Fermented feed silkworm excrement as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of aquatic feed and aquaculture, and particularly relates to fermented feed silkworm excrement as well as a preparation method and application thereof. The fermented silkworm excrement for breeding the feed is prepared by taking the silkworm excrement for breeding the feed, the soybean meal, the wheat bran, the fermentation strain, the carbon source and the inorganic salt as raw materials, and compared with unfermented raw materials and silkworm excrement for breeding the fermented mulberry leaves, the fermented silkworm excrement for breeding the feed prepared by fermenting the raw materials contains less antinutritional factors; according to the present invention, the content of nutrients such as crude protein, crude ash, crude fat, total amino acid and the like is increased, the feed coefficient is effectively reduced, and the feed can be well applied to aquatic feed preparation and freshwater fish culture, can effectively improve the growth performance and the immune activity of freshwater fish, and can reduce the blood sugar and the blood fat content of freshwater fish.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic feed and aquaculture, and particularly relates to a fermented feed for silkworm litter, a preparation method and application thereof. Background Art

[0002] Largemouth bass, also known as California bass, belongs to the order Perciformes, family Heliothisidae, genus Melanocephalus. Due to its fast growth rate, delicious meat and high market value, it has become one of the important commercial aquaculture species in my country. However, as a typical carnivorous fish, largemouth bass has poor ability to utilize starch in compound feed, which can easily cause glycogen accumulation in liver tissue, sugar and lipid metabolism disorders and metabolic liver disease. Starch, as a bulking agent and adhesive, is crucial in the processing of puffed floating feed. In addition, as feed raw materials such as fish meal and soybean meal become increasingly scarce and their prices continue to rise, it is urgent to find new substitutes for feed raw materials.

[0003] Silkworm excrement, also known as raw silkworm excrement, Ma Minggan, etc., is a by-product of the mulberry silkworm industry. It is composed of dried feces of silkworm larvae, mulberry leaf residues and silkworm bedding. It is rich in crude protein, flavonoids, methionine, vitamins, nitrogen, phosphorus and potassium. It not only has the effects of lowering blood sugar, lowering blood lipids, and anti-inflammatory and antibacterial, but is also a theoretical new non-grain feed raw material and is often used as aquatic feed. In recent years, the artificial feed breeding technology of silkworms has gradually matured and has begun to be demonstrated and promoted. Artificial feed breeding is based on the nutritional needs and feeding characteristics of silkworms. Appropriate raw materials (mulberry leaf powder, soybean meal powder, corn powder, etc.) are used to prepare feed in a suitable ratio to replace the feeding method of mulberry leaf-fed silkworms. Compared with the traditional pure mulberry leaf-fed silkworm excrement, the feed-fed silkworm excrement has a higher crude protein content and lower crude fat, crude fiber and crude ash content. At the same time, due to the adoption of full-age feed-based silkworm breeding, intelligent and factory-based silkworm breeding has become possible, and the amount of silkworm excrement produced is larger and easier to collect and use. However, there are still some problems in the practical application of feed silkworm feces, such as high levels of anti-nutritional factors such as phytic acid, nitrite, and tannin, which leads to the fact that feed silkworm feces cannot be well applied at present. Summary of the invention

[0004] The purpose of the present invention is to provide a fermented feed for silkworm excrement and a preparation method and application thereof. The fermented feed for silkworm excrement has a lower content of anti-nutritional factors and can be better applied to the breeding of freshwater fish, reduce the feed coefficient, improve the growth performance and immune activity of freshwater fish, and at the same time reduce the blood sugar and blood lipid levels of freshwater fish.

[0005] The invention provides a fermented feed for silkworm excrement, comprising feed for silkworm excrement, soybean meal, wheat bran, fermented bacteria, carbon source and inorganic salt; the mass ratio of the feed for silkworm excrement, soybean meal and wheat bran is (45-50):1:1;

[0006] The fermentation bacteria include lactic acid bacteria, yeast and bacillus, and the concentrations of the lactic acid bacteria, yeast and bacillus are 10 6 ~10 9 CFU / L, the volume ratio of the lactic acid bacteria, yeast and bacillus is (1-3):1:1; the mass of the fermentation bacteria is 2%-10% of the total mass of the feed silkworm litter, soybean meal and wheat bran.

[0007] Preferably, the carbon source includes molasses, and the mass of the carbon source is 2% to 3% of the total mass of the feed silkworm litter, soybean meal and wheat bran;

[0008] The inorganic salts include potassium dihydrogen phosphate and ammonium sulfate, and the masses of the potassium dihydrogen phosphate and ammonium sulfate are 0.2% to 0.5% and 0.5% to 1.0% of the total mass of the feed silkworm litter, soybean meal and wheat bran respectively.

