Method for breeding hermetia illucens larvae by using high-concentration organic wastewater and pre-digesting plant-based feed raw materials by hermetia illucens larvae through abdomen

Abstract

The invention belongs to the technical field of organic wastewater resource utilization, and discloses a method for breeding hermetia illucens larvae by using high-concentration organic wastewater and pre-digesting plant-based feed raw materials by the hermetia illucens larvae through the abdomen. The method comprises the following steps: collecting organic wastewater, adding the organic wastewater into a feed, inoculating a fermentation inoculant for fermentation, adding modified zeolite, folic acid and choline chloride into a fermentation product, uniformly stirring, and adding the organic wastewater to adjust the humidity of a mixture, thereby obtaining the feed, the obtained feed is used for feeding hermetia illucens larvae, and organic wastewater is added in the feeding process to keep the humidity of the feed. The organic wastewater does not need to be pretreated and is repeatedly utilized in feed preparation and feeding; the modified zeolite is added, so that the feed intake and conversion rate of the hermetia illucens larvae to high-concentration organic wastewater feed are improved, and the growth performance of the hermetia illucens larvae is improved; folic acid and choline chloride improve the fatty acid content of hermetia illucens bodies; and the produced insect sand with high protein and organic matters can be used as feed, so that the conversion from low-value wastewater to high-value products is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of resource utilization of organic wastewater, and in particular relates to a method for breeding black soldier fly larvae by utilizing high-concentration organic wastewater and for pre-digesting plant-based feed raw materials by the black soldier fly larvae through the abdomen. Background Art

[0002] Organic wastewater generally refers to wastewater with a COD of more than 2000 mg / L discharged from industries such as papermaking, leather and food processing. These wastewaters contain a large amount of organic matter such as carbohydrates, fats, proteins, cellulose, etc. If they are discharged directly, they will cause serious pollution. Food waste accounts for about 30%-50% of the global solid waste, and the BOD5 concentration of food wastewater separated from food waste is high, which can reach 50,000 mg / L or more, and the composition is complex. It is mainly composed of a large amount of soluble organic matter and suspended matter, rich in sugars, oils, proteins, amino acids, organic acids and various trace elements. It is both a valuable resource and a source of pollution. Because it contains extremely high moisture, organic matter and a large number of microorganisms, it is easy to rot, rancid, and produce stench, but it can be converted into new resources after proper treatment and processing. Oil is the main contributor to the COD / BOD5 value of food wastewater. Because it contains fatty acids, glycerol and other components, oil is not easy to biodegrade, which will seriously hinder the subsequent biological treatment process. In addition, other food processing processes also produce high-concentration wastewater, such as wastewater from dairy factories, fruit processing plants, bean product factories, breweries, starch saccharification plants, amino acid fermentation plants, organic acid fermentation plants, etc. In general, organic wastewater with high COD / BOD5 should be treated professionally, which requires complex processes, large investments, and high operating costs.

[0003] At present, the treatment of food waste mainly targets waste residues, such as landfill, incineration, aerobic composting, anaerobic fermentation, insect biotransformation, etc. Since the COD and BOD5 of organic wastewater can be as high as tens of thousands or hundreds of thousands, they are currently treated by anaerobic and aerobic treatment to produce biogas, and the treatment cost is high. For example, the traditional treatment of food wastewater is often to separate it into three phases of residual oil and water, and treat or discharge it as general domestic sewage, which not only increases the treatment cost of food wastewater, but also wastes the utilization of nutrients in food wastewater. The biological treatment methods disclosed in CN118558707A and CN117179126A generally use wastewater to filter out wastewater and only use waste residue as insect feed, which is easy to cause waste of organic matter in wastewater. The separated food wastewater is a high-concentration organic wastewater, and the COD can be as high as 100,000 (mg / L) or more, indicating that the water contains a large amount of organic pollution, which may include toxic and harmful organic compounds, which will have toxic effects on aquatic organisms, destroy the aquatic ecological balance, and threaten human health and drinking water. When wastewater containing organic matter is used directly to feed livestock, poultry or fish, the high concentration of COD will lead to a decrease in their feed intake, the harmful substances contained in the wastewater will destroy their immunity, and the nutrients in the wastewater itself are not enough to meet the animals' nutritional needs, resulting in generally low daily weight gain and survival rate.

[0004] The role of resource insects, such as edible insects, in the treatment of waste containing organic matter has become a research hotspot. After being digested and degraded by insects, organic matter can be converted into high value-added products, realizing efficient utilization of resource cycles. Therefore, how to reasonably recycle high-concentration COD / BOD5 organic wastewater, transform it into resource substances, reduce treatment costs and increase economic conversion value is of great significance to the resource utilization of organic wastewater and improve the ecological environment. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, one of the purposes of the present invention is to provide a method for breeding black soldier fly larvae using high-concentration organic wastewater and pre-digesting plant-based feed raw materials by the black soldier fly larvae.

