A method for breeding and culturing daphnia magna

Abstract

The application provides a breeding method of daphnia magna, which comprises the following steps: S1, putting collected daphnia magna into an expansion culture pool, and the initial density of the daphnia magna is 30-40 ind. / L; S2, adding lake water or tap water into the expansion culture pool, and then putting farmyard manure, leucine and fermentation products fermented by bean dregs and wheat bran into the expansion culture pool, and expanding the daphnia magna under the condition that the water temperature is 15-25 DEG C, the pH value is 7-8 and the dissolved oxygen is greater than 2 mg / L. The leucine in the fermentation products of the bean dregs and the wheat bran cooperatively accelerates the growth speed of the daphnia magna, improves the reproduction rate of the daphnia magna, and ensures that the size and the quantity of the daphnia magna are rapidly increased in a short time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of daphnia culture, and particularly relates to a breeding method of daphnia magna. BACKGROUND

[0002] Yilong Lake is one of the famous plateau lakes in Yunnan Province, with a wide area and beautiful scenery, and is known as "miniature West Lake in Yunnan". In recent years, with the increase of local tourism resources, the growth of population around the lake and the increasing pressure on lake resources, the water quality of the lake shows a downward trend, especially the rapid shrinkage of the drought and flood, and the rapid shrinkage of the submerged plants. The lake ecosystem rapidly changes from a grass-type plant-based to an algae-based, with high content of water organic matter and high chemical oxygen demand (COD) all year round. The abnormal proliferation of harmful algae, especially filamentous blue-green algae such as pseudochlorella, greatly affects the ecological service function of Yilong Lake.

[0003] Under this background, it is particularly important to find an effective method for treating the water quality of Yilong Lake. Studies have shown that daphnia magna has a significant inhibitory effect on the growth of algae in eutrophic water bodies, plays an important role in the material cycle and energy flow of aquatic ecosystems, and is an important link in the cycle of aquatic ecosystems, and has been widely used by many scientists.

[0004] However, daphnia magna has high requirements for the culture environment, such as water temperature, water quality, light intensity and feed, etc. Unstable culture conditions will lead to poor propagation effect and low breeding efficiency. Secondly, stable and high-quality feed supply is the key to ensure the normal growth and reproduction of daphnia magna. The existing feed types and quality may not fully meet the needs of daphnia magna. Therefore, it is necessary to provide a daphnia magna breeding method with high breeding efficiency. SUMMARY

[0005] Therefore, the present application provides a daphnia magna breeding method with high breeding efficiency.

[0006] The technical scheme of the present application is implemented as follows: the present application provides a daphnia magna breeding method, comprising the following steps:

[0007] S1, putting the collected daphnia magna into the expansion tank, and the initial density of daphnia magna is 30-40 ind. / L;

[0008] S2, adding lake water or tap water to the expansion tank, and then adding farmyard manure, leucine and fermentation products fermented from bean dregs and wheat bran, and expanding daphnia magna under the condition of water temperature 15-25℃, pH value 7-8 and dissolved oxygen greater than 2mg / L.

[0009] Farmyard manure is rich in organic matter and micronutrients, including nitrogen, phosphorus, potassium, and other essential elements, which are important sources of nutrition for Daphnia magna. In addition, farmyard manure can promote the growth of phytoplankton and zooplankton in water bodies, which are also natural food for Daphnia magna. During fermentation, bean dregs and wheat bran can degrade macromolecular organic matter into small molecular organic acids, amino acids, and yeast, which are high-quality food for Daphnia magna. Moreover, microorganisms such as yeast and lactic acid bacteria in the fermentation products can help Daphnia magna better digest and utilize other nutrients, achieving the purpose of improving feed efficiency and improving the efficiency of the digestive system. Leucine can promote protein synthesis by activating the mTOR signaling pathway, thereby accelerating the growth rate of Daphnia magna and improving its reproduction rate, ensuring rapid increase in size and number in a short period of time.

[0010] Farmyard manure provides basic nutrition and promotes the growth of phytoplankton, while fermentation products provide easily digestible organic acids and probiotics. Leucine accelerates growth and reproduction speed, and these feeds complement each other to fully meet the nutritional needs of water fleas, improve their growth rate and reproduction rate, and thus accelerate the expansion pace.