[0009] Preferably, the feed silkworm litter includes 3- to 5-year-old feed silkworm litter.

[0010] The present invention also provides a method for preparing the fermented feed for silkworm excrement according to the above technical solution, comprising the following steps:

[0011] Mixing feed silkworm excrement, soybean meal, wheat bran, carbon source, inorganic salt and fermentation bacteria to obtain a raw material mixture;

[0012] aerobically fermenting the raw material mixture to obtain a fermentation product;

[0013] The fermentation product is dried to obtain the fermented feed silkworm litter.

[0014] Preferably, the aerobic fermentation time is 64 to 72 hours, the temperature is 32 to 33° C., and the humidity is 45% to 50%.

[0015] The present invention also provides the use of the fermented silkworm excrement as feed described in the above technical solution or the fermented silkworm excrement as feed prepared by the preparation method described in the above technical solution in the preparation of aquatic feed.

[0016] Preferably, the aquatic feed includes largemouth bass feed.

[0017] The present invention provides an aquatic feed, comprising aquatic compound feed and fermented feed silkworm excrement, wherein the mass of the fermented feed silkworm excrement is 4% to 10% of the mass of the aquatic feed; the fermented feed silkworm excrement is the fermented feed silkworm excrement described in the above technical scheme or the fermented feed silkworm excrement prepared by the preparation method described in the above technical scheme.

[0018] Preferably, the aquatic feed comprises the following components in percentage by weight: 43% fish meal, 13% chicken meal, 0%-14% soybean meal, 4%-10% fermented silkworm excrement, 4%-11.1% cottonseed protein, 5%-10% cassava flour, 5% high-gluten flour, 2% fish oil, 3% soybean oil, 1.5% monocalcium phosphate, 0.3% phosphate ester, 0.5% mineral premix, 0.1% vitamin premix, 0.5% choline chloride, 0.5% betaine, 0%-5.6% cellulose and 1.5% sodium carboxymethyl cellulose.

[0019] The present invention also provides the use of the fermented silkworm excrement for feed described in the above technical scheme, or the fermented silkworm excrement for feed prepared by the preparation method described in the above technical scheme, or the aquatic feed described in the above technical scheme in one or more of freshwater fish farming, improving the growth performance of freshwater fish, improving the immune activity of freshwater fish, reducing blood sugar of freshwater fish, reducing blood lipids of freshwater fish and reducing feed coefficient.

[0020] Beneficial effects:

[0021] The invention provides a fermented feed for breeding silkworm excrement, comprising feed for breeding silkworm excrement, soybean meal, wheat bran, fermented bacteria, carbon source and inorganic salt; the mass ratio of the silkworm excrement, soybean meal and wheat bran is 45-48:1:1; the fermented bacteria comprises lactic acid bacteria, yeast and bacillus, and the strain concentrations of the lactic acid bacteria, yeast and bacillus are 10 6 ~10 9 CFU / L, the volume ratio of the lactic acid bacteria, yeast and bacillus is (1-3): 1: 1; the mass of the fermented strain is 2% to 10% of the total mass of the feed silkworm excrement, soybean meal and wheat bran. Compared with the raw materials that have not been fermented and the silkworm excrement fermented with fermented mulberry leaves, the fermented feed silkworm excrement prepared by the present invention by fermenting the above raw materials contains less anti-nutritional factors, and the content of nutrients such as crude protein, crude ash, crude fat, and total amino acids is increased, which effectively reduces the feed coefficient and can be better applied to the preparation of aquatic feed and the breeding of freshwater fish. It can effectively improve the growth performance and immune activity of freshwater fish, and at the same time, it can reduce the blood sugar and blood lipid content of freshwater fish. At the same time, when the fermented feed silkworm excrement of the present invention is used to prepare aquatic feed, it can replace part of soybean meal to reduce feed costs. The fermented feed silkworm excrement of the present invention not only expands the industrial chain of the sericulture industry, but also has good application potential in healthy breeding. DETAILED DESCRIPTION

[0022] The invention provides a fermented feed for silkworm excrement, comprising feed for silkworm excrement, soybean meal, wheat bran, fermented bacteria, carbon source and inorganic salt; the mass ratio of the feed for silkworm excrement, soybean meal and wheat bran is (45-50):1:1;

[0023] The fermentation bacteria include lactic acid bacteria, yeast and bacillus, and the concentrations of the lactic acid bacteria, yeast and bacillus are 10 6 ~10 9 CFU / L, the volume ratio of the lactic acid bacteria, yeast and bacillus is (1-3):1:1; the mass of the fermentation bacteria is 2%-10% of the total mass of the feed silkworm litter, soybean meal and wheat bran.

