Composite additive for improving survival rate of silkworms and preparation method thereof

Abstract

The invention belongs to the technical field of artificial feed rearing of silkworms, and particularly relates to a composite additive for improving the survival rate of silkworms and a preparation method thereof. The composite additive for increasing the survival rate of silkworms comprises the following raw materials in parts by weight: 20-30 parts of aged zeolite powder, 1-5 parts of chitosan, 5-10 parts of a climbing fig extract, 7-12 parts of quinoa polypeptide and 1-5 parts of trace elements. According to the compound additive disclosed by the invention, germinated climbing fig seeds are selected to prepare the climbing fig extract, and the climbing fig extract and the quinoa polypeptide are added into the silkworm feed, so that the compound additive has an immune regulation effect, and can enhance the immunity of silkworms and reduce the occurrence of diseases, thereby improving the survival rate of the silkworms and reducing the loss for silkworm farmers.

Description

Technical Field

[0001] The invention belongs to the technical field of artificial silkworm feed breeding, and in particular relates to a composite additive for improving the survival rate of silkworms and a preparation method thereof. Background Art

[0002] Sericulture, as the foundation of the silk industry, has a history of thousands of years. Traditional silkworm farming methods mainly rely on the supply of high-quality mulberry leaves and suitable environmental conditions. However, with the acceleration of industrialization and environmental changes, traditional silkworm farming methods face many challenges. Simply relying on the quality and quantity of mulberry leaves to increase the yield and quality of silkworm cocoons is no longer able to meet the current market demand. Therefore, it is particularly important to develop a composite additive that can improve the survival rate of silkworms, enhance the health of silkworms, and increase the yield and quality of silkworm cocoons.

[0003] Among many feed additives, zeolite, as a natural mineral, has attracted widespread attention due to its unique adsorption properties and ion exchange capacity. Zeolite can absorb harmful substances in the intestine, improve the intestinal microenvironment, and promote the healthy growth of silkworms. However, the original zeolite powder has limited effect when used directly in feed, and needs to be aged to improve its adsorption properties and bioavailability. Aged zeolite powder can not only better absorb harmful substances in the intestine, but also provide necessary trace elements, which are conducive to the growth and development of silkworms.

[0004] In order to improve the survival rate of silkworms, many silkworm farmers and researchers have begun to try to use silkworm feed additives. Current silkworm feed additives are mainly composed of antibiotics, vitamins, trace elements, amino acids, etc. These additives can enhance the disease resistance and growth rate of silkworms to a certain extent, but there are some problems. For example, the dosage of antibiotics and fungicides in some additives is too large, which leads to the decline of cocoon quality, poor resistance of silkworms, and easy infection by bacteria or viruses, resulting in a low survival rate.

[0005] In view of the problems existing in the existing silkworm feed additives, it is of great significance to develop a composite additive that can improve the survival rate of silkworms, enhance the health of silkworms, and increase the yield and quality of silk cocoons. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the primary purpose of the present invention is to provide a composite additive for improving the survival rate of silkworms.

[0007] Another object of the present invention is to provide a method for preparing a composite additive for improving the survival rate of silkworms.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A composite additive for improving the survival rate of silkworms comprises the following raw materials in parts by weight: 20-30 parts of aged zeolite powder, 1-5 parts of chitosan, 5-10 parts of Ficus pumila extract, 7-12 parts of quinoa polypeptide and 1-5 parts of trace elements.

[0010] Furthermore, the preparation process of the Ficus pumila extract is as follows: sowing Ficus pumila seeds in the soil, controlling the temperature at 25-30°C and the relative humidity of the soil at 80-90%, collecting the germinated Ficus pumila seeds after 5-10 days, cleaning them, crushing them, adding them to an ethanol aqueous solution, heating and extracting them for a period of time, collecting the extract, concentrating the extract, and freeze-drying it for later use.