[0011] On the basis of the above technical scheme, preferably, the fermentation method of bean dregs and wheat bran is as follows: bean dregs, wheat bran, and brown sugar are mixed and stirred uniformly, then EM bacteria and Bacillus subtilis are added and stirred to dissolve, and then aerobic fermentation is carried out at 30-40℃ for 14-15d. After fermentation, the fermentation liquid is obtained by filtration.

[0012] EM bacteria and Bacillus subtilis both have the effect of improving fermentation efficiency and increasing nutritional ingredients. In addition, EM bacteria can reduce the pH value of the fermentation environment through the production of organic acids, inhibit the growth of harmful microorganisms, and create an environment conducive to the growth of fermentation bacteria. Bacillus subtilis has strong adaptability and competitiveness, can grow in complex fermentation environment, inhibit the growth of harmful bacteria, and improve the safety of fermentation products.

[0013] On the basis of the above technical scheme, preferably, the weight ratio of bean dregs:wheat bran:brown sugar:water is (5-8):(3-5):(0.3-0.5):(20-25).

[0014] On the basis of the above technical scheme, preferably, the amount of EM bacteria and Bacillus subtilis used is 0.01%-0.03% and 0.3%-0.5% of the mixture of bean dregs and wheat bran, respectively.

[0015] On the basis of the above technical scheme, preferably, the fermentation product and leucine belong to nutritional supplements, which need to be added in batches for multiple times to meet the nutritional requirements of the daphnia magna for continuous growth.

[0016] On the basis of the above technical scheme, preferably, the farmyard manure is base fertilizer, and is fed once every 7 days, with 300-500g / cubic water each time.

[0017] On the basis of the above technical scheme, preferably, in step S1, during the expansion culture, the expansion culture tank is also added with citric acid chelated magnesium and photosynthetic bacterial liquid.

[0018] The citric acid chelated magnesium can be efficiently absorbed by the daphnia magna, so that the daphnia magna can rapidly supplement magnesium ions, enhance the stress resistance and resistance, improve the survival rate of the daphnia magna in a high-density culture environment, and improve the quality and quantity of the daphnia magna.

[0019] The photosynthetic bacteria can consume CO2 in water and release O2 through photosynthesis, and can also degrade ammonia nitrogen generated in the large-scale expansion culture of the daphnia magna, purify the water quality, and maintain the stability of the water environment. Meanwhile, the photosynthetic bacteria can also synthesize various organic matters such as amino acids, vitamins and polysaccharides through photosynthesis, as a supplementary bait for the daphnia magna, to provide rich nutrition and help the rapid growth and reproduction of the daphnia magna.

[0020] On the basis of the above technical scheme, preferably, the citric acid chelated magnesium and the bacterial liquid are fed once every 2-3 days, the citric acid chelated magnesium is fed 4-6g / cubic water each time, the bacterial liquid is fed 20-40g / cubic water each time, and the number of live bacteria in the bacterial liquid is 3-5x10 9 CFU / g.

[0021] On the basis of the above technical scheme, preferably, the water is replaced by 1 / 3-1 / 2 every 3-5 days during the expansion culture, and fresh water source is supplemented.

[0022] The daphnia magna breeding method with high breeding efficiency has the following beneficial effects relative to the prior art:

[0023] The fermentation product of the bean dregs and wheat bran in the present application provides the daphnia magna with organic acids, amino acids, yeast and the like required for growth, and the microorganisms such as yeast and lactic acid bacteria in the fermentation product can also help the daphnia magna to better digest and utilize other nutrients, so as to achieve the purposes of improving the feed efficiency and improving the efficiency of the digestive system of the daphnia magna. The leucine promotes protein synthesis by activating the mTOR signal pathway, accelerates the growth rate of the daphnia magna, improves the reproduction rate of the daphnia magna, and ensures that the size and quantity of the daphnia magna are rapidly increased in a short time. The fermentation product of the bean dregs and wheat bran and the leucine synergistically act, so as to obtain high-density daphnia magna in a short time.

