habits need to change. Under artificial breeding conditions, how to smoothly guide the seedlings to transition from natural bait to artificial feed is an important challenge faced in the breeding process. The purpose of feeding catfish seedlings is to improve the survival rate of seedlings by feeding them suitable biological baits and adopting scientific management methods, so that the seedlings can completely eat artificial compound feeds. At present, there are many problems with the traditional feeding method of catfish seedlings. On the one hand, some farmers rely on fresh-frozen fish as a transition bait. However, the source of fresh-frozen fish is unstable, greatly affected by factors such as seasons, regions and markets, and the price fluctuates significantly, which increases the uncertainty of breeding costs. At the same time, the storage and feeding process of fresh-frozen fish is relatively cumbersome, which can easily cause water pollution, and then cause diseases, threatening the healthy growth of catfish seedlings. For example, in hot seasons, if fresh-frozen fish is not handled properly and in a timely manner, it is very easy to deteriorate, resulting in an increase in the content of harmful substances such as ammonia nitrogen and nitrite in the water, which greatly increases the risk of disease in catfish seedlings. On the other hand, some farmers have tried to use soft pellet feed, but soft pellet feed needs to be made and fed immediately, which consumes a lot of manpower and time, and is difficult to promote and apply on a large scale. In addition, when switching to floating feed, because catfish are afraid of light, floating feed floats on the water surface, and catfish have poor feeding effect during the day, resulting in a small daily total food intake and slow growth, making it difficult to achieve the expected breeding effect. Although there are methods for feeding catfish seedlings with water earthworms as the main food, there is no scientific and reasonable food conversion method, and the survival rate of seedlings is low. In addition, water earthworms, as a high-protein natural bait, can promote the growth and development of seedlings, but there are also some potential disadvantages: 1. Risk of pathogens and parasites: Water earthworms, as live bait, may carry pathogens or parasites. If they are not thoroughly disinfected and directly used to feed fish, the risk of fish disease may increase; 2. Nutritional problems: If only water earthworms are fed for a long time, it may cause malnutrition of fish, because although water earthworms are rich in nutrients, their nutrients are relatively single and lack other nutrients required by fish; 3. Water quality problems: If water earthworms are improperly fed or overfed, their excrement and residual bait may pollute the water quality and affect the health of fish. If water earthworms die after feeding, the water quality will also be deteriorated faster; 4. Digestion problems: For some fish with poor digestive systems, fish feces with red worm skins and impurities may be discharged after feeding water earthworms, and the absorption effect is not good. Therefore, it is of great practical significance and market demand to overcome the shortcomings of existing methods for converting catfish seedlings to food, achieve efficient and stable conversion of catfish seedlings to food, improve the survival rate and economic benefits of aquaculture, and develop a scientific and reasonable method for converting catfish seedlings to food. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a method for converting catfish fry into food, which can significantly improve the survival rate of catfish fry converted into food. After 25 to 36 days of conversion breeding, the survival rate of the fry converted into food can reach more than 89.5%.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a method for converting catfish seedlings into food, comprising the following steps: firstly feeding water earthworms to open the seedlings, then feeding pig liver to cultivate the seedlings, and then feeding conversion feed 1, conversion feed 2, conversion feed 3 and conversion feed 4 in sequence;

[0007] The transition feed 1 is composed of 35% to 45% catfish seed powder and 55% to 65% pig liver;

[0008] The transition feed 2 is composed of 55% to 70% catfish seed powder and 30% to 45% pig liver;

[0009] The transition feed 3 is composed of 55% to 70% catfish seed powder, 15% to 20% pig liver and 10% to 30% water;

[0010] The transition feed 4 is composed of 75% to 85% catfish seed powder, 5% to 10% pig liver and 5% to 20% water;

[0011] The protein content of the catfish fry powder is more than 42%.

[0012] Preferably, the specification of the largemouth catfish fry is 0.5g / tail to 1.7g / tail.

[0013] Preferably, the feeding time of water earthworms to the seedlings is 6 to 9 days; the weight of water earthworms fed every day is 35% to 65% of the fish body weight.