[0024] The mass ratio of the feed silkworm excrement, soybean meal and wheat bran of the present invention can be (45-48):1:1; as an embodiment, the mass ratio of the feed silkworm excrement, soybean meal and wheat bran is 48:1:1. As an embodiment, the feed silkworm excrement can be 3-5-year-old feed silkworm excrement; as another embodiment, the feed silkworm excrement can be 5-year-old feed silkworm excrement; the 5-year-old feed silkworm excrement is easy to collect and clean, and has high nutritional value and medicinal value. The reason why the present invention selects feed silkworm excrement, soybean meal and wheat bran as the raw materials for preparing fermented feed silkworm excrement is to increase the fragrance and optimize the fermentation environment of the strain.

[0025] As an embodiment, the lactic acid bacteria may be Lactobacillus plantarum; as another embodiment, the Lactobacillus plantarum may be Lactobacillus plantarum GIM1.140. As an embodiment, the Bacillus may be Bacillus subtilis; as another embodiment, the Bacillus may be Bacillus SEM-2, the deposit number of the Bacillus SEM-2 is GDMCC No.60039, and the Bacillus SEM-2 is disclosed in Chinese patent CN110257309A. As an embodiment, the yeast may be Saccharomyces cerevisiae; as another embodiment, the Saccharomyces cerevisiae may be Saccharomyces cerevisiae GIM2.132. As an embodiment, the strain concentrations of the lactic acid bacteria, yeast and Bacillus are 10 8 ~10 9 CFU / L. The volume ratio of the lactic acid bacteria, yeast and bacillus of the present invention is (1-3):1:1; as an embodiment, the volume ratio of the lactic acid bacteria, yeast and bacillus is 2:1:1. As an embodiment, the mass of the fermented bacteria is 4% to 8% of the total mass of the feed silkworm feces, soybean meal and wheat bran. As an embodiment, the lactic acid bacteria, yeast and bacillus are used in the form of bacterial liquid; the preparation method of the bacterial liquid is not particularly limited, and the conventional preparation method of the bacterial liquid can be used to achieve the corresponding bacterial concentration.

[0026] As an embodiment, the carbon source of the present invention may be molasses. As an embodiment, the mass of the carbon source is 2% to 3% of the total mass of the silkworm excrement, soybean meal and wheat bran; as another embodiment, the mass of the carbon source is 2% of the total mass of the silkworm excrement, soybean meal and wheat bran. As an embodiment, the inorganic salt may be potassium dihydrogen phosphate and ammonium sulfate. As an embodiment, the mass of potassium dihydrogen phosphate and ammonium sulfate is 0.2% to 0.5% and 0.5% to 1.0% of the total mass of the silkworm excrement, soybean meal and wheat bran, respectively; as another embodiment, the mass of potassium dihydrogen phosphate and ammonium sulfate is 0.2% and 0.5% of the total mass of the silkworm excrement, soybean meal and wheat bran, respectively. The carbon source and inorganic salt of the present invention are used for bacterial fermentation to improve nutrition.

[0027] The present invention also provides a method for preparing the fermented feed for silkworm excrement according to the above technical solution, comprising the following steps:

[0028] Mixing feed silkworm excrement, soybean meal, wheat bran, carbon source, inorganic salt and fermentation bacteria to obtain a raw material mixture;

[0029] aerobically fermenting the raw material mixture to obtain a fermentation product;

[0030] The fermentation product is dried to obtain the fermented feed silkworm litter.

[0031] The present invention mixes feed silkworm excrement, soybean meal, wheat bran, carbon source, inorganic salt and fermentation bacteria to obtain a raw material mixture. The present invention has no special limitation on the mixing method, and the conventional mixing method in the art can be used for uniform mixing.

[0032] After obtaining the raw material mixture, as one embodiment, the present invention adjusts the humidity of the raw material mixture to 45% to 50%; as another embodiment, the humidity of the raw material mixture is adjusted to 45%.

[0033] After adjusting the humidity of the raw material mixture, the present invention performs aerobic fermentation on the raw material mixture after adjusting the humidity to obtain a fermentation product. As an embodiment, the aerobic fermentation of the present invention can be solid-state fermentation; as another embodiment, the solid-state fermentation can be static aerobic fermentation. As an embodiment, the aerobic fermentation time is 64 to 72 hours; as another embodiment, the aerobic fermentation time is 64 to 68 hours. As an embodiment, the temperature of the aerobic fermentation is 32 to 33°C.

[0034] After obtaining the fermentation product, the present invention dries the fermentation product to obtain the fermented feed silkworm excrement. As an embodiment, the drying method is drying; as another embodiment, the drying temperature can be 60-70°C; as another embodiment, the drying temperature can be 65°C. As an embodiment, the moisture content of the fermented feed silkworm excrement after drying is less than 10%; the fermented feed silkworm excrement with the moisture content has the advantages of long storage period and high stability.