[0011] Furthermore, the preparation process of the quinoa polypeptide is as follows:

[0012] (1) washing quinoa seeds and drying them, adding petroleum ether and standing them for a period of time, removing the petroleum ether and then crushing them to obtain quinoa powder, adding α-amylase to hydrolyze them, and obtaining quinoa protein;

[0013] (2) adding trypsin to the quinoa protein of step (1) for enzymatic hydrolysis;

[0014] (3) After the enzymatic hydrolysis is completed, the supernatant is freeze-dried to obtain an enzymatic hydrolysis product, and the collected enzymatic hydrolysis product is separated using an ultrafiltration membrane to collect products with a molecular weight of less than 1 kDa for later use.

[0015] Furthermore, the concentration of the α-amylase is 200-400 U / g.

[0016] Furthermore, in step (1), the hydrolysis temperature is 55-65° C. and the time is 2-4 h.

[0017] Furthermore, the concentration of the trypsin is 400-600 U / g.

[0018] Furthermore, in step (2), the enzymatic hydrolysis temperature is 33-37° C. and the time is 3-4 h.

[0019] The preparation method of the composite additive for improving the survival rate of silkworms is as follows: aged zeolite powder, chitosan, Ficus pumila extract, quinoa polypeptide and trace elements are weighed according to the above weight parts, and fully mixed to obtain the composite additive.

[0020] Furthermore, the trace elements are prepared by mixing copper glycinate, iron glycinate, zinc lactate, and manganese methionine in a mass ratio of 1:5:4:3.

[0021] Furthermore, the preparation of the aged zeolite powder comprises the following steps: calcining the zeolite at 1100-1200° C. for 2-4 hours, and then aging the zeolite at 30-35° C. for 8-10 days.

[0022] The present invention has the following effects compared with the prior art:

[0023] 1. The present invention provides a composite additive for improving the survival rate of silkworms. Aged zeolite powder can load Ficus pumila extract, quinoa polypeptide and trace elements, etc., improve gastrointestinal health, and prolong the action time of each component. In the composite additive of the present invention, Ficus pumila extract is prepared by selecting germinated Ficus pumila seeds, and the Ficus pumila extract and quinoa polypeptide are added to silkworm feed, which has an immunomodulatory effect, can enhance the immunity of silkworms, reduce the occurrence of diseases, thereby improving the survival rate of silkworms and reducing losses for silkworm farmers.

[0024] 2. The present invention provides a method for preparing a composite additive for improving the survival rate of silkworms, and the preparation method is simple and convenient to operate. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below in conjunction with the examples, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. The test methods for which specific experimental conditions are not specified in the following examples are usually carried out according to conventional experimental conditions or according to the experimental conditions recommended by the manufacturer. Unless otherwise specified, the reagents and raw materials used in the present invention can be obtained commercially.

[0026] The trace elements in the embodiments and comparative examples of the present invention are prepared by mixing copper glycinate, iron glycinate, zinc lactate and manganese methionine in a mass ratio of 1:5:4:3.

[0027] Example 1

[0028] A composite additive for improving the survival rate of silkworms comprises the following raw materials in parts by weight: 25 parts of aged zeolite powder, 3 parts of chitosan, 7 parts of Ficus pumila extract, 10 parts of quinoa polypeptide and 3 parts of trace elements.

[0029] The preparation process of the Ficus pumila extract is as follows: sowing Ficus pumila seeds in the soil, controlling the temperature at 25°C and the relative humidity of the soil at 80%, collecting the germinated Ficus pumila seeds after 8 days, cleaning them, crushing them, adding a 7-fold amount of ethanol aqueous solution, heating them to 50°C for ultrasonic extraction for 1.5 hours, filtering, and collecting the filtrate; adding an equal amount of ethanol aqueous solution to the filter residue, ultrasonically extracting at 50°C for 1.5 hours, collecting the extracts after the two extractions, concentrating the extracts, and freeze-drying them for later use;

[0030] The preparation process of the quinoa polypeptide is as follows:

[0031] (1) Take quinoa seeds, wash them with deionized water and dry them, add petroleum ether and heat them to 90° C., wherein the ratio of quinoa seeds to petroleum ether is 10 g:50 mL, stand for 3 hours, remove the petroleum ether and crush them to obtain 100-mesh quinoa powder, add 8 times the amount of water to the quinoa powder, then add 300 U / g α-amylase to hydrolyze, enzymatically hydrolyze at 60° C. for 3 hours, concentrate and purify with a 20 kDa ultrafiltration membrane, and freeze-dry to obtain quinoa protein;

[0032] (2) adding 7 times the amount of water to the quinoa protein in step (1), adjusting the pH to 8.5, and then adding 500 U / g trypsin, and performing enzymatic hydrolysis at 37° C. for 3.5 h;

[0033] (3) After the enzymatic hydrolysis is completed, the enzyme is inactivated by heating in a water bath at 90°C for 10 min. After cooling to room temperature, the mixture is centrifuged at 5000 rpm for 15 min. The supernatant is freeze-dried to obtain an enzymatic hydrolysis product. The collected enzymatic hydrolysis products are separated using an ultrafiltration membrane (molecular weight of 1 kDa), and products with a molecular weight of less than 1 kDa are collected for later use.

[0034] The preparation steps of the aged zeolite powder are as follows:

[0035] The zeolite was heated at 1200°C for 2 hours, cooled to room temperature, aged at 35°C for 9 days, and ground to obtain aged zeolite powder.

[0036] This embodiment also provides a method for preparing a composite additive for improving the survival rate of silkworms. The composite additive is prepared by weighing aged zeolite powder, chitosan, Ficus pumila extract, quinoa polypeptide and trace elements according to the above weight portions and mixing them thoroughly.

[0037] Example 2

[0038] A composite additive for improving the survival rate of silkworms comprises the following raw materials in parts by weight: 20 parts of aged zeolite powder, 1 part of chitosan, 5 parts of Ficus pumila extract, 7 parts of quinoa polypeptide and 1 part of trace elements.

[0039] The preparation process of the Ficus pumila extract is as follows: sowing Ficus pumila seeds in the soil, controlling the temperature at 28°C and the relative humidity of the soil at 85%, collecting the germinated Ficus pumila seeds after 5 days, cleaning them, crushing them, adding an 8-fold amount of ethanol aqueous solution, heating them to 55°C for ultrasonic extraction for 2 hours, filtering, and collecting the filtrate; adding an equal amount of ethanol aqueous solution to the filter residue, ultrasonically extracting at 55°C for 2 hours, collecting the extracts after the two extractions, concentrating the extracts, and freeze-drying them for later use;

[0040] The preparation process of the quinoa polypeptide is as follows:

[0041] (1) Take quinoa seeds, wash them with deionized water and dry them, add petroleum ether and heat them to 90° C., wherein the ratio of quinoa seeds to petroleum ether is 10 g:50 mL, stand for 3 hours, remove the petroleum ether and then crush to obtain 90 mesh quinoa powder, add 5 times the amount of water to the quinoa powder, then add 200 U / g α-amylase for hydrolysis, enzymatic hydrolysis at 55° C. for 4 hours, concentrate and purify with a 20 kDa ultrafiltration membrane, and freeze-dry to obtain quinoa protein;

[0042] (2) adding 6 times the amount of water to the quinoa protein in step (1), adjusting the pH to 8.5, and then adding 400 U / g trypsin, and performing enzymatic hydrolysis at 37° C. for 3 h;

[0043] (3) After the enzymatic hydrolysis is completed, the enzyme is inactivated by heating in a water bath at 90°C for 10 min. After cooling to room temperature, the mixture is centrifuged at 5000 rpm for 15 min. The supernatant is freeze-dried to obtain an enzymatic hydrolysis product. The collected enzymatic hydrolysis products are separated using an ultrafiltration membrane (molecular weight of 1 kDa), and products with a molecular weight of less than 1 kDa are collected for later use.

[0044] The preparation steps of the aged zeolite powder are as follows:

[0045] The zeolite was heated at 1100°C for 4 hours, cooled to room temperature, aged at 33°C for 8 days, and ground to obtain aged zeolite powder.