[0014] Preferably, the time for feeding pig liver for seedling cultivation is 6 to 9 days; the weight of pig liver fed every day is 20% to 30% of the fish body weight.

[0015] Preferably, the time for feeding the converted feed 1 is 2 to 3 days, the time for feeding the converted feed 2 is 3 to 4 days, the time for feeding the converted feed 3 is 3 to 5 days, and the time for feeding the converted feed 4 is 5 to 6 days.

[0016] Preferably, the weight of the converted feed 1, the converted feed 2, the converted feed 3 or the converted feed 4 fed daily is 10% to 15% of the fish body weight.

[0017] Preferably, the method further comprises the step of screening the fish once every 6 to 9 days.

[0018] Preferably, the fry on the sieve are fed in the next step, and the fry under the sieve are fed by repeating the previous step until the fry can remain on the sieve; when the fry body length is less than 3.3cm, use the 8-day sieve; when the fry body length is greater than 3.3cm and less than 4.6cm, use the 9-day sieve; when the fry body length is greater than 4.6cm and less than 5.9cm, use the 10-day sieve; when the fry body length is greater than 5.9cm and less than 7.9cm, use the 11-day sieve; when the fry body length is greater than 7.9cm and less than 10cm, use the 12-day sieve.

[0019] Preferably, after the feeding of the transition feed 4 is completed, the catfish is completely fed with a pelleted compound feed.

[0020] Preferably, the particle size of the catfish pellet feed is 1.0 mm to 2.0 mm, and the protein content of the catfish pellet feed is above 42%.

[0021] Beneficial effects of the present invention:

[0022] The method for converting catfish seedlings to food provided by the invention comprises the following steps: firstly feeding water earthworms to cause them to open, then feeding pig liver to cultivate the seedlings, and then preparing conversion feeds with pig liver and catfish seedling powder in different proportions for feeding, and through 25 to 36 days of step-by-step conversion, the seedlings can smoothly ingest artificial compound feeds, the seedling specifications increase from the initial 0.5 g / tail to 1.7 g / tail to 7 g / tail to 12 g / tail, the conversion of catfish seedlings is completed, and the survival rate of the seedlings can reach more than 89.5%.

[0023] Meanwhile, the method of the present invention screens the fish once every 6 to 9 days during the feeding process, and separates the seedlings into different specifications for feeding, thereby effectively preventing cannibalism caused by large differences in specifications. DETAILED DESCRIPTION

[0024] The invention provides a method for converting catfish seedlings into food, comprising the following steps: firstly feeding water earthworms to open the seedlings, then feeding pig liver to cultivate the seedlings, and then feeding conversion feed 1, conversion feed 2, conversion feed 3 and conversion feed 4 in sequence;

[0025] The transition feed 1 is composed of 35% to 45% catfish seed powder and 55% to 65% pig liver;

[0026] The transition feed 2 is composed of 55% to 70% catfish seed powder and 30% to 45% pig liver;

[0027] The transition feed 3 is composed of 55% to 70% catfish seed powder, 15% to 20% pig liver and 10% to 30% water;

[0028] The transition feed 4 is composed of 75% to 85% catfish seed powder, 5% to 10% pig liver and 5% to 20% water;

[0029] The protein content of the catfish fry powder is more than 42%.

[0030] The present invention does not specifically limit the specific sources of water earthworms and pig livers, and conventional commercial products in the field can be used. In the present invention, the water earthworms are preferably fresh water earthworms, which are temporarily kept in a pool to maintain slow-flowing water and provide oxygen; the pig liver can be frozen in a freezer for standby use. In the present invention, the composition of the catfish seed powder is preferably 40% to 50% fish meal, 20% to 22% soybean meal, 5% fish oil, 6% to 8% chicken meal, 8% to 10% wheat flour, 1.5% vitamin premix, 3% yeast powder, 2% to 3% mineral premix, and 1.5% to 2% calcium dihydrogen phosphate. The catfish seed conversion method of the present invention can be carried out in a breeding workshop or in a cement pool in a heat-insulating greenhouse, and the water temperature can be maintained at 21°C to 25°C. The specifications of the catfish seed are preferably 0.5g / tail to 1.7g / tail, more preferably 0.6g / tail to 1.5g / tail, and the catfish seed is preferably a seed with neat specifications and no injuries. After the seedlings are placed in the pond, they are preferably disinfected. The disinfection preparation is preferably an iodine preparation, and the specification of the iodine preparation is preferably 0.5g / m 3 .