[0024] The citric acid chelated magnesium in the present application rapidly replenishes magnesium ions for the daphnia magna, enhances the stress resistance and resistance of the daphnia magna, improves the survival rate of the daphnia magna in a high-density culture environment, and improves the quality and quantity of the daphnia magna. The photosynthetic bacteria help the daphnia magna to grow and reproduce rapidly by improving the water quality and nutrient supply. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 The daphnia magna collected from Yilong Lake. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] The large daphnia required by the present application is from the lake area and wetland of Yilong Lake (Yunnan Province, Honghe Hani and Yi Autonomous Prefecture, China), and the healthy wild large daphnia with a length of 2-4 mm and activity in the original water body of Yilong Lake is captured by using a No. 25 plankton net. The bottom water outlet piston switch of the plankton net is closed, and the net is slowly dragged back and forth at a speed of 20-30 cm / s at the surface layer to 0.5 m deep of the water, about 1-3 min, after the net is obviously filled with plankton and aquatic plants, the plankton net is taken out of the water surface, the water in the net is naturally filtered out through the mesh, and when there is little water sample (5-10 mL) left at the bottom, the bottom outlet is moved into a qualitative sampling bottle, and the bottom piston switch is opened to collect the qualitative sample.

[0029] After the sample is collected, the qualitative sample is observed under a microscope in the laboratory (orthosteric biological microscope or inverted biological microscope: objective lens 4x, 10x, 20x, 40x; eyepiece 10x or 15x), and after the large daphnia is identified and confirmed, several healthy female parents are selected and cultured in a 50 mL beaker. The large daphnia with the largest reproduction amount is selected, cloned, and made into a pure strain of Yilong Lake.

[0030] A 3m long, 6m wide, 1m deep extension culture pool is dug as a domestication device, clean lake water or tap water is injected, the water depth is 0.5m, 8g / cubic meter of sodium thiosulfate is added to the water body for disinfection, and then the large daphnia is put in for culture under natural light conditions to avoid direct sunlight. The extension culture pool is provided with a thermometer, a pH meter, and a dissolved oxygen detector to monitor the temperature, pH, and dissolved oxygen of the water body in real time for convenient adjustment and control. The specific subsequent culture method is shown in the examples.

[0031] Example 1

[0032] The propagation and cultivation method of the large daphnia in this example includes the following steps:

[0033] S1, the collected large daphnia is put into the extension culture pool (3m x 6m x 1m), and the initial density of the large daphnia is 30 ind. / L, then mature farmyard manure, leucine, and fermentation products fermented from bean dregs and wheat bran are put into the water body of the extension culture pool, and the extension culture is carried out under the conditions of water temperature 15℃, pH value 7, and dissolved oxygen 2mg / L. As the density of the large daphnia increases, the dissolved oxygen content is adaptively increased. The water is replaced by 1 / 3 every 3 days during the extension culture, and fresh water source is supplemented.

[0034] Among them, the farmyard manure is a base fertilizer, which is fed once every 7 days, and 300g / cubic water is fed each time; the fermentation product is fed once every 1 day, and 10g / cubic water is fed each time; and the leucine is fed once every 2 days, and 2g / cubic water is fed each time.

[0035] The fermentation method of the bean dregs and wheat bran is as follows: 50 kg of bean dregs, 30 kg of wheat bran, 3 kg of brown sugar and 200 water are put into a fermentation tank, stirred uniformly, then 80 g of EM bacteria and 240 g of Bacillus subtilis are added and stirred to dissolve in water, then aerobic fermentation is carried out at 30℃ for 14 days; during the fermentation process, the fermentation tank is opened, oxygen is supplied for 5 hours every day, and when there is an acid aroma, it can be judged that the fermentation is basically completed; after the fermentation is completed, the fermentation liquid is obtained by filtering with a 150-mesh mesh bag.

[0036] Example 2

[0037] The method for breeding and culturing Daphnia magna in this embodiment includes the following steps:

[0038] S1, the collected Daphnia magna is put into the expansion tank (3m x 6m x 1m), and the initial density of Daphnia magna is 30ind. / L, then the mature farmyard manure, leucine, citric acid chelated magnesium, photosynthetic bacteria liquid and fermentation product fermented from bean dregs and wheat bran are put into the water body of the expansion tank, and the expansion breeding is carried out under the conditions of water temperature 15℃, pH value 7 and dissolved oxygen 2mg / L; with the increase of the density of Daphnia magna, the adaptability is improved and the dissolved oxygen content is increased.