[0035] As an embodiment, the present invention further comprises crushing and sieving the fermented feed silkworm excrement. The present invention does not specifically limit the crushing method, and the conventional crushing method in the art can be used. As an embodiment, the mesh number of the sieve can be 60 mesh, that is, the particle size of the fermented feed silkworm excrement after sieving is less than or equal to 60 mesh.

[0036] The present invention also provides the use of the fermented silkworm excrement for feeding described in the above technical solution or the fermented silkworm excrement for feeding described in the above technical solution in preparing aquatic feed. As an embodiment, the aquatic feed can be freshwater fish feed; as another embodiment, the freshwater fish feed can be largemouth bass feed.

[0037] The present invention also provides an aquatic feed, including aquatic compound feed and fermented feed silkworm excrement, the mass of the fermented feed silkworm excrement is 4% to 10% of the mass of the aquatic feed; the fermented feed silkworm excrement is the fermented feed silkworm excrement described in the above technical solution or the fermented feed silkworm excrement prepared by the preparation method described in the above technical solution. As an embodiment, the mass of the fermented feed silkworm excrement is 4% to 8% of the mass of the aquatic feed; as another embodiment, the mass of the fermented feed silkworm excrement is 4% to 6% of the mass of the aquatic feed. As an embodiment, the aquatic compound feed of the present invention can be determined according to the nutritional requirements of different fish species. For example, when the aquatic feed is largemouth bass feed, as an embodiment, the aquatic feed includes the following components in percentage by weight: 43% fish meal, 13% chicken meal, 0% to 14% soybean meal, 4% to 10% fermented feed silkworm feces, 4% to 11.1% cottonseed protein, 5% to 10% cassava flour, 5% high-gluten flour, 2% fish oil, 3% soybean oil, 1.5% monocalcium phosphate, 0.3% phosphate ester, 0.5% mineral premix, 0.1% vitamin premix, 0.5% choline chloride, 0.5% betaine, 0.5% cellulose 0% to 5.6% of vitamin C and 1.5% of sodium carboxymethyl cellulose; as another embodiment, the aquatic feed is composed of the following components by mass percentage: 43% of fish meal, 13% of chicken meal, 11.1% of cottonseed protein, 10% of cassava flour, 8% of fermented feed silkworm feces, 5% of high-gluten flour, 2% of fish oil, 3% of soybean oil, 1.5% of monocalcium phosphate, 0.3% of phosphate ester, 0.5% of mineral premix, 0.1% of vitamin premix, 0.5% of choline chloride, 0.5% of betaine and 1.5% of sodium carboxymethyl cellulose. As an embodiment, the phosphate ester can be vitamin C (VC) phosphate. The present invention does not specifically limit the sources of the mineral premix and the vitamin premix, and conventional commercial products in the art can be used. For example, the mineral premix and the vitamin premix in the embodiment of the present invention are purchased from Guangzhou Feixi Te Biotechnology Co., Ltd.

[0038] The present invention also provides the use of the fermented silkworm excrement for breeding according to the technical solution or the fermented silkworm excrement for breeding obtained by the preparation method according to the technical solution or the aquatic feed according to the technical solution in one or more of freshwater fish breeding, improving the growth performance of freshwater fish, improving the immune activity of freshwater fish, reducing blood sugar of freshwater fish, reducing blood lipid of freshwater fish and reducing feed coefficient. As an embodiment, the freshwater fish can be one or more of largemouth black bass, grass carp, mandarin fish and grouper; as another embodiment, the freshwater fish can be largemouth black bass, grass carp, mandarin fish or grouper. As an embodiment, the growth performance can be weight gain rate and / or survival rate; the immune activity can be one or more of lysozyme, alkaline phosphatase and immunoglobulin; the blood lipid can be triglyceride.

[0039] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0040] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art may be used.

[0041] Example 1

[0042] A method for preparing fermented feed for silkworm excrement, comprising the following steps:

[0043] 1. The mass percentage composition of the fermentation base is as follows: 96.00% of 5-year-old feed silkworm feces, 2.00% of soybean meal, and 2.00% of wheat bran.

[0044] The added amounts of molasses, ammonium sulfate, potassium dihydrogen phosphate and microbial fermentation strains are 2.00%, 0.50%, 0.20% and 4.00% of the total mass of the fermentation base material, respectively.