[0031] In the present invention, the time for feeding water earthworms to open the seedlings is preferably 6 to 9 days, and 6, 7, 8 and 9 days can be selected. The water earthworms are preferably disinfected before feeding, and the disinfection method is preferably soaking in salt water, and the concentration of the salt water is preferably 3%. The weight of water earthworms fed every day is preferably 35% to 65% of the fish body weight, and 35%, 40%, 45%, 50%, 55%, 60% and 65% of the fish body weight can be selected. The number of daily feedings is preferably 4 times. Before each feeding, it is preferred to remove the remaining bait in the pond to ensure the freshness of the feeding bait at any time.

[0032] In the present invention, the time for feeding pig liver for seedling cultivation is preferably 6 to 9 days, and 6, 7, 8 and 9 days can be selected. When feeding the pig liver, the pig liver is preferably cut into long thin slices for feeding. The weight of the pig liver fed per day is preferably 20% to 30% of the fish body weight, and 20%, 22%, 24%, 26%, 28% and 30% of the fish body weight can be selected. The number of daily feedings is preferably 4 times, and before each feeding, it is preferably necessary to remove the remaining bait in the pond.

[0033] In the present invention, the conversion feed 1 can be composed of 35% catfish seed powder and 65% pig liver, or 40% catfish seed powder and 60% pig liver, or 45% catfish seed powder and 55% pig liver; the conversion feed 2 can be composed of 55% catfish seed powder and 45% pig liver, or 60% catfish seed powder and 40% pig liver, or 70% catfish seed powder and 30% pig liver; the conversion feed 3 can be composed of 55% catfish seed powder and 45% pig liver, or 60% catfish seed powder and 40% pig liver, or 70% catfish seed powder and 30% pig liver; the conversion feed 4 can be composed of 55% catfish seed powder and 45% pig liver, or 60% catfish seed powder and 40% pig liver, or 70% catfish seed powder and 30% pig liver. Catfish seed powder, 15% pork liver and 30% water, or 60% catfish seed powder, 20% pork liver and 20% water, or 70% catfish seed powder, 20% pork liver and 10% water; the conversion feed 4 can be composed of 75% catfish seed powder, 5% pork liver and 20% water, or 80% catfish seed powder, 10% pork liver and 10% water, or 85% catfish seed powder, 10% pork liver and 5% water. In the present invention, the shape of the conversion feed is preferably strips, the length of the strips is preferably 3cm to 5cm, and it is preferably made by a meat grinder.

[0034] In the present invention, the time for feeding the conversion feed 1 is preferably 2 to 3 days, the time for feeding the conversion feed 2 is preferably 3 to 4 days, the time for feeding the conversion feed 3 is preferably 3 to 5 days, and the time for feeding the conversion feed 4 is preferably 5 to 6 days. The weight of the conversion feed 1, the conversion feed 2, the conversion feed 3 or the conversion feed 4 fed per day is preferably 10% to 15% of the fish body weight, and can be selected as 10%, 11%, 12%, 13%, 14% or 15% of the fish body weight.