[0039] The farmyard manure is the basic nutrition, and the leucine, citric acid chelated magnesium, photosynthetic bacteria liquid and fermentation product fermented from bean dregs and wheat bran are the synergists. The farmyard manure is fed once every 7 days, and each time 300g / cubic water is fed; the fermentation product is fed once every 1 day, and each time 10g / cubic water is fed; the leucine, citric acid chelated magnesium and photosynthetic bacteria liquid are fed once every 2 days, and the leucine is fed 2g / cubic water each time, the citric acid chelated magnesium is fed 4g / cubic water each time, and the bacteria liquid is fed 20g / cubic water each time, and the number of living bacteria in the bacteria liquid is 3-5x10 9 CFU / g. During the expansion, 1 / 3 of the water is replaced every 3 days, and fresh water source is supplemented.

[0040] The fermentation method of the bean dregs and wheat bran is as follows: 50 kg of bean dregs, 30 kg of wheat bran, 3 kg of brown sugar and 200 water are put into a fermentation tank, stirred uniformly, then 80 g of EM bacteria and 240 g of Bacillus subtilis are added and stirred to dissolve in water, then aerobic fermentation is carried out at 30℃ for 14 days; during the fermentation process, the fermentation tank is opened, oxygen is supplied for 5 hours every day, and when there is an acid aroma, it can be judged that the fermentation is basically completed; after the fermentation is completed, the fermentation liquid is obtained by filtering with a 150-mesh mesh bag.

[0041] Example 3

[0042] The method for breeding and culturing Daphnia magna in this embodiment includes the following steps:

[0043] S1, put the collected daphnia magna into the expansion pond (3m x 6m x 1m), the initial density of daphnia magna is 35 ind. / L, then put the rotten farmyard manure, leucine, citric acid chelated magnesium, photosynthetic bacteria liquid and fermentation product fermented by bean dregs and wheat bran into the water body of the expansion pond, under the conditions of water temperature 25℃, pH value 7.5 and dissolved oxygen 5mg / L, expand and breed, with the increase of the density of daphnia magna, the adaptability is improved, the dissolved oxygen content is improved, and the water is replaced by 1 / 2 every 5 days during the expansion.

[0044] The farmyard manure is fed once every 7 days, 350g / cubic water each time; the fermentation product is fed once every 2 days, 13g / cubic water each time; the leucine, citric acid chelated magnesium and photosynthetic bacteria liquid are fed once every 3 days, the leucine is fed 3g / cubic water each time, the citric acid chelated magnesium is fed 6g / cubic water each time, and the photosynthetic bacteria liquid is fed 30g / cubic water each time, the number of living bacteria in the liquid is 3-5x10 9 CFU / g.

[0045] The fermentation method of bean dregs and wheat bran is as follows: 60kg of bean dregs, 50kg of wheat bran, 3.5kg of brown sugar and 225kg of water are put into a fermentation tank, stirred uniformly, 22g of EM bacteria and 550g of bacillus subtilis are added and stirred to dissolve in water, then aerobic fermentation is carried out at 30℃ for 15 days, during the fermentation process, the fermentation tank is opened, oxygen is supplied for 5 hours every day, and when there is sour smell, it can be judged that the fermentation is basically completed, after the fermentation is completed, the fermentation liquid is obtained by filtering with a 150 mesh bag.

[0046] Example 4

[0047] The expansion breeding method of daphnia magna in this example includes the following steps:

[0048] S1, put the collected daphnia magna into the expansion pond (3m x 6m x 1m), the initial density of daphnia magna is 35 ind. / L, then put the rotten farmyard manure, leucine, citric acid chelated magnesium, photosynthetic bacteria liquid and fermentation product fermented by bean dregs and wheat bran into the water body of the expansion pond, under the conditions of water temperature 25℃, pH value 7.5 and dissolved oxygen 5mg / L, expand and breed, with the increase of the density of daphnia magna, the adaptability is improved, the dissolved oxygen content is improved, and the water is replaced by 1 / 2 every 5 days during the expansion.

[0049] The farmyard manure is fed once every 7 days, 350g / cubic water each time; the fermentation product is fed once every 2 days, 13g / cubic water each time; the leucine, citric acid chelated magnesium and photosynthetic bacteria liquid are fed once every 3 days, the leucine is fed 3g / cubic water each time, the citric acid chelated magnesium is fed 6g / cubic water each time, and the photosynthetic bacteria liquid is fed 30g / cubic water each time, the number of living bacteria in the liquid is 3-5x10 9 CFU / g.