[0046] This embodiment also provides a method for preparing a composite additive for improving the survival rate of silkworms, and the specific preparation steps are the same as those in Example 1.

[0047] Example 3

[0048] A composite additive for improving the survival rate of silkworms comprises the following raw materials in parts by weight: 30 parts of aged zeolite powder, 5 parts of chitosan, 10 parts of Ficus pumila extract, 12 parts of quinoa polypeptide and 5 parts of trace elements.

[0049] The preparation process of the Ficus pumila extract is as follows: sowing Ficus pumila seeds in the soil, controlling the temperature at 30°C and the relative humidity of the soil at 90%, collecting the germinated Ficus pumila seeds after 10 days, cleaning them, crushing them, adding 9 times the amount of ethanol aqueous solution, heating them to 60°C for ultrasonic extraction for 3 hours, filtering, and collecting the filtrate; adding an equal amount of ethanol aqueous solution to the filter residue, ultrasonically extracting at 60°C for 3 hours, collecting the extracts after the two extractions, concentrating the extracts, and freeze-drying them for later use;

[0050] The preparation process of the quinoa polypeptide is as follows:

[0051] (1) Take quinoa seeds, wash them with deionized water and dry them, add petroleum ether and heat them to 90° C., wherein the ratio of quinoa seeds to petroleum ether is 10 g:50 mL, stand for 3 hours, remove the petroleum ether and crush to obtain 80-mesh quinoa powder, add 10 times the amount of water to the quinoa powder, then add 300 U / g α-amylase for hydrolysis, enzymatic hydrolysis at 65° C. for 2 hours, concentrate and purify with a 20 kDa ultrafiltration membrane, and freeze-dry to obtain quinoa protein;

[0052] (2) adding 8 times the amount of water to the quinoa protein in step (1), adjusting the pH to 8.5, and then adding 600 U / g trypsin and performing enzymatic hydrolysis at 37° C. for 4 h;

[0053] (3) After the enzymatic hydrolysis is completed, the enzyme is inactivated by heating in a water bath at 90°C for 10 min. After cooling to room temperature, the mixture is centrifuged at 5000 rpm for 15 min. The supernatant is freeze-dried to obtain an enzymatic hydrolysis product. The collected enzymatic hydrolysis products are separated using an ultrafiltration membrane (molecular weight of 1 kDa), and products with a molecular weight of less than 1 kDa are collected for later use.

[0054] The preparation steps of the aged zeolite powder are as follows:

[0055] The zeolite was heated at 1150°C for 3 h, cooled to room temperature, and then aged at 30°C for 10 d. The aged zeolite powder was obtained after grinding.

[0056] This embodiment also provides a method for preparing a composite additive for improving the survival rate of silkworms, and the specific preparation steps are the same as those in Example 1.

[0057] Comparative Example 1

[0058] The difference between this comparative example 1 and embodiment 1 is that: the root of Ficus pumila is cleaned, crushed, and then an aqueous solution of 7 times the amount of ethanol is added, heated to 50°C for ultrasonic extraction for 1.5 hours, filtered, and the filtrate is collected; an equal amount of an aqueous solution of ethanol is added to the filter residue, ultrasonic extraction is performed at 50°C for 1.5 hours, the extracts after two extractions are collected, the extracts are concentrated and freeze-dried for later use; and the rest are consistent with embodiment 1.

[0059] Comparative Example 2

[0060] The difference between this comparative example 2 and example 1 is that: the Ficus pumila fruit is cleaned, crushed, and then a 7-fold amount of ethanol aqueous solution is added, heated to 50° C. and ultrasonically extracted for 1.5 hours, filtered, and the filtrate is collected; an equal amount of ethanol aqueous solution is added to the filter residue, ultrasonically extracted at 50° C. for 1.5 hours, the extracts after two extractions are collected, the extracts are concentrated and freeze-dried for later use; the rest are consistent with example 1.

[0061] Comparative Example 3

[0062] The difference between Comparative Example 3 and Example 1 is that quinoa polypeptide is replaced with quinoa powder, and the rest is the same as Example 1.