[0035] In the method of the present invention, it is preferred to further include the step of screening fish once every 6 to 9 days, and after screening, the fish are divided into ponds according to specifications for feeding, which can effectively prevent cannibalism caused by large differences in specifications; more preferably, the seedlings on the screen are fed in the next step, and the seedlings under the screen are fed repeatedly in the previous step until the fry can stay on the screen. The time interval for screening fish can be selected as 6 days, 7 days, 8 days or 9 days. The present invention separates the seedlings into different specifications for feeding, which can effectively prevent cannibalism caused by large differences in specifications. In the present invention, after feeding water earthworms to open the seedlings for 6 to 9 days, the fish are screened, the seedlings on the screen are transferred to another pond to start feeding pig liver for seedling cultivation, the seedlings under the screen repeat the step of feeding water earthworms to open the seedlings until the fry can stay on the screen, and the time for repeating feeding water earthworms to open the seedlings is preferably 3 to 5 days, and then the step of feeding pig liver for seedling cultivation is performed. In the present invention, after feeding pig liver for 6 to 9 days for seedling cultivation, the fish are screened, the seedlings on the screen are transferred to another pond to start feeding the transfer feed step in sequence, and the seedlings under the screen repeat the step of feeding pig liver for seedling cultivation until the fry can stay on the screen, and then the step of feeding the transfer feed in sequence is performed. In the present invention, after feeding the transfer feed for 6 to 9 days, the fish are screened, the seedlings on the screen are transferred to another pond to start feeding the next transfer feed, and the seedlings under the screen repeat the step of feeding the transfer feed until the fry can stay on the screen, and then the feeding of the next transfer feed is performed. Since the fry under the screen of the screened fish need to repeat the transfer feeding step each time, the time for finally completing the transfer is 3 to 7 days later than the time for the fry on the screen to complete the transfer.

[0036] In the present invention, bamboo sieves are preferably used when screening fish. The use of bamboo sieves is to screen fry through its narrow "eye" gaps, and the fry have the nature of resisting water, so that the fry can "escape" through the sieve, thereby achieving size separation, making the catfish fry in the breeding process more neat, reducing mutual killing, and facilitating management and feeding. When the fry body length is less than 3.3cm, it is preferred to use an 8-day sieve, when the fry body length is more than 3.3cm and less than 4.6cm, it is preferred to use a 9-day sieve, when the fry body length is more than 4.6cm and less than 5.9cm, it is preferred to use a 10-day sieve, when the fry body length is more than 5.9cm and less than 7.9cm, it is preferred to use an 11-day sieve; when the fry body length is more than 7.9cm and less than 10cm, a 12-day sieve is used. The present invention does not specifically limit the specific source of the bamboo sieve.

[0037] In the present invention, after the feeding of the transfer feed 4 is completed, the catfish pellet feed is completely fed. The catfish pellet feed is preferably an expanded floating feed, the particle size of the catfish pellet feed is preferably 1.0 mm to 2.0 mm, and the protein content of the catfish pellet feed is preferably above 42%.

[0038] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0039] In the following embodiments, unless otherwise specified, all of them are conventional methods.

[0040] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0041] Example 1

[0042] The method for converting catfish seedlings into food of the present invention was carried out in a workshop of a breeding farm in Deyang, Sichuan. The breeding pool in the workshop was a cement pool with a square shape of 5 m on a side and an area of ​​25 m 2 On March 17 of that year, 34,000 largemouth catfish seedlings were purchased and stocked in two cement ponds, with 17,000 seedlings in each pond. The average size of the seedlings was 0.65g / tail. The water temperature was 22℃ when the seedlings were put into the ponds. After entering the ponds, 0.5g / m 3 Disinfection with iodine preparations;

[0043] Feed the water earthworms that have been disinfected and cleaned by soaking in 3% salt water on the day after entering the pond. The daily feeding amount is 7kg / pond, divided into four meals. Before each feeding, remove the remaining water earthworm bait in the pond to keep the bait fresh.

[0044] On March 24, 7 days after feeding, the catfish fry in the two ponds were screened for fish for the first time, specifically using an 8-day bamboo sieve with a diameter of 60 cm and a depth of 30 cm, and the two breeding ponds were divided into four ponds, of which three were for fry over 8 days old, with a specification of about 1.1 g / tail, and one was for fry under 8 days old, with a specification of about 0.7 g / tail; the fry on the sieve were fed with pig liver for seedling cultivation, and the fry under the sieve were continuously fed with water earthworms for 7 days, and then screened with an 8-day bamboo sieve, and the result showed that all of them were fry on the sieve, and then the pig liver was fed; the pig liver was frozen in a freezer before use, and was taken out before feeding, cut into long thin slices for feeding, and four meals were fed per day, and the weight of the pig liver fed to each pond per day was 30% of the weight of the fry in each pond, and the residual bait in the pond was fished out before each feeding;