[0045] The microbial strains were a mixed culture of Lactobacillus plantarum, Saccharomyces cerevisiae and Bacillus subtilis. The concentration of each strain before mixing was 10 8 CFU / mL, the volume ratio of bacterial solution is: Saccharomyces cerevisiae: Lactobacillus plantarum: Bacillus subtilis = 1:2:1;

[0046] Lactobacillus plantarum was purchased from Guangdong Microorganism Collection Center with the number GIM1.140; Saccharomyces cerevisiae was purchased from Guangdong Microorganism Collection Center with the number GIM2.132; Bacillus subtilis was Bacillus SEM-2, which was deposited in Guangdong Microorganism Collection Center with the deposit number GDMCC No.60039 and disclosed in Chinese patent CN110257309A.

[0047] 2. Preparation method: Mix the raw materials in step 1 according to the mass percentage, add water to adjust the humidity to 45%, stir evenly, and perform static aerobic fermentation for 64 hours at a fermentation temperature of 32-33° C. to obtain a fermentation product; dry the fermentation product at 65° C. until the moisture content of the fermented feed for silkworm excrement is less than 10%, crush it through a 60-mesh sieve, take the sieve-through, and obtain the fermented feed for silkworm excrement.

[0048] Comparative Example 1

[0049] A method for preparing fermented mulberry leaf silkworm excrement, comprising the following steps:

[0050] The fermented mulberry leaf silkworm litter was prepared by the preparation method in Example 1, the only difference being that the 5-year-old feed silkworm litter in step 1 was replaced with mulberry leaf silkworm litter.

[0051] Comparative Example 2

[0052] Effects of different inoculation levels of microbial fermentation strains on the nutritional components of silkworm excrement

[0053] Comparative Example 2-1

[0054] A method for preparing fermented feed for silkworm excrement, comprising the following steps:

[0055] The fermented feed for silkworm litter was prepared by the preparation method in Example 1, the only difference being that the inoculation amount of the microbial fermentation strain in step 1 was adjusted to 2.00% of the total amount of the fermentation base.

[0056] Comparative Example 2-2

[0057] A method for preparing fermented feed for silkworm excrement, comprising the following steps:

[0058] The fermented feed for silkworm litter was prepared by the preparation method in Example 1, the only difference being that the inoculation amount of the microbial fermentation strain in step 1 was adjusted to 6.00% of the total amount of the fermentation base.

[0059] Comparative Examples 2-3

[0060] A method for preparing fermented feed for silkworm excrement, comprising the following steps:

[0061] The fermented feed for silkworm litter was prepared by the preparation method in Example 1, the only difference being that the inoculation amount of the microbial fermentation strain in step 1 was adjusted to 8.00% of the total amount of the fermentation base material.

[0062] Comparative Examples 2-4

[0063] A method for preparing fermented feed for silkworm excrement, comprising the following steps:

[0064] The fermented feed for silkworm litter was prepared by the preparation method in Example 1, the only difference being that the inoculation amount of the microbial fermentation strain in step 1 was adjusted to 10.00% of the total amount of the fermentation base.

[0065] The effects of different inoculation levels (4.00%, 2.00%, 6.00%, 8.00% and 10.00%) of fermentation bacteria on the nutritional components of fermented feed for silkworm excrement in the preparation process of fermented feed for silkworm excrement in Example 1 and Comparative Examples 2-1 to Comparative Examples 2 to 4.

[0066] The crude protein content was determined by Kjeldahl nitrogen determination according to GB / T 6432-2018; the crude fat content was determined by Soxhlet extraction according to GB / T 6433-2006; the crude ash content was determined by 550℃ high temperature ashing method according to GB / T 6438-2007; the nitrite content was determined by colorimetry according to GB / T 13085-2018; and the phytic acid content was determined by ferric chloride colorimetry. The results are shown in Tables 1 and 2.

[0067] Table 1 Effects of different inoculation levels of fermented bacteria on the nutritional components of silkworm excrement

[0068] serial number Group Crude protein % Crude fat % Crude ash % Comparative Example 2-1 2.00％ <![CDATA[20.15±1.04 a ]]> <![CDATA[1.79±0.12 a ]]> <![CDATA[12.26±0.44 a ]]> Example 1 4.00％ <![CDATA[20.57±1.25 a ]]> <![CDATA[1.73±0.17 a ]]> <![CDATA[11.84±0.24 a ]]> Comparative Example 2-2 6.00％ <![CDATA[20.34±1.19 a ]]> <![CDATA[1.70±0.26 a ]]> <![CDATA[11.68±0.50 a ]]> Comparative Examples 2-3 8.00％ <![CDATA[20.28±1.33 a ]]> <![CDATA[1.75±0.25 a ]]> <![CDATA[12.12±0.38 a ]]> Comparative Examples 2-4 10.00％ <![CDATA[20.42±1.24 a ]]> <![CDATA[1.77±0.19 a ]]> <![CDATA[11.49±0.58 a ]]>

[0069] Table 2 Effects of different inoculation levels of fermented bacteria on the anti-nutritional components of silkworm litter in feed