[0063] Comparative Example 4

[0064] The difference between Comparative Example 4 and Example 1 is that the quinoa polypeptide in Example 1 is replaced by a quinoa polypeptide with a molecular weight ≥ 1 kDa.

[0065] Test Example 1

[0066] Silkworms at the 4th instar were selected and randomly divided into Example 1 group, Example 2 group, Example 3 group, Comparative Example 1 group, Comparative Example 2 group, Comparative Example 3 group, Comparative Example 4 group, and control group. The control group was fed only with normal mulberry leaves, and the other groups were fed with mulberry leaves with the additives described in Examples 1-3 and Comparative Examples 1-4 evenly spread on the surface (the mass of the additives was 0.4 of the mass of the mulberry leaves), and the silkworms were raised until they matured and cocooned, and the number of deaths and cocoon numbers of the silkworms were recorded. The experimental results are shown in Table 1.

[0067] Table 1

[0068] Group Number of tests Deaths Number of cocoons Control group 500 5 495 Example 1 500 2 498 Example 2 500 3 497 Example 3 500 3 497 Comparative Example 1 500 4 496 Comparative Example 2 500 3 497 Comparative Example 3 500 5 495 Comparative Example 4 500 4 496

[0069] It can be seen from the test results in Table 1 that, compared with the control group, there was no significant difference in the number of deaths and cocoons after feeding with the composite additives of Examples 1-3 of the present invention, indicating that the composite feed additive of the present invention does not affect the normal growth of silkworms.

[0070] Test Example 2

[0071] Silkworms at 4th instar were selected and randomly divided into Example 1 group, Example 2 group, Example 3 group, Comparative Example 1 group, Comparative Example 2 group, Comparative Example 3 group, Comparative Example 4 group and a control group.

[0072] The control group was fed only with normal mulberry leaves, and the other groups were fed with mulberry leaves evenly sprinkled with the additives described in Examples 1-3 and Comparative Examples 1-4 (the mass of the additives was 0.4 of the mass of the mulberry leaves) for 3 consecutive days; then, the silkworm Nosema was diluted to 1×10 6 spores / mL suspension, soaking mulberry leaves in the above suspension, taking out and drying after 10s, feeding silkworms of Example 1-3 group, Comparative Example 1-4 group and control group for 12h (subsequently no mulberry leaves treated with silkworm microsporidia were given), then the control group was fed only normal mulberry leaves, and the other groups were fed mulberry leaves with the additives described in Examples 1-3 and Comparative Examples 1-4 evenly spread on the surface, and the silkworms were raised to mature and cocooned, and the morbidity and mortality of the silkworms were counted during the period, and recorded in Table 2.

[0073] Table 2

[0074] Group Number of tests Incidence mortality rate Control group 60 83％ 77％ Example 1 60 5％ 2％ Example 2 60 8％ 5％ Example 3 60 7％ 3％ Comparative Example 1 60 38％ 23％ Comparative Example 2 60 27％ 15％ Comparative Example 3 60 25％ 13％ Comparative Example 4 60 12％ 8％

[0075] It can be seen from the test results in Table 2 that the morbidity and mortality of the silkworms in the control group after being treated with silkworm microsporidia are at a high level. Compared with the control group, the morbidity and mortality of the silkworms in Examples 1-3 of the present invention are significantly reduced, among which the morbidity of Example 1 is only 5% and the mortality is 2%. And it is lower than that of the comparative examples 1-4. It shows that the composite additive of the present invention can effectively reduce the morbidity and mortality of silkworms. Compared with Example 1, the preparation process of the Ficus Ficus extract in the comparative example 1 group is replaced by extraction with the root of Ficus Ficus, and the morbidity of microparticle disease is 38% and the mortality is 23%. The preparation process of the Ficus Ficus extract in the comparative example 2 is replaced by extraction with the fruit of Ficus Ficus, and the morbidity of microparticle disease is 27% and the mortality is 15%. It can be seen that the Ficus Ficus extract obtained from different parts of Ficus Ficus has obvious differences in the effects that can be finally achieved. In terms of preventing and treating microparticle disease, the effect of the extract obtained from the germinated Ficus Ficus seeds is better than that of the Ficus Ficus fruit extract, and the Ficus Ficus root extract is the worst. In comparative example 3, quinoa polypeptide was replaced with quinoa powder, and in comparative example 4, quinoa polypeptide with a molecular weight <1 kDa was replaced with quinoa polypeptide with a molecular weight ≥1 kDa. The incidence and mortality rates were higher than those in Example 1, indicating that quinoa polypeptide plays an important role in preventing and treating microparticle disease, and quinoa polypeptide with a small molecular weight has a better effect in additives.