[0006] Another object of the present invention is a black soldier fly feed prepared based on high-concentration organic wastewater.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for breeding black soldier fly larvae using high-concentration organic wastewater comprises the following steps:

[0009] S1. Collect high-concentration organic wastewater, add the organic wastewater to the plant-based feed to make the moisture content reach more than 60%, and then add the fermentation agent for fermentation to obtain a fermentation product; then add modified zeolite, folic acid and choline chloride to the fermentation product, stir evenly, and obtain feed; the added organic wastewater can not only adjust the humidity of the mixture, but also is rich in organic nutrients, and thus obtain feed;

[0010] S2. Feed the black soldier fly larvae with the feed obtained in step S1. During the feeding process, the organic wastewater described in step S1 is directly supplemented according to the evaporation and content of water to maintain the moisture of the feed.

[0011] Furthermore, the COD or BOD5 value of the high-concentration organic wastewater in step S1 is greater than 50,000 mg / L.

[0012] Furthermore, the organic wastewater in step S1 comes from three-phase separation wastewater from table waste, and can also be high-concentration wastewater generated in other food processing processes, such as wastewater generated by dairy factories, fruit processing factories, bean product factories, starch saccharification factories, breweries, amino acid and organic acid fermentation factories, etc.

[0013] Furthermore, the amount of high-concentration organic wastewater added in step S1 is such that the moisture content of the plant-based feed reaches 65-85%, while supplementing rich nutrients, including carbohydrates, fats, proteins, amino acids, etc.

[0014] Furthermore, the plant-based feed in step S1 can be selected from soybean meal, rapeseed meal, cottonseed meal, peanut meal, sunflower seed meal, palm kernel meal, coconut meal, dry and wet distiller's grains, DDGS, Chinese medicine residues, and other plant raw materials rich in nutrients such as fiber, sugars, starch, fat and protein.

[0015] The present invention uses plant-based feed with high fiber content as a carrier. The plant-based feed not only contains sugar, starch, protein, and fat; and the fiber will generate a large amount of fermentation heat during the fermentation and black soldier fly breeding process, which will evaporate the waste water. Therefore, organic waste water must be added during the breeding process to achieve the purpose of concentrating and evaporating water, thereby achieving waste water reduction; the concentrated waste water is rich in sugar, starch, protein, fat, etc., and provides excellent nutrition for the growth and development of black soldier fly larvae.

[0016] The present invention directly utilizes high-concentration organic wastewater as one of the nutrients, mixes it with the above-mentioned plant-based feed, and directly uses it for black soldier fly larvae breeding after fermentation for a few days, creating a new method for recycling and treating high-concentration organic wastewater. Each black soldier fly larva is a biochemical reactor. After being digested and degraded by the insect's abdomen, the organic wastewater can be converted into high-value-added products, thereby realizing the efficient utilization of waste resource cycles.

[0017] Furthermore, the modified zeolite described in step S1 is obtained by a modification method of reducing the silicon-aluminum ratio, dissolving KCl and NaOH in water, dissolving Al(OH)3 in hot KCl and NaOH solutions, adding natural zeolite to the solution, stirring at room temperature for 3-5 hours, separating the solution, and washing with water until neutral. After evaporation, the solid is calcined at 350-500°C for 1.5-2 hours. In the research of the present invention, the modified zeolite can increase the survival rate of black soldier fly larvae, feed intake and promote the absorption and conversion of nutrients. It may be that compared with natural zeolite, the modified zeolite changes the adsorption characteristics and adsorption effect of zeolite.

[0018] Furthermore, the fermentation agent in step S1 is one or a mixture of yeast, Bacillus subtilis, and lactic acid bacteria.

[0019] Furthermore, the amount of the fermentation agent in step S1 is 0.5% to 0.8% of the mass of the plant-based feed.

[0020] Furthermore, the fermentation temperature in step S1 is 28-35° C., and the fermentation time is 1-5 days, which is adjusted according to the temperature and pH value of the raw materials.

[0021] Furthermore, the feed in step S1 includes 500-700 parts of fermentation products, 14-28 parts of modified zeolite, 0.00005-0.0003 parts of folic acid, and 0.12-0.16 parts of choline chloride; and organic wastewater is added to adjust the humidity of the feed to 60-80%.

[0022] Furthermore, in step S2, the black soldier fly larvae are selected to be 5-6 days old.

[0023] Furthermore, in step S2, the humidity of the feed is maintained at 60-80%.

[0024] The present invention also provides a black soldier fly larvae feed prepared by the above method based on recycling high-concentration organic wastewater. The components of the feed include plant-based feed, organic wastewater, fermentation bacteria, modified zeolite, folic acid and choline chloride.

[0025] The present invention also provides the use of the method of feeding black soldier fly larvae with high-concentration organic wastewater in improving the growth performance of black soldier flies, and the growth performance includes weight gain, survival rate, feed conversion rate, etc. In addition, it is also found through research that feeding with the black soldier fly feed prepared by the present invention can also increase the content of fatty acids in the black soldier fly body, especially the content of lauric acid.