[0045] On March 31, the fry on the sieve that were screened for the first time on March 24 were screened for the second time, using a 9-day bamboo sieve for screening. This time, the four pools were divided into six, with fry over 9 days old occupying five pools and fry under 9 days old occupying one pool; at this time, the specification of the fry on the sieve reached 2.3g / tail, and they were fed with transition feed in sequence, as shown in Table 1. The largemouth catfish fry powder in Table 1 was purchased from Sichuan Tongwei Feed Co., Ltd., with a protein content of 42%, and the product name was Tongwei 141 largemouth catfish fry compound feed powder; the specification of the sieved fry was 1.2g / tail, and pig liver was repeatedly fed for fry cultivation until the 9-day bamboo sieve was used for screening, and then the fry in Table 1 were fed.

[0046] Table 1 Feeding of transitional feeds in sequence

[0047]

[0048]

[0049] Note: The converted feeds in Table 1 are made by a meat grinder into 3 cm strips. The daily feeding amount of each converted feed per pond is 15% of the weight of the seedlings in the pond.

[0050] On the 7th day after the second sieved fish were fed with the transition feed shown in Table 1 (i.e. after the feeding of transition feed 2 was completed), the fish were sieved for the third time, sieved using a 10-minute sieve, the sieved fry were fed with transition feed 3 and transition feed 4, and the sieved fry were repeatedly fed with transition feed 2 until all were sieved fry when sieved using a 10-minute sieve, and then transition feed 3 and transition feed 4 were fed.

[0051] By April 14, the fry on the sieve of each sifted fish were completely fed. The fry under the sieve of each sifted fish accounted for a small part of all the fry put in. Because the feeding steps were repeated, the feeding completion time was 7 days later than that of the fry on the sieve. By April 21, the fry under the sieve were completely fed. According to calculation, the average specification of the fry reached 7.8g / tail when all the fry were completely fed with a large-mouthed catfish granular feed with a particle size of 1.0mm (the large-mouthed catfish granular feed was purchased from Sichuan Tongwei Feed Co., Ltd., product name: Tongwei 141 large-mouthed catfish fry feed). According to statistics, the survival rate of large-mouthed catfish fry after feeding was 89.5%.

[0052] Example 2

[0053] The method for converting catfish seedlings into food of the present invention is carried out in a greenhouse of a family farm in Shuangliu, Sichuan. The breeding pond in the greenhouse is a cement pond with a rectangular shape of 6m long and 5m wide. The breeding pond area is 30m 2 On March 29 of that year, 19,000 catfish seedlings were purchased and stocked in a cement pond. The average size of the seedlings was 1.62g / tail. The water temperature in the pond was 21℃. After the seedlings entered the pond, 0.5g / m 3 Disinfection with iodine preparations;

[0054] Feed the water earthworms that have been disinfected and cleaned by soaking in 3% salt water on the day after entering the pond. The daily feeding amount is 12kg / pond, divided into four meals. Remove the remaining water earthworm bait in the pond before each feeding to keep the bait fresh.

[0055] On April 5, 7 days after feeding, the catfish fry were screened for the first time to thin out the density. Specifically, a 10-day bamboo sieve was used to divide the fry into three pools, two of which were for fry on the sieve and one for fry under the sieve. After screening and dividing the pools into pools for fry on the sieve and fry under the sieve, all of them began to be fed with pig liver. The pig liver was frozen in a freezer before use, and was taken out before feeding and cut into 3 cm to 5 cm long thin slices for feeding. Four meals were fed per day, and the weight of the pig liver fed to each pool per day was 20% of the weight of the fry in each pool, and the residual bait in the pool was removed before each feeding.