[0076] In summary, the components in the composite additive of the present invention, especially the quinoa polypeptide and the Ficus Ficus pumila extract (germinated Ficus Ficus pumila seeds), can act synergistically to enhance the immunity of silkworms, reduce the occurrence of diseases, thereby improving the survival rate of silkworms and reducing the cost of silkworm farmers in the subsequent process.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. On the basis of the present invention, some modifications or replacements may be made thereto, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of protection claimed by the present invention.

Claims

1. A composite additive for improving the survival rate of silkworms, characterized in that: The invention comprises the following raw materials in parts by weight: 20-30 parts of aged zeolite powder, 1-5 parts of chitosan, 5-10 parts of Ficus pumila extract, 7-12 parts of quinoa polypeptide and 1-5 parts of trace elements.

2. A composite additive for improving the survival rate of silkworms according to claim 1, characterized in that: The preparation process of the Ficus pumila extract is as follows: sowing Ficus pumila seeds in the soil, controlling the temperature at 25-30°C and the relative humidity of the soil at 80-90%, collecting the germinated Ficus pumila seeds after 5-10 days, cleaning them, crushing them, adding them to an ethanol aqueous solution, heating and extracting them for a period of time, collecting the extract, concentrating the extract, and freeze-drying it for later use.

3. A composite additive for improving the survival rate of silkworms according to claim 1, characterized in that: The preparation process of the quinoa polypeptide is as follows: (1) washing quinoa seeds and drying them, adding petroleum ether and letting them stand for a period of time, removing the petroleum ether and then crushing them to obtain quinoa powder, adding α-amylase to hydrolyze them, and obtaining quinoa protein; (2) adding trypsin to the quinoa protein of step (1) for enzymatic hydrolysis; (3) After the enzymatic hydrolysis is completed, the supernatant is freeze-dried to obtain an enzymatic hydrolysis product, and the collected enzymatic hydrolysis product is separated using an ultrafiltration membrane to collect products with a molecular weight of less than 1 kDa for later use.

4. A composite additive for improving the survival rate of silkworms according to claim 1, characterized in that: The concentration of the α-amylase is 200-400 U / g.

5. A composite additive for improving the survival rate of silkworms according to claim 1, characterized in that: In step (1), the hydrolysis temperature is 55-65°C and the time is 2-4h.

6. A composite additive for improving the survival rate of silkworms according to claim 1, characterized in that: The concentration of trypsin is 400-600 U / g.

7. A composite additive for improving the survival rate of silkworms according to claim 1, characterized in that: In step (2), the enzymatic hydrolysis temperature is 33-37° C. and the time is 3-4 h.

8. The method for preparing the composite additive for improving the survival rate of silkworms according to any one of claims 1 to 7, characterized in that: The aged zeolite powder, chitosan, Ficus pumila extract, quinoa polypeptide and trace elements are weighed according to the above weight parts, and mixed thoroughly to obtain the product.

9. The method for preparing the composite additive for improving the survival rate of silkworms according to claim 8, characterized in that: The trace elements are prepared by mixing copper glycinate, iron glycinate, zinc lactate and manganese methionine in a mass ratio of 1:5:4:

3.

10. The method for preparing the composite additive for improving the survival rate of silkworms according to claim 8, characterized in that: The preparation of the aged zeolite powder comprises the following steps: calcining the zeolite at 1100-1200° C. for 2-4 hours, and then aging the zeolite at 30-35° C. for 8-10 days.