[0026] Furthermore, the present invention also claims to protect the insect sand collected after feeding in the above step S2 and processed by the black soldier fly, and the above insect sand mainly refers to the insect egg shells, the residues after the larvae molt, the insect excrement during the feeding process and other substances after the black soldier fly's abdominal processing. The obtained insect sand is used for breeding livestock and poultry, which can improve the adverse effects of the use of miscellaneous meal raw materials in the livestock and poultry breeding process, such as production performance, mortality rate, etc.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The present invention does not require pretreatment of high-concentration COD / BOD5 organic wastewater, and can be reused multiple times in feed preparation. It can be directly added to feed black soldier fly larvae, thereby achieving resource recovery and utilization of high-concentration COD / BOD5 organic wastewater and improving the ecological environment, and the process is simple.

[0029] (2) The present invention improves the feeding conversion and tolerance of black soldier fly larvae to feed based on high-concentration COD / BOD5 organic wastewater by adding modified zeolite to feed black soldier fly larvae, and can significantly improve the growth performance of black soldier flies, including survival rate, weight gain and feed conversion rate.

[0030] (3) While improving the growth performance, the present invention increases the fatty acid content of the black soldier fly body by adding folic acid and choline chloride, especially the lauric acid content; the produced high-protein and organic insect sand can be used to produce chicken feed, pig feed, aquatic feed and herbivorous animal feed, and the insect feces can be directly used as feed; a higher economic value is achieved, completing the transformation from low-value wastewater to high-value products. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention below will provide a detailed and comprehensive description of the technical solutions of the present invention. It should be noted that the embodiments provided represent only a part of the present invention, not all of it. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Unless otherwise specified, the experimental methods used in the examples of the present invention are all conventional methods; the materials, reagents, etc. used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0033] The modified zeolite adopts the conventional method: dissolve KCl and NaOH in water, dissolve Al(OH)3 in hot KCl and NaOH solution (molar ratio 1:1:1), add natural zeolite to the solution, stir at room temperature for 3 hours, separate the solution, wash with water until neutral. After evaporation, put the solid into 500℃ for calcination for 1.5 hours.

[0034] The choline chloride content (%) is 60%, purchased from Wuhan Jiyesheng Chemical Co., Ltd.; the auxiliary bacterial agent is purchased from the China Industrial Microorganism Culture Collection Administration Center, the Chinese name is Yarrowia lipolytica, and the number is CICC31829; purchased from the China Industrial Microorganism Culture Collection Administration Center, the Chinese name is Bacillus subtilis, and the number is CICC10446; purchased from the China Industrial Microorganism Culture Collection Administration Center, the Chinese name is Lactobacillus acidophilus, and the number is CICC6082; the above-mentioned bacterial agents are not limited to the above-mentioned numbers, and those skilled in the art can use the bacteria from other sources.

[0035] In some embodiments and comparative examples of the present invention, the organic wastewater uses food wastewater, which comes from a restaurant kitchen waste treatment station in Baiyun District, Guangzhou City, Guangdong Province. The embodiments and comparative examples of the present invention use the same batch of food waste for optimization experiments. After removing impurities such as plastics and metals, the garbage is crushed with a grinder, and then the food wastewater is separated and collected using a three-phase separation device. The COD of the food wastewater is tested to be 154620 mg / L. In some embodiments (such as Example 5), the organic wastewater uses dairy processing wastewater, which is a high-concentration wastewater generated during the production process of a dairy enterprise in Shaanxi Province. The BOD5 of the wastewater is tested to be 55340 mg / L.

[0036] Example 1

[0037] A method for breeding black soldier flies using high-concentration organic wastewater mainly comprises the following steps:

[0038] (1) Collect food waste, remove impurities such as plastic and metal that cannot be eaten by black soldier flies, use a crusher to crush the waste into 10-mesh particles, and then use a three-phase separation device to separate and collect food wastewater;

[0039] (2) Adding food wastewater to peanut meal to make the moisture content of peanut meal reach 65%, taking yeast (purchased from China Industrial Microbiological Culture Collection Management Center, Chinese name Yarrowia lipolytica, number CICC31829) with a mass of 0.6% of peanut meal, and fermenting at a temperature of 35°C for 7 days;

[0040] (3) adding modified zeolite, folic acid and choline chloride to the fermentation product and stirring evenly, the mixture includes 700 parts of fermentation product, 28 parts of modified zeolite, 0.0003 parts of folic acid and 0.16 parts of choline chloride; adding waste water to adjust the humidity of the mixture to 75%, thereby obtaining feed;

[0041] (4) The obtained feed is fed to 6-day-old larvae of black soldier flies. During the feeding process, water evaporation and consumption will occur. Wastewater from the meal is added every day to keep the moisture of the feed at 75%.