[0070] serial number Group Nitrite mg / kg Phytic acid mg / g Comparative Example 2-1 2.00％ <![CDATA[1.16±0.08 d ]]> <![CDATA[3.92±0.17 a ]]> Example 1 4.00％ <![CDATA[0.99±0.10 c ]]> <![CDATA[3.83±0.13 a ]]> Comparative Example 2-2 6.00％ <![CDATA[0.71±0.12 b ]]> <![CDATA[3.73±0.15 a ]]> Comparative Examples 2-3 8.00％ <![CDATA[0.58±0.06 b ]]> <![CDATA[3.76±0.09 a ]]> Comparative Examples 2-4 10.00％ <![CDATA[0.13±0.04 a ]]> <![CDATA[3.64±0.21 a ]]>

[0071] Note: The lowercase letters a, b, and c in Tables 1 and 2 represent the significant differences among the three groups of data at the 0.05 level. The same lowercase letters mean no significant differences, while different lowercase letters mean significant differences. The same below.

[0072] From Table 1 and Table 2, it can be concluded that the crude protein content of the fermented silkworm excrement shows a trend of first increasing and then decreasing with the increase of the inoculation amount; the crude fat content fluctuates very little with the increase of the inoculation amount; the crude ash content shows a trend of first decreasing, then increasing, and then decreasing with the increase of the inoculation amount. The nitrite content of the fermented silkworm excrement significantly decreases with the increase of the inoculation amount; the phytic acid content shows a decreasing trend with the increase of the inoculation amount. Taking the crude protein content as the evaluation index, the appropriate inoculation amount of the mixed strain is 4.00%.

[0073] Test Example 1

[0074] Differences in nutritional components between fermented silkworm excrement in Example 1 and fermented silkworm excrement in mulberry leaves in Comparative Example 1

[0075] The nutritional components of the fermented silkworm excrement prepared in Example 1 and the fermented silkworm excrement prepared in Comparative Example 1 were compared. The crude protein, crude fat and crude ash were determined by the same method as in Comparative Example 2. The results are shown in Table 3.

[0076] Table 3 Comparison of nutritional components between fermented feed silkworm excrement and fermented mulberry leaf silkworm excrement

[0077] Group Crude protein % Crude fat % Crude ash % Fermented feed for silkworm breeding <![CDATA[19.22±0.40 b ]]> <![CDATA[1.90±0.22 b ]]> <![CDATA[11.06±0.15 a ]]> Fermented mulberry leaf silkworm excrement <![CDATA[14.43±1.24 a ]]> <![CDATA[1.26±0.17 a ]]> <![CDATA[13.22±0.61 b ]]>

[0078] It can be concluded from Table 3 that the crude protein and crude fat contents of the fermented silkworm litter prepared in Example 1 are significantly higher than those of the fermented mulberry leaf silkworm litter prepared in Comparative Example 1, and the crude ash content is significantly lower than that of the fermented mulberry leaf silkworm litter, indicating that the nutritional value of fermented silkworm litter in feed is better than that of fermented mulberry leaf silkworm litter.

[0079] Test Example 2

[0080] Differences in nutritional components of silkworm excrement before and after fermentation

[0081] The fermented silkworm excrement prepared in Example 1 was compared with the silkworm excrement without fermentation strains (the mass percentage of silkworm excrement before fermentation was: 96% of silkworm excrement at the age of 5, 2% of soybean meal and 2% of wheat bran) for nutritional components. The crude protein, crude fat, crude ash, nitrite and phytic acid contents were determined by referring to the method in Comparative Example 2; the amino acid content was determined by acid hydrolysis method according to standard GB / T 18246-2019; the tannin content was determined by spectrophotometry according to GB / T 27985-2011; the crude fiber content was determined by filter crucible method according to standard GB / T 6434-2022. The results are shown in Tables 4 and 5.

[0082] Table 4 Comparison of nutritional components of silkworm excrement before and after fermentation

[0083]

[0084] Table 5 Comparison of anti-nutritional components in feed silkworm litter before and after fermentation

[0085] Group Phytic acid (mg / g) Nitrite (mg / kg) Tannin(g / kg) Crude fiber % Before fermentation <![CDATA[3.77±0.18 a ]]> <![CDATA[7.22±0.08 b ]]> <![CDATA[20.28±0.34 b ]]> <![CDATA[10.96±0.45 b ]]> After fermentation <![CDATA[3.30±0.26 a ]]> <![CDATA[0.91±0.11 a ]]> <![CDATA[18.21±0.47 a ]]> <![CDATA[9.12±0.27 a ]]>

[0086] It can be concluded from Tables 4 and 5 that compared with before fermentation, the crude protein, crude ash, crude fat and total amino acid contents of the fermented silkworm feces increased, among which the crude ash and total amino acid contents increased significantly; the phytic acid, tannin, nitrite and crude fiber contents decreased, among which the nitrite, tannin and crude fiber contents decreased significantly.