[0050] The fermentation method of the bean dregs and wheat bran is as follows: 80 kg of bean dregs, 40 kg of wheat bran, 3 kg of brown sugar and 210 kg of water are put into a fermentation tank, stirred uniformly, then 24 g of EM bacteria and 480 g of Bacillus subtilis are added and stirred to dissolve in the water, and then aerobic fermentation is carried out at 40℃ for 15 days. During the fermentation process, the fermentation tank is opened, and oxygen is supplied for 5 hours every day. During the fermentation process, the fermentation tank is opened, and oxygen is supplied for 5 hours every day. When there is an acid aroma, it can be judged that the fermentation is basically completed. After the fermentation is completed, the fermentation liquid is obtained by filtering with a 150-mesh mesh bag.

[0051] Example 5

[0052] The method for breeding and culturing Daphnia magna in this embodiment includes the following steps:

[0053] S1, the collected Daphnia magna is put into the expansion tank (3m x 6m x 1m), and the initial density of Daphnia magna is 38ind. / L, then the mature farmyard manure, leucine, citric acid chelated magnesium, photosynthetic bacteria liquid and fermentation product fermented from bean dregs and wheat bran are put into the water body of the expansion tank, and the expansion breeding is carried out under the conditions of water temperature 22℃, pH value 7.5 and dissolved oxygen 4mg / L. With the increase of the density of Daphnia magna, the adaptability is improved, and the dissolved oxygen content is increased. When expanding, the water is changed by 1 / 2 every 5 days, and fresh water source is supplemented.

[0054] The farmyard manure is fed once every 7 days, and each time 400g / cubic water is fed; the fermentation product is fed once every 1 day, and each time 15g / cubic water is fed; the leucine and citric acid chelated magnesium are fed once every 2.5 days, the leucine is fed 4g / cubic water each time, and the citric acid chelated magnesium is fed 5g / cubic water each time; the photosynthetic bacteria liquid is fed once every 3 days, and each time 40g / cubic water is fed, and the number of living bacteria in the bacteria liquid is 3-5x10 9 CFU / g.

[0055] The fermentation method of the bean dregs and wheat bran is as follows: 80 kg of bean dregs, 40 kg of wheat bran, 3 kg of brown sugar and 210 kg of water are put into a fermentation tank, stirred uniformly, then 24 g of EM bacteria and 480 g of Bacillus subtilis are added and stirred to dissolve in the water, and then aerobic fermentation is carried out at 40℃ for 15 days. During the fermentation process, the fermentation tank is opened, and oxygen is supplied for 5 hours every day. During the fermentation process, the fermentation tank is opened, and oxygen is supplied for 5 hours every day. When there is an acid aroma, it can be judged that the fermentation is basically completed. After the fermentation is completed, the fermentation liquid is obtained by filtering with a 150-mesh mesh bag.

[0056] Example 6

[0057] The method for breeding and culturing Daphnia magna in this embodiment includes the following steps:

[0058] S1, the collected daphnia magna is put into the expansion tank (3m x 6m x 1m), the initial density of daphnia magna is 40ind. / L, then the mature farmyard manure, leucine, citric acid chelated magnesium, photosynthetic bacteria liquid, fermentation product fermented by bean dregs and wheat bran are put into the water body of the expansion tank, under the condition of water temperature 20℃, pH value 8, dissolved oxygen 5mg / L, the daphnia magna is expanded and bred, with the increase of the density of daphnia magna, the adaptability of the daphnia magna is improved, the dissolved oxygen content is increased, and the water is replaced by 1 / 3 every 3 days during the expansion.

[0059] The farmyard manure is fed once every 7 days, 450g / cubic water is fed each time; the fermentation product is fed once every 2 days, 18g / cubic water is fed each time; the leucine and citric acid chelated magnesium are fed once every 3 days, 5g / cubic water of leucine is fed each time, 6g / cubic water of citric acid chelated magnesium is fed each time; the photosynthetic bacteria liquid is fed once every 2 days, 35g / cubic water of the photosynthetic bacteria liquid is fed each time, the number of living bacteria in the photosynthetic bacteria liquid is 3-5x10 9 CFU / g.