[0042] Example 2

[0043] A method for breeding black soldier fly larvae using high-concentration organic wastewater mainly comprises the following steps:

[0044] (1) Collect food waste, remove impurities such as plastic and metal that cannot be eaten by black soldier flies, use a crusher to crush the waste into 10-mesh particles, and then use a three-phase separation device to separate and collect food wastewater;

[0045] (2) adding food wastewater to peanut meal to make the moisture content of peanut meal reach 70%, taking 0.5% of the weight of peanut meal of Bacillus subtilis (purchased from China Industrial Microbiological Culture Collection Management Center, Chinese name Bacillus subtilis, number CICC10446), and fermenting at a temperature of 35°C for 7 days;

[0046] (3) adding modified zeolite, folic acid and choline chloride to the fermentation product, stirring evenly, adding wastewater to adjust the humidity of the mixture to 80%, and obtaining a feed, wherein the feed comprises 600 parts of the fermentation product, 22 parts of the modified zeolite, 0.0001 parts of folic acid, and 0.12 parts of choline chloride;

[0047] (4) The obtained feed is fed to 6-day-old larvae of black soldier flies. During the feeding process, water evaporation and consumption will occur. Wastewater from meals is added every day to keep the moisture of the feed at 80%.

[0048] Example 3

[0049] A method for breeding black soldier fly larvae using high-concentration organic wastewater mainly comprises the following steps:

[0050] (1) Collect food waste, remove impurities such as plastic and metal that cannot be eaten by black soldier fly larvae, use a crusher to crush the waste into 10-mesh particles, and then use a three-phase separation device to separate and collect food wastewater;

[0051] (2) Adding food wastewater to peanut meal to make the moisture content of peanut meal reach 75%, taking yeast (purchased from China Industrial Microbiological Culture Collection Management Center, Chinese name Yarrowia lipolytica, number CICC31829) with a mass of 0.8% of the peanut meal, and fermenting at a temperature of 35°C for 7 days;

[0052] (3) adding modified zeolite, folic acid and choline chloride to the fermentation product, stirring evenly, adding wastewater to adjust the humidity of the mixture to 70%, and obtaining a feed, wherein the feed comprises 500 parts of the fermentation product, 14 parts of the modified zeolite, 0.00005 parts of folic acid, and 0.14 parts of choline chloride;

[0053] (4) The obtained feed is fed to 5-day-old larvae of black soldier flies. During the feeding process, water evaporation and consumption will occur. Wastewater from the meal is added every day to keep the moisture of the feed at 70%.

[0054] Example 4

[0055] A method for breeding black soldier fly larvae using high-concentration organic wastewater mainly comprises the following steps:

[0056] (1) Collect food waste, remove impurities such as plastic and metal that cannot be eaten by black soldier flies, use a crusher to crush the waste into 10-mesh particles, and then use a three-phase separation device to separate and collect food wastewater;

[0057] (2) adding food wastewater to peanut meal to make the moisture content of peanut meal reach 75%, taking lactic acid bacteria (purchased from China Industrial Microbiological Culture Collection Management Center, Chinese name Lactobacillus acidophilus, number CICC6082) with a mass of 0.7% of peanut meal, and fermenting at a temperature of 35°C for 7 days;

[0058] (3) adding modified zeolite, folic acid and choline chloride to the fermentation product, stirring evenly, adding wastewater to adjust the humidity of the mixture to 75%, and obtaining a feed, wherein the feed comprises 700 parts of the fermentation product, 24 parts of the modified zeolite, 0.0002 parts of folic acid, and 0.15 parts of choline chloride;

[0059] (4) The obtained feed is fed to 5-day-old larvae of black soldier flies. During the feeding process, water evaporation and consumption will occur. Wastewater from the meal is added every day to keep the moisture of the feed at 75%.

[0060] Example 5

[0061] A method for breeding black soldier fly larvae using high-concentration organic wastewater mainly comprises the following steps:

[0062] (1) collecting dairy processing wastewater; adding dairy processing wastewater to peanut meal to make the moisture content of peanut meal reach 65%, taking yeast (purchased from China Industrial Microbiological Culture Collection Management Center, Chinese name Yarrowia lipolytica, number CICC31829) with a mass of 0.6% of the peanut meal, and fermenting at a temperature of 35°C for 7 days;

[0063] (2) adding modified zeolite, folic acid and choline chloride to the fermentation product and stirring evenly, the mixture includes 700 parts of the fermentation product, 28 parts of the modified zeolite, 0.0003 parts of folic acid and 0.16 parts of choline chloride; adding dairy processing wastewater to adjust the humidity of the mixture to 80%, thereby obtaining a feed;

[0064] (3) The obtained feed is used to feed 6-day-old larvae of black soldier flies. During the feeding process, water evaporation and consumption will occur. Dairy processing wastewater is added every day to keep the feed moisture at 80%.

[0065] Comparative Example 1

[0066] (1) tap water was added to the peanut meal to make the moisture content of the peanut meal reach 65%, and yeast (purchased from China Industrial Microbiological Culture Collection Administration Center, Chinese name Yarrowia lipolytica, number CICC31829) with a weight of 0.6% of the peanut meal was fermented at 35° C. for 7 days;

[0067] (2) adding modified zeolite, folic acid and choline chloride to the fermentation product and stirring evenly, the mixture includes 700 parts of the fermentation product, 28 parts of the modified zeolite, 0.0003 parts of folic acid and 0.16 parts of choline chloride; adding tap water to adjust the humidity of the mixture to 75%, thereby obtaining a feed;

[0068] (3) The obtained feed is fed to 6-day-old black soldier fly larvae. During the feeding process, water evaporation and consumption will occur. Tap water is added every day to maintain the feed humidity at 75%.