[0087] Example 2

[0088] Application of feed supplemented with fermented feed containing silkworm excrement in the culture of largemouth bass

[0089] 270 largemouth bass with an initial body weight of about 7g were selected and randomly divided into 3 groups, with 3 replicates in each group and 30 fish in each replicate. The fermented feed silkworm excrement prepared in Example 1 was added to the largemouth bass compound feed (12% starch) at a ratio of 8% by mass to prepare the experimental group feed, and the normal starch level group feed (8% starch, control group A) and the largemouth bass compound feed (12% starch, control group B) with high starch levels were used as controls, and a 56-day breeding experiment was carried out. The composition of the feed in the experimental group, control group A and control group B is shown in Table 6.

[0090] After the experiment, all the fish in each replicate were counted and weighed, and the weight gain rate and feed coefficient were calculated. Five fish were randomly selected from each replicate, weighed, and the fatness was calculated. Then blood was collected from the tail vein, left to stand at 4°C for 2 hours, centrifuged at 3500r / min for 10 minutes, and separated to prepare serum. The fish after blood collection were dissected and separated, and the liver-to-body ratio and abdominal fat rate were calculated.

[0091] Table 6 Experimental feed composition (dry matter, %)

[0092]

[0093]

[0094] Note: Vitamin premixes and mineral premixes were purchased from Guangzhou Feixi Te Biotechnology Co., Ltd.

[0095] The relevant kits of Nanjing Jiancheng Bioengineering Institute were used to detect serum biochemical and immunological indicators, including blood glucose (GLU), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C); lysozyme (LZM), alkaline phosphatase (AKP), immunoglobulin M (IgM), complement C3 and complement C4, etc. The results are shown in Tables 7 to 9.

[0096] Table 7 Analysis of growth performance indicators of largemouth bass fed with different feeds

[0097] Group Weight gain% <![CDATA[Condition factor (g / cm 3 )]]> Feed Coefficient Liver to body ratio% Abdominal fat percentage Control group A <![CDATA[847.94±37.33 a ]]> <![CDATA[2.07±0.03 a ]]> <![CDATA[1.09±0.02 b ]]> <![CDATA[1.35±0.12 a ]]> <![CDATA[1.72±0.20 a ]]> Control group B <![CDATA[892.44±32.40 ab ]]> <![CDATA[2.11±0.05 ab ]]> <![CDATA[1.06±0.02 b ]]> <![CDATA[2.13±0.81 b ]]> <![CDATA[1.78±0.12 a ]]> Experimental Group <![CDATA[920.25±15.57 b ]]> <![CDATA[2.16±0.01 b ]]> <![CDATA[1.01±0.02 a ]]> <![CDATA[1.27±0.08 a ]]> <![CDATA[1.74±0.18 a ]]>

[0098] Table 8 Analysis of serum biochemical indexes after feeding largemouth bass with different feeds

[0099] Group GLU (mmol / L) TG (mmol / L) LDL-C (mmol / L) HDL-C (mmol / L) Control group A <![CDATA[8.44±0.28 a ]]> <![CDATA[4.07±0.21 a ]]> <![CDATA[3.01±0.35 a ]]> <![CDATA[2.81±0.19 a ]]> Control group B <![CDATA[10.52±0.35 b ]]> <![CDATA[5.21±0.47 b ]]> <![CDATA[3.88±0.17 b ]]> <![CDATA[2.78±0.34 a ]]> Experimental Group <![CDATA[7.97±0.39 a ]]> <![CDATA[4.41±0.34 a ]]> <![CDATA[3.04±0.12 a ]]> <![CDATA[3.13±0.21 a ]]>

[0100] Table 9 Analysis of serum immune indexes of largemouth bass fed with different feeds

[0101] Group LZM (U / mL) AKP (U / mL) IgM(g / L) Complement C3 (mg / L) Complement C4 (mg / L) Control group A <![CDATA[387.38±36.62 b ]]> <![CDATA[8.89±0.17 a ]]> <![CDATA[1.83±0.21 b ]]> <![CDATA[289.78±12.83 ab ]]> <![CDATA[275.27±25.68 a ]]> Control group B <![CDATA[302.84±28.27 a ]]> <![CDATA[9.02±0.21 a ]]> <![CDATA[1.58±0.09 a ]]> <![CDATA[252.17±27.94 a ]]> <![CDATA[260.17±13.64 a ]]> Experimental Group <![CDATA[398.42±19.65 b ]]> <![CDATA[8.81±0.34 a ]]> <![CDATA[1.87±0.16 b ]]> <![CDATA[292.05±15.29 b ]]> <![CDATA[268.09±36.04 a ]]>