[0056] On April 12, 7 days later, the fry were screened for the second time using an 11-day bamboo sieve. This time, the three ponds were divided into four, with large-sized fry over 11 days old accounting for three and small-sized fry under 11 days old accounting for one; the large-sized fry over 11 days old were sequentially fed with transition feed, as shown in Table 2. The large-mouthed catfish fry powder in Table 2 was purchased from Sichuan Tongwei Feed Co., Ltd., with a protein content of 42%, and the product name was Tongwei 141 large-mouthed catfish fry compound feed powder; the fry under 11 days old were repeatedly fed with pig liver for fry cultivation until the 11-day bamboo sieve was used for screening, and then the fry were all on the sieve, and then the feeding in Table 2 was carried out.

[0057] Table 2 Feeding of transitional feeds in sequence

[0058]

[0059] Note: The converted feeds in Table 2 are made into small strips by a meat grinder. The daily feeding amount of each type of converted feed per pond is 10% of the weight of the seedlings in the pond.

[0060] On April 19, the fry on the sieve that were screened for the second time were screened for the third time using a 12-day bamboo sieve. This time, the four ponds were divided into six, with large-sized fry over 12 days old occupying five ponds and smaller-sized fry under 12 days old occupying one pond; the fry on the sieve of 12 days old were fed with conversion feed 3 and conversion feed 4, and the fry below the sieve were repeatedly fed with conversion feed 2 until all the fry were on the sieve when the 12-day sieve was used for screening, and then they were fed with conversion feed 3 and conversion feed 4.

[0061] By April 30, the fry on the sieve of each sifted fish were completely fed. The fry under the sieve of each sifted fish accounted for a small part of all the fry put in. Because the feeding steps were repeated, the feeding completion time was 3 days later than that of the fry on the sieve. By May 3, the feeding of the fry under the sieve was completed. According to calculation, the average specification of the fry when all the fry were fed was 12.6g / tail. They began to be fully fed with a large-mouthed catfish granular feed with a particle size of 2.0mm (the large-mouthed catfish granular feed was purchased from Sichuan Tongwei Feed Co., Ltd., product name: Tongwei 141 large-mouthed catfish compound feed). According to statistics, the survival rate of large-mouthed catfish fry after feeding was 95.1%.

[0062] Comparative Example 1

[0063] The difference from Example 2 is that a single water earthworm is used for feeding and the fish are screened once every 12 days, and the rest is the same as Example 2. As of May 3, the average size of the seedlings is only 7.3g / tail. According to statistics, the survival rate of the large mouth catfish seedlings for feeding is less than 60%.

[0064] Comparative Example 2

[0065] The difference from Example 2 is that the feed conversion feed 1 is not contained, and the feed conversion feed 2 is directly fed, and the rest is the same as Example 2. The results show that the average size of the seedlings is 11.7g / tail by May 3, and according to statistics, the survival rate of the seedlings of the catfish is 78%.

[0066] Comparative Example 3

[0067] The difference from Example 2 is that the proportions of the conversion feed 1 to the conversion feed 4 are adjusted to be respectively composed of 30% catfish seed powder and 70% pig liver, the conversion feed 2 is composed of 40% catfish seed powder and 60% pig liver, the conversion feed 3 is composed of 60% catfish seed powder and 40% pig liver; the conversion feed 4 is composed of 90% catfish seed powder, 5% pig liver and 5% water; the rest is the same as Example 2. The results show that the average size of the seed is 11.3g / tail by May 3, and according to statistics, the survival rate of catfish seed conversion is 85%.

[0068] Example 3

[0069] The difference from Example 2 is that the transition feed is fed in sequence as shown in Table 3, and the rest is the same as Example 2.

[0070] Table 3 Feeding of transitional feeds in sequence

[0071]

[0072] Note: The converted feeds in Table 3 are made from meat grinders into 4 cm strips. The daily feeding amount of each converted feed per pond is 15% of the weight of the seedlings in the pond.

[0073] The results showed that by April 26, the fry on the sieves of each sifting were completely fed. For the fry under the sieves of each sifting, which accounted for a small part of all the fry put in, the feeding process was repeated, so the feeding was completed 4 days later than that of the fry on the sieves. By April 30, the feeding of the fry under the sieves was completed. According to calculations, the average size of the fry when all the fry were fed was 13.0g / tail. They began to be fully fed with a 2.0mm particle size catfish granular feed (the catfish granular feed was purchased from Sichuan Tongwei Feed Co., Ltd., product name: Tongwei 141 catfish granular feed). According to statistics, the survival rate of catfish fry after feeding was 93.5%.