[0069] Compared with Example 1, the difference of Comparative Example 1 is that tap water is used instead of food waste water.

[0070] Comparative Example 2

[0071] Compared with Example 1, the difference of Comparative Example 2 is that natural zeolite is added in step (3) instead of modified zeolite, and other operations and parameters remain unchanged.

[0072] Comparative Example 3

[0073] Compared with Example 1, the difference of Comparative Example 3 is that folic acid is not added in step (3), and other operations and parameters remain unchanged.

[0074] Comparative Example 4

[0075] Compared with Example 1, the difference of Comparative Example 4 is that in step (3), choline chloride is replaced by nicotinic acid, and other operations and parameters remain unchanged.

[0076] Experiment on feeding black soldier fly larvae and analysis of the results

[0077] The control group (CK) was a nursery feed (conventional wheat bran + soybean meal + tap water). Healthy, 6-day-old Wuhan strain black soldier flies of similar size were selected and divided into 10 groups (see Table 1), with 200 in each group. Each group of feed must have residual feed every day to ensure sufficient insect food, and the breeding environment temperature was maintained at 28°C and the relative humidity of the air was 75%. During the breeding process, the amount of live insects and the weight of residual feed in the basin after 13 days of breeding were recorded, and the weight of each group of black soldier flies before and after breeding was recorded. The black soldier flies were then freeze-dried, crushed, and uniformly extracted with Soxhlet (n-hexane extract), and the content of fatty acids in the black soldier flies was determined and analyzed by GC-MS (see Table 2).

[0078] The calculation methods of each indicator are as follows:

[0079] (1) Total weight gain of black soldier fly larvae (kg) = A2-A1,

[0080] A2 is the total weight of black soldier fly larvae after feeding, and A1 is the total weight of black soldier fly larvae before feeding;

[0081] (2) Larval survival rate = number of live larvae at the end of the test / number of live larvae at the beginning of the test * 100%;

[0082] (3) Feed conversion rate = insect weight gain / (total amount of feed added-feed surplus)*100%;

[0083] The test results of all embodiments and comparative examples are shown in Table 1.

[0084] Table 1

[0085]

[0086]

[0087] Table 2 Comparison of some fatty acid components and contents (%)

[0088] Example 1 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 CK group Stearic acid 2.57 2.79 2.36 2.15 1.79 1.84 4.08 Lauric acid 34.43 33.82 23.55 26.06 22.81 14.59 11.81 Pentadecanoic acid 0.18 0.21 0.14 0.11 0.17 0.24 0.074 Myristic acid 5.89 5.16 5.73 4.35 5.24 6.05 0.26 Oleic acid 12.38 13.74 11.75 10.48 11.33 10.59 24.15 Palmitic acid 14.43 13.45 15.98 15.25 13.12 16.94 18.46 Linoleic acid 17.85 18.40 17.04 18.67 18.28 24.65 20.39

[0089] Results Analysis

[0090] As shown in Tables 1 and 2, the feed prepared by the embodiment of the present invention is fed to black soldier fly larvae, and has significant advantages in terms of improving growth performance such as weight gain, survival rate, feed conversion rate, and improving the fatty acid composition and content of black soldier fly larvae. Moreover, this study shows that compared with the CK group, the fatty acid composition of black soldier fly larvae changes due to the different feed bases and feeding conditions, especially the composition of lipid substances or proteins and carbohydrates in the feed. The present invention regulates the fatty acid composition of the feed by adjusting the feed formula and feeding conditions, and has excellent effects in improving the fatty acid content of the insect body.

[0091] Relative to Example 1, in Comparative Example 1, tap water was used instead of wastewater to prepare feed and add feed, and the weight gain and feed conversion rate of the fed black soldier fly larvae were significantly lower than those in Example 1. Most importantly, there was no significant difference in the survival rate of the larvae after switching to tap water, indicating that in the technical scheme of the present invention, black soldier flies can convert and recycle toxic and harmful substances in wastewater in the abdomen, and the batch addition of wastewater will not have a negative impact on the survival rate of black soldier flies larvae. And compared with tap water, wastewater contains a large amount of fat, protein and other substances that increase the weight gain, feed conversion rate and fatty acid content of black soldier flies. The survival rate, weight gain, feed conversion rate and fatty acid content of black soldier flies in Comparative Example 2 all decreased significantly, which may be because the modified zeolite in the embodiment can specifically adsorb harmful substances in wastewater, promote the feeding of black soldier flies larvae, thereby improving the survival rate, weight gain and feed conversion rate of black soldier flies larvae, and promoting fatty acid conversion. In comparative example 3, when folic acid was not added, the fatty acid content of the insect body decreased significantly, indicating that folic acid can promote the conversion of fatty acids, and at the same time improve the feeding and conversion of the black soldier fly larvae to the feed prepared by recycling the wastewater of the present invention. Comparative example 4 uses nicotinic acid and folic acid together, resulting in a decrease in the fatty acid content of the insect body, indicating that the combined effect of folic acid and choline chloride promotes the conversion of fatty acids by black soldier flies, especially the significant difference in lauric acid content, which may have the function of enhancing the immunity of larvae, protecting larvae from the influence of lipid oxidation, and making black soldier flies have a stronger tolerance to the environment of higher concentration of organic wastewater.