[0102] It can be concluded from Tables 7 to 9 that compared with control group A and control group B, the growth performance indicators of largemouth bass in the experimental group (8% fermented feed silkworm litter was added to the feed) had lower feed coefficient and organ-body ratio, and higher weight gain rate and fatness; compared with control group B (high-level starch group), the serum GLU, TG and LDL-C levels of the experimental group were significantly reduced, and the immunological indicators LZM, IgM and complement C3 activity were significantly improved. These data show that adding the fermented feed silkworm litter of the present invention to the high-starch level sea bass feed can effectively improve the growth performance of sea bass, reduce feed coefficient, blood sugar and blood lipids, and improve the immune activity of the body.

[0103] It can be concluded from the above embodiments that the fermented feed for silkworm excrement of the present invention has a lower content of anti-nutritional factors, can be better applied to the breeding of freshwater fish, reduce the feed coefficient, can improve the growth performance and immune activity of freshwater fish, and can also reduce the blood sugar and blood lipid content of freshwater fish.

[0104] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A fermented feed for silkworm litter, characterized in that: The feed comprises silkworm excrement, soybean meal, wheat bran, fermentation bacteria, carbon source and inorganic salt; the mass ratio of the silkworm excrement, soybean meal and wheat bran is (45-50):1:1; The fermentation bacteria include lactic acid bacteria, yeast and bacillus, and the concentrations of the lactic acid bacteria, yeast and bacillus are 10 6 ~10 9 CFU / L, the volume ratio of the lactic acid bacteria, yeast and bacillus is (1-3):1:1; the mass of the fermentation bacteria is 2%-10% of the total mass of the feed silkworm litter, soybean meal and wheat bran.

2. The fermented feed for silkworm litter according to claim 1, characterized in that: The carbon source includes molasses, and the mass of the carbon source is 2% to 3% of the total mass of the feed silkworm litter, soybean meal and wheat bran; The inorganic salts include potassium dihydrogen phosphate and ammonium sulfate, and the masses of the potassium dihydrogen phosphate and ammonium sulfate are 0.2% to 0.5% and 0.5% to 1.0% of the total mass of the feed silkworm litter, soybean meal and wheat bran respectively.

3. The fermented feed for silkworm litter according to claim 1, characterized in that: The feed silkworm litter includes 3- to 5-year-old feed silkworm litter.

4. The method for preparing fermented feed for silkworm excrement according to any one of claims 1 to 3, characterized in that: The steps include: Mixing feed silkworm excrement, soybean meal, wheat bran, carbon source, inorganic salt and fermentation bacteria to obtain a raw material mixture; aerobically fermenting the raw material mixture to obtain a fermentation product; The fermentation product is dried to obtain the fermented feed silkworm litter.

5. The preparation method according to claim 4, characterized in that: The aerobic fermentation lasts for 64 to 72 hours, the temperature is 32 to 33° C., and the humidity is 45% to 50%.

6. Use of the fermented silkworm excrement as claimed in any one of claims 1 to 3 or the fermented silkworm excrement as prepared by the preparation method according to claim 4 or 5 in preparing aquatic feed.

7. The use according to claim 6, characterized in that: The aquatic feed includes largemouth bass feed.

8. An aquatic feed, characterized in that: It comprises aquatic compound feed and fermented silkworm excrement, wherein the mass of the fermented silkworm excrement is 4% to 10% of the mass of the aquatic feed; the fermented silkworm excrement is the fermented silkworm excrement according to any one of claims 1 to 3 or the fermented silkworm excrement prepared by the preparation method according to claim 4 or 5.

9. The aquatic feed according to claim 8, characterized in that: The aquatic feed comprises the following components in percentage by weight: 43% of fish meal, 13% of chicken meal, 0%-14% of soybean meal, 4%-10% of fermented silkworm excrement, 4%-11.1% of cottonseed protein, 5%-10% of cassava flour, 5% of high-gluten flour, 2% of fish oil, 3% of soybean oil, 1.5% of monocalcium phosphate, 0.3% of phosphate ester, 0.5% of mineral premix, 0.1% of vitamin premix, 0.5% of choline chloride, 0.5% of betaine, 0%-5.6% of cellulose and 1.5% of sodium carboxymethyl cellulose.

10. Use of the fermented silkworm excrement as claimed in any one of claims 1 to 3, or the fermented silkworm excrement as claimed in claim 4 or 5, or the aquatic feed as claimed in claim 8 or 9 in one or more of freshwater fish farming, improving the growth performance of freshwater fish, improving the immune activity of freshwater fish, reducing blood sugar in freshwater fish, reducing blood lipids in freshwater fish, and reducing feed coefficient.

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