[0060] The fermentation method of the bean dregs and wheat bran is as follows: 60kg of bean dregs, 40kg of wheat bran, 4kg of brown sugar and 230 water are put into a fermentation tank, after being stirred uniformly, 18g of EM bacteria and 360g of bacillus subtilis are added and stirred to dissolve in the water, then aerobic fermentation is carried out at 35℃ for 14d, during the fermentation process, the fermentation tank is opened, oxygen is supplied for 5h every day, when there is sour smell, it can be judged that the fermentation is basically completed, after the fermentation is completed, the fermentation liquid is obtained by filtering through a 150 mesh bag.

[0061] Comparative example 1

[0062] Comparative example 1 and example 1 are compared, the difference is that the fermentation product fermented by bean dregs and wheat bran is not added, and the other components are the same.

[0063] Comparative example 2

[0064] Comparative example 2 and example 1 are compared, the difference is that EM bacteria and bacillus subtilis are not added when the bean dregs and wheat bran are co-fermented, and the other components are the same.

[0065] Comparative example 3

[0066] Comparative example 3 and example 2 are compared, the difference is that citric acid chelated magnesium and leucine are not added, and the other components are the same.

[0067] Comparative example 4

[0068] Comparative example 4 and example 2 are compared, the difference is that leucine is not added, and the other components are the same.

[0069] Comparative example 5

[0070] Comparative example 5 and example 2 are compared, the difference is that photosynthetic bacteria are not added, and the other components are the same.

[0071] Table 1 Daphnia magna growth rate

[0072]

[0073] As shown in Table 1, the propagation method of the embodiment of the present application obtains 638 ind. / L of Daphnia magna in 7 days, and the proportion of Daphnia magna with a body length greater than 4 mm reaches more than 82%, and the survival rate is as high as more than 91%. The fermentation product of the co-fermentation of bean dregs and wheat bran, citric acid chelated magnesium and leucine increase the egg laying rate of Daphnia magna, speed up the reproduction time, and at the same time increase the immunity and resistance of Daphnia magna, thereby realizing the technical effect of obtaining high-density Daphnia magna in a short time.

[0074] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for propagating and cultivating large Daphnia, characterized in that: Includes the following steps: S1, the collected Daphnia magna was put into the expansion tank, and the initial density of Daphnia magna was 30~40 ind. / L; S2, add lake water or tap water to the expansion tank, then add farmyard manure, leucine, and fermentation products made from soybean residue and wheat bran, and expand the large Daphnia in an environment with a water temperature of 15~25℃, pH value of 7~8, and dissolved oxygen >2mg / L. The fermentation method of soybean residue and wheat bran is as follows: after mixing soybean residue, wheat bran, brown sugar and water, add EM bacteria and Bacillus subtilis, stir to dissolve, and ferment aerobicly at 30~40℃ for 14~15 days. After the fermentation is completed, filter to obtain fermentation liquid. During the expansion culture, citric acid chelated magnesium and photosynthetic bacteria culture also need to be added.

2. The method for propagating and cultivating large-sized Daphnia as described in claim 1, characterized in that: The weight ratio of soybean residue, wheat bran, brown sugar, and water is (5~8):(3~5):(0.3~0.5):(20~25).

3. The method for propagating and cultivating large-sized Daphnia as described in claim 1, characterized in that: The amounts of EM bacteria and Bacillus subtilis used are 0.01%~0.03% and 0.3%~0.5% of the mixture of soybean residue and wheat bran, respectively.

4. The method for propagating and cultivating large Daphnia as described in claim 1, characterized in that: The fermentation product is fed once every 1 to 2 days, with each feeding being 20 to 40 g per cubic meter of water.

5. The method for propagating and cultivating large Daphnia as described in claim 4, characterized in that: The farmyard manure is fed once every 7 days, with each feeding consisting of 300-500g of water.

6. The method for propagating and cultivating large Daphnia as described in claim 4, characterized in that: The leucine is fed once every 2-3 days, with each feeding being 2-5g / cubic meter of water.

7. The method for propagating and cultivating large Daphnia as described in claim 1, characterized in that: The citric acid chelated magnesium and bacterial solution were fed once every 2-3 days. The citric acid chelated magnesium was fed at a rate of 4-6 g / cubic meter of water each time, and the bacterial solution was fed at a rate of 20-40 g / cubic meter of water each time. The number of live bacteria in the bacterial solution was 3-5 × 10⁻⁶. 9 CFU / g.

8. The method for propagating and cultivating large Daphnia as described in claim 1, characterized in that: During propagation, change 1 / 3 to 1 / 2 of the water every 3 to 5 days and add fresh water.

Images