[0092] The above results show that the feed provided by the present invention has achieved good results in feeding black soldier fly larvae. In addition, the present invention uses high-concentration COD or BOD5 organic wastewater instead of tap water, and mixes and prepares feed multiple times. There is no need to perform industrial treatment such as coagulation on the organic wastewater. This not only achieves the recycling of high-concentration organic wastewater, but also improves the growth performance and fatty acid content of black soldier flies, reduces breeding costs, and improves economic benefits.

[0093] Table 3

[0094] project Example 1 Example 2 Example 3 Example 4 Example 5 CK group Crude protein % 28.57 28.83 27.65 26.49 27.03 22.84 Crude ash % 46.82 45.12 47.45 47.82 46.35 32.46 pH 6.83 6.95 6.87 6.80 6.96 6.67 Organic matter% 75.80 74.56 74.98 73.53 73.85 67.41 Total nitrogen % 4.85 4.67 4.53 4.39 4.61 3.74 Total phosphorus % 1.79 1.87 1.71 1.68 1.52 1.26 Total Potassium % 0.84 0.77 0.69 0.72 0.58 0..35

[0095] On the other hand, the effect of high-concentration organic wastewater on the nutritional content of insect feces is shown in Table 3. After 15-20 days of breeding black soldier flies with the feed prepared by the present invention, the moisture content of the insect feces produced is controlled at about 40%-50%, which is conducive to the separation of the insect body and the insect feces; after the insects are collected, the remaining insect feces are fermented to produce animal feed or raw materials with high protein and organic acid that have been pre-digested by the black soldier flies. It can be used to produce chicken feed, pig feed, aquatic feed and herbivorous animal feed. That is, the present invention can also realize the direct feed of insect feces.

[0096] Implementation case 1: Experiment on raising laying hens with black soldier fly sand as feed:

[0097] (I) Test materials and test methods

[0098] 1 Test materials

[0099] 1.1 Experimental animals

[0100] 360 healthy Jinghong No. 1 laying hens of similar weight and egg production rate at 40 weeks of age were selected and randomly divided into 3 treatment groups, with 6 replicates in each treatment group and 20 hens in each replicate. A fully enclosed environmentally controlled cage was used to raise 4 laying hens in each metal cage. During the experiment, the hens were allowed to eat and drink freely, and the feces were cleaned daily and disinfected regularly to keep the house ventilated, clean, dry and hygienic. The formal experiment began after 1 week of pre-feeding, and the formal experiment lasted for 28 days.

[0101] The control group was fed a corn-soybean meal-based basal diet (see Table 4); the peanut meal group and the insect sand group were fed a basal diet with peanut meal or peanut meal fermented insect sand (based on step (4) of Example 1: the insect sand obtained by feeding the obtained feed to 6-day-old black soldier fly larvae) added to replace 30% of the soybean meal. The amount of feed added, mortality rate, egg production rate and egg weight were recorded every day, the feed intake was counted every week, and the production performance and egg quality of laying hens were recorded, observed and measured.

[0102] 1.2 Main instruments and equipment

[0103] EFR-01 eggshell strength tester, ETG-1061 eggshell thickness tester, EA-01 multifunctional egg quality analyzer, BSA2201-CW electronic precision balance, MA160-1CN infrared moisture meter, desktop high-speed refrigerated centrifuge, DW-86L626 ultra-low temperature refrigerator, DHG-9145A blast drying oven, HH-2 digital display constant temperature water bath, BF-10 small high-speed crusher, SCIENTZ-50YG / A freeze dryer.

[0104] Table 4 Nutritional standard composition of basic diet

[0105]

[0106]

[0107] 2 Test methods

[0108] 2.1 Determination of production performance

[0109] Average daily feed intake: Record the feed intake of each group every week and calculate the average daily feed intake. Average daily feed intake = total feed intake / number of days / number of laying hens in stock.

[0110] Average egg weight: record the total egg weight of each group every day and calculate the average egg weight per day. Daily average egg weight = daily total egg weight / daily number of eggs produced.

[0111] Average egg production rate: record the number of eggs laid by each group and the number of laying hens in stock every day, and calculate the average egg production rate per day. Daily egg production rate = daily egg production / number of laying hens in stock.

[0112] Feed-egg ratio: record the total egg weight and feed consumption of each group every day, and calculate the feed-egg ratio of each group. Feed-egg ratio = feed consumption / total egg weight.

[0113] Mortality rate: record the number of dead and culled chickens in each group every day and calculate the mortality rate of each group. Mortality rate = number of dead and culled chickens / number of chickens in the house.

[0114] 2.2 Determination of egg quality

[0115] The eggshell strength was measured using the EFR-01 eggshell strength tester. The egg was placed vertically on the tester with the blunt end facing upwards. The unit was set to kg / cm 2 .