[0074] Example 4

[0075] The difference from Example 2 is that the feed for feeding is shown in Table 4, and the rest is the same as Example 2.

[0076] Table 4 Feeding of transitional feed in sequence

[0077]

[0078] Note: The converted feeds in Table 4 are made from 4 cm strips using a meat grinder. The daily feeding amount of each converted feed per pond is 13% of the weight of the seedlings in the pond.

[0079] The results showed that by April 25, the fry on the sieves of each sifting were completely fed. For the fry under the sieves of each sifting, which accounted for a small part of all the fry put in, the feeding process was repeated, so the feeding was completed 5 days later than that of the fry on the sieves. By April 30, the feeding of the fry under the sieves was completed. According to calculations, the average specification of the fry when all the fry were fed was 12.4g / tail. They began to be fully fed with a 2.0mm particle size catfish granular feed (the catfish granular feed was purchased from Sichuan Tongwei Feed Co., Ltd., product name: Tongwei 141 catfish granular feed). According to statistics, the survival rate of catfish fry after feeding was 94.8%.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for converting catfish fry into food, characterized in that: The method comprises the following steps: firstly feeding water earthworms to open the seedlings, then feeding pig liver to cultivate the seedlings, and then feeding the conversion feed 1, the conversion feed 2, the conversion feed 3 and the conversion feed 4 in sequence; The transition feed 1 is composed of 35% to 45% catfish seed powder and 55% to 65% pig liver; The transition feed 2 is composed of 55% to 70% catfish seed powder and 30% to 45% pig liver; The transition feed 3 is composed of 55% to 70% catfish seed powder, 15% to 20% pig liver and 10% to 30% water; The transition feed 4 is composed of 75% to 85% catfish seed powder, 5% to 10% pig liver and 5% to 20% water; The protein content of the catfish fry powder is more than 42%.

2. The method according to claim 1, characterized in that The specification of the largemouth catfish seedlings is 0.5g / tail to 1.7g / tail.

3. The method according to claim 1, characterized in that The time it takes for the seedlings to start opening is 6 to 9 days after feeding with water earthworms; the weight of water earthworms fed every day should be 35% to 65% of the fish body weight.

4. The method according to claim 1, characterized in that: The time for feeding pig liver for seedling cultivation is 6 to 9 days; the weight of pig liver fed every day is 20% to 30% of the fish body weight.

5. The method according to claim 1, characterized in that The time for feeding the converted feed 1 is 2 to 3 days, the time for feeding the converted feed 2 is 3 to 4 days, the time for feeding the converted feed 3 is 3 to 5 days, and the time for feeding the converted feed 4 is 5 to 6 days.

6. The method according to claim 1, characterized in that The weight of the converted feed 1, the converted feed 2, the converted feed 3 or the converted feed 4 fed every day is 10% to 15% of the fish body weight.

7. The method according to claim 1, characterized in that The method also includes a step of screening the fish once every 6 to 9 days.

8. The method according to claim 7, characterized in that The fry on the sieve are fed in the next step, and the fry under the sieve are fed by repeating the previous step until the fry can remain on the sieve; when the fry body length is less than 3.3cm, use the 8-day sieve; when the fry body length is more than 3.3cm and less than 4.6cm, use the 9-day sieve; when the fry body length is more than 4.6cm and less than 5.9cm, use the 10-day sieve; when the fry body length is more than 5.9cm and less than 7.9cm, use the 11-day sieve; when the fry body length is more than 7.9cm and less than 10cm, use the 12-day sieve.

9. The method according to claim 1, characterized in that: After the feeding of the transition feed 4 is completed, the catfish are completely fed with a pelleted feed.

10. The method according to claim 9, characterized in that The particle size of the catfish pellet feed is 1.0 mm to 2.0 mm, and the protein content of the catfish pellet feed is more than 42%.

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