[0116] The eggshell thickness was measured using an ETG-1061 eggshell thickness tester. The thickness at the tip, middle and blunt end of the egg was measured to calculate the average eggshell thickness.

[0117] Egg weight, yolk color, albumen height and Haugh unit were measured using the EA-01 multifunctional egg quality analyzer. After cracking the eggs, the fresh eggs were placed in the center of the analyzer tray.

[0118] (II) Test results and analysis

[0119] 1 Effects of peanut meal and fermented insect sand on production performance of laying hens

[0120] Table 5 Production performance

[0121] project Control group Peanut meal group Insect Sand Group Average daily feed intake (g) 114.64 113.87 116.18 Average egg weight (g) 61.76 60.23 61.68 Average egg production rate (%) 83.14 82.33 83.56 Feed to Egg Ratio 2.23 2.30 2.25 Mortality rate (%) 3.89 5.01 3.27

[0122] The test results are shown in Table 5. Compared with the control group, the peanut meal group was adversely affected in terms of feed intake, mortality rate and other indicators due to the influence of miscellaneous meal, while peanut meal fermented insect sand increased the average daily feed intake of laying hens and reduced the mortality rate, and had no significant effect on the average egg weight and average egg production rate. The above results show that peanut meal fermented insect sand can improve the decline in production performance caused by peanut meal feeding laying hens and reduce the mortality rate.

[0123] 2 Effects of peanut meal and fermented insect sand on egg quality

[0124] Table 6 Egg quality

[0125] project Control group Peanut meal group Insect Sand Group Egg weight (g) 61.79 60.72 61.64 <![CDATA[Eggshell strength (kg / cm 2 )]]> 3.55 3.67 3.69 Eggshell thickness (mm) 0.37 0.39 0.39 Yolk color 7.82 8.01 7.99 Protein height (mm) 6.83 6.92 7.12 Haugh unit 82.03 82.95 83.94

[0126] The test results are shown in Table 6. Compared with the control group, peanut meal fermented with insect sand increased the eggshell strength, yolk color, albumen height and Haugh unit of laying hens, but had no significant effect on egg weight and eggshell thickness. The above results show that peanut meal fermented with insect sand can improve eggshell quality and the freshness of eggs.

[0127] Implementation Case 2: Experiment on raising broiler chickens using black soldier fly sand as feed:

[0128] (I) Test materials and test methods

[0129] 1 Test materials

[0130] 1.1 Experimental animals

[0131] 360 healthy Hubbard broilers of 1 day old were selected and randomly divided into 3 treatment groups, each with 6 replicates and 20 chickens in each replicate. A fully enclosed environment-controlled cage chicken house was used, and 4 broilers were raised in each metal cage. During the experiment, they were allowed to eat and drink freely, and the feces were cleaned daily and disinfected regularly to keep the house ventilated, clean, dry and sanitary. The experimental period was 42 days. The control group was fed a corn-soybean meal-based basal diet (composition is shown in Table 7), which was consistent with the treatment in Implementation Case 1, and peanut meal and peanut meal fermented insect sand were added to replace 30% of the soybean meal, respectively, and named as the peanut meal group and the insect sand group. The amount of feed added and the mortality rate were recorded every day, the feed intake and body weight were counted weekly, and the production performance and slaughter performance of broilers were recorded, observed and measured.

[0132] 1.2 Main instruments and equipment

[0133] BSA2201-CW electronic precision balance, MA160-1CN infrared moisture meter, desktop high-speed refrigerated centrifuge, DW-86L626 ultra-low temperature refrigerator, DHG-9145A blast drying oven, HH-2 digital display constant temperature water bath, BF-10 small high-speed pulverizer, SCIENTZ-50YG / A freeze dryer.

[0134] Table 7 Basic diet composition

[0135]

[0136]

[0137] 2 Test methods

[0138] 2.1 Determination of production performance

[0139] Average daily feed intake: Record the feed intake of each group every week and calculate the average daily feed intake. Average daily feed intake = total feed intake / number of days / number of broilers in stock.

[0140] Average daily weight gain: Record the weight of each group every week and calculate the average daily weight gain. Average daily weight gain = (final weight - initial weight) / number of test days.

[0141] Feed-to-weight ratio: Record the weight gain and feed consumption of each group every week and calculate the feed-to-weight ratio of each group. Feed-to-weight ratio = average daily feed intake / average daily weight gain.

[0142] Mortality rate: record the number of dead and culled chickens in each group every day and calculate the mortality rate of each group. Mortality rate = number of dead and culled chickens / number of chickens in the house.

[0143] 2.2 Determination of slaughter performance

[0144] At the end of the experiment, 10 broilers were randomly selected from each group for slaughter, and the slaughter rate, semi-eviscerated rate and full-eviscerated rate were calculated. Live weight: the weight of broilers fasted for 12 hours before slaughter. Carcass weight: the weight after removing feathers, leg cuticles and toe shells after bleeding. Semi-eviscerated weight: the weight of the carcass after removing the trachea, esophagus, spleen, pancreas, gallbladder, crop, reproductive organs and intestines. Full-eviscerated weight: the weight of the semi-eviscerated weight after removing the heart, liver, kidney, gizzard, glandular stomach, fat, head and feet.

[0145] Dressing percentage = carcass weight / live weight

[0146] Eviscerated rate = Eviscerated weight / live weight

[0147] Eviscerated rate = Eviscerated weight / live weight

[0148] (II) Test results and analysis

[0149] 1 Effects of peanut meal and fermented insect sand on broiler production performance

[0150] Table 8 Production performance

[0151] project Control group Peanut meal group Insect Sand Group Average daily feed intake (g) 108.89 108.04 108.72 Average daily weight gain (g) 65.82 64.89 65.72 Material weight ratio (g) 1.65 1.67 1.65 Mortality rate (%) 3.45 3.53 3.14

[0152] The test results are shown in Table 8. Compared with the control group, peanut meal fermented with insect sand reduced the mortality rate of broilers, and had no significant effect on the average daily feed intake and average daily weight gain. The above results show that peanut meal fermented with insect sand can improve the decline in production performance caused by peanut meal feeding broilers and reduce the mortality rate.

[0153] 2 Effects of peanut meal and fermented insect sand on the slaughter performance of broiler chickens

[0154] Table 9 Slaughter performance

[0155] project Control group Peanut meal group Insect Sand Group Slaughter rate (%) 88.70 87.38 90.36 Half-eviscerated rate (%) 83.21 82.44 83.47 Eviscerated rate (%) 64.85 62.97 65.03

[0156] The test results are shown in Table 9. Compared with the control group, peanut meal fermented with insect sand increased the slaughter rate of broilers, and had no significant effect on the half-eviscerated rate and the full-eviscerated rate. The above results show that, combined with the comparison of the three groups of experiments, peanut meal fermented with insect sand can improve the decline in slaughter performance caused by peanut meal feeding broilers.

[0157] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation methods of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for breeding black soldier fly larvae using high-concentration organic wastewater, characterized in that: The following steps are involved: S1. Collect organic wastewater, add organic wastewater to plant-based feed to make the moisture content reach more than 60%, and connect fermentation bacteria to ferment to obtain a fermentation product; then add modified zeolite, folic acid and choline chloride to the fermentation product, stir evenly, and obtain feed; S2. Feed the black soldier fly larvae with the feed obtained in step S1. During the feeding process, the organic wastewater described in step S1 is directly supplemented according to the evaporation and content of water to maintain the moisture of the feed.

2. The method for breeding black soldier fly larvae using high-concentration organic wastewater according to claim 1, characterized in that: The COD or BOD5 in the organic wastewater in step S1 is greater than 50000 mg / L.

3. The method for breeding black soldier fly larvae using high-concentration organic wastewater according to claim 1, characterized in that: The organic wastewater in step S1 is selected from a mixture of one or more of table wastewater, dairy processing wastewater, fruit processing wastewater, soybean processing wastewater, brewing wastewater, starch saccharification wastewater, and amino acid and organic acid fermentation wastewater.

4. The method for breeding black soldier fly larvae using high-concentration organic wastewater according to claim 1, characterized in that: The amount of organic wastewater added in step S1 is such that the moisture content of the plant-based feed reaches 65-85%.

5. The method for breeding black soldier fly larvae using high-concentration organic wastewater according to claim 1, characterized in that: The plant-based feed described in S1 is selected from soybean meal, rapeseed meal, cottonseed meal, peanut meal, sunflower seed meal, palm kernel meal, coconut meal, dry and wet distiller's grains, DDGS, traditional Chinese medicine residues, and other plant raw materials rich in fiber and protein.

6. The method for breeding black soldier fly larvae using high-concentration organic wastewater according to claim 1, characterized in that: The modified zeolite in step S1 is obtained by a modification method of reducing the silicon-aluminum ratio. KCl and NaOH are dissolved in water, Al(OH)3 is dissolved in hot KCl and NaOH solutions, natural zeolite is added to the solution, stirred at room temperature for 3 to 5 hours, the solution is separated, washed with water to neutrality, and after evaporation, the solid is placed in 350 to 500°C for calcination for 1.5 to 2 hours.

7. The method for breeding black soldier fly larvae using high-concentration organic wastewater according to claim 1, characterized in that: The fermentation agent in step S1 is one or a mixture of yeast, Bacillus subtilis and lactic acid bacteria.

8. The method for breeding black soldier fly larvae using high-concentration organic wastewater according to claim 1, characterized in that: The dosage of the fermentation agent in step S1 is 0.5% to 0.8% of the mass of the plant-based feed.

9. The method for breeding black soldier fly larvae using high-concentration organic wastewater according to claim 1, characterized in that: The feed in step S1 includes 500-700 parts of fermentation products, 14-28 parts of modified zeolite, 0.00005-0.0003 parts of folic acid, 0.12-0.16 parts of choline chloride, and organic wastewater is added to adjust the humidity of the feed to 60-80%.

10. Use of the method according to any one of claims 1 to 9 in improving the growth performance and fatty acid content of black soldier fly larvae, and use of the insect sand obtained by the method in improving the adverse effects caused by the use of miscellaneous meal in livestock and poultry breeding processes.

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