Granulated feed for laboratory mice and preparation method thereof

Abstract

The invention discloses a pellet feed for laboratory mice and a preparation method of the pellet feed. The feed consists of the following raw materials in percentage by weight: 42-50% of corn, 8-12% of fermented soybean meal, 4-8% of insect protein (hermetia illucens larva powder), 2-4% of maltodextrin, 1-2% of inulin, 0.5-2% of inactivated enterococcus faecalis, 1.5-3% of a vitamin premix, 3-5% of a mineral premix, 0.3-0.8% of xylooligosaccharide, 2-4% of vegetable oil, 1-3% of cellulose and the balance of auxiliary materials. The method has the advantages that heavy metal and micro-plastic pollution are avoided, allergens are removed, and the survival rate of laboratory mice is increased by 20%; active ingredients of the inactivated enterococcus faecalis are reserved through a spraying process, and the number of beneficial bacteria in the intestinal tract is increased by 25-35% compared with a contrast; the feed conversion rate is increased by 21-32%, the weight gain is stable, and the fluctuation of experimental data is reduced.

Description

Technical Field

[0001] This invention relates to the field of laboratory mouse feed technology, and in particular to a pelleted feed for laboratory mice and its preparation method. Background Technology

[0002] As an important model organism in life science research, the stability of the physiological state of laboratory mice directly affects the reliability and reproducibility of experimental results. Feed, as the core carrier of nutrition for laboratory mice, plays a decisive role in their growth and development, immune function, and the quality of model construction. In particular, immunodeficient mice (such as NOD / SCID, BALB / c-nu, etc.) are more sensitive to nutrients, contaminants, and bioactive substances in their feed due to their impaired immune system function. Their feed must simultaneously meet the requirements of nutritional balance, safety, and functional regulation.

[0003] The following key problems exist in existing laboratory mouse feed:

[0004] The reliance on imported fishmeal for protein sources raises concerns about safety and sustainability: Traditional formulations often use Peruvian fishmeal as a high-quality protein source, but its supply chain is susceptible to fluctuations in marine resources and international trade policies, resulting in poor price stability. Furthermore, pollutants such as heavy metals (e.g., mercury, lead) and microplastics from the marine environment tend to accumulate in fishmeal, increasing health risks in immunodeficient mice. Simultaneously, overfishing has led to the depletion of Peruvian anchovy resources, which contradicts the trend towards green laboratory animal feed.

[0005] Poor stability and low bioavailability of functional components: Some feeds are fortified with probiotics (such as Enterococcus faecalis) to improve gut health, but these are often granulated at high temperatures (110-140℃) together with the feed mix, which destroys the active components of the probiotics (such as cell wall structure and metabolites), reducing their regulatory effect on the gut microbiota. In addition, existing carriers (such as shrimp head powder) contain indigestible components (chitin) and potential allergens, which may cause intestinal irritation or reduced feed intake in immunodeficient mice.

[0006] Inadequate nutritional suitability and large fluctuations in experimental data: Immunodeficient mice have a high demand for specific amino acids (such as arginine and glutamine) and prebiotics, but existing feeds mostly follow the formulas of ordinary laboratory mice and have not been optimized for their fragile intestinal barrier and poor nutrient absorption capacity, which can easily lead to slow weight gain, increased risk of infection, and affect the stability of experimental models.

[0007] To address the aforementioned issues, developing a pelleted feed for laboratory mice with sustainable raw materials, stable functional components, and precisely tailored nutrition is of great significance for improving the quality of immunodeficient mouse models and advancing biomedical research. This invention, based on the shortcomings of existing technologies, aims to provide a safe, efficient, and environmentally friendly feed solution for laboratory mice by innovating protein sources, optimizing the functional component addition process, and precisely formulating nutritional ratios. Summary of the Invention

[0008] The main technical problem solved by this invention is to provide a pellet feed for laboratory mice and a method for preparing the same, thereby solving one or more of the problems in the prior art.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a pelleted feed for laboratory mice, the innovation of which lies in that it is composed of the following raw materials by weight percentage:

[0010] Corn 42-50%, fermented soybean meal 8-12%, insect protein (black soldier fly larvae powder) 4-8%, maltodextrin 2-4%, inulin 1-2%, inactivated Enterococcus faecalis 0.5-2%, vitamin premix 1.5-3%, mineral premix 3-5%, xylooligosaccharide 0.3-0.8%, vegetable oil 2-4%, cellulose 1-3%, with the remainder being auxiliary materials.

[0011] In some embodiments, the insect protein is replaced with a compound of fermented soybean meal and Cordyceps militaris powder, wherein the fermented soybean meal accounts for 60-70% and the Cordyceps militaris powder accounts for 30-40%.

[0012] In some embodiments, the method for preparing inactivated Enterococcus faecalis is as follows: after culturing Enterococcus faecalis at 37°C for 24 hours, it is inactivated by 0.5% formaldehyde solution for 30 minutes, the bacterial cells are collected by centrifugation, and then freeze-dried (at -40°C and a vacuum of 10 Pa) and pulverized to 200 mesh.

[0013] In some embodiments, the vitamin premix contains 5000-8000 IU / kg of vitamin A, 1000-2000 IU / kg of vitamin D3, 50-80 mg / kg of vitamin E, and 2-5 mg / kg of vitamin K3.

[0014] In some embodiments, the mineral premix contains 80-120 mg / kg of iron, 60-100 mg / kg of zinc, 0.3-0.5 mg / kg of selenium, and 30-50 mg / kg of manganese.

[0015] In some embodiments, the excipients are 1-2% calcium gluconate and 0.5-1% L-glutamine.

[0016] A method for preparing pelleted feed for laboratory mice includes the following steps:

[0017] (1) Raw material pretreatment: Corn and fermented soybean meal are crushed to 80-100 mesh, and insect protein is ultra-finely crushed to 120 mesh;

[0018] (2) Mixing: Mix the pulverized material from step (1) with vitamin premix, mineral premix, xylooligosaccharide, vegetable oil, cellulose and excipients, and stir for 15-20 minutes until uniform;

[0019] (3) Granulation: After the mixture is treated by a conditioner (steam temperature 90-100℃), it is granulated by a ring die pellet mill (die diameter 4-6mm) and cooled to room temperature;

[0020] (4) Functional component spraying: Inactivated Enterococcus faecalis is mixed with maltodextrin and inulin to form a suspension. When the pelleted feed after step (3) is cooled to below 60°C, it is uniformly sprayed onto the surface of the pellets using a fluidized bed spraying process. The amount of spraying is 1-3% of the total weight of the feed.

[0021] (5) Drying and packaging: Dry the coated pelleted feed at 45-55℃ until the moisture content is ≤10%, and then seal and package it.

[0022] In some embodiments, the solid-liquid ratio of the suspension in step (4) is 1:3-5 (g / mL), and the solvent is sterile deionized water.

[0023] In some embodiments, the inlet air temperature of the fluidized bed spraying in step (4) is 40-50°C and the atomization pressure is 0.2-0.3 MPa.

[0024] In some embodiments, the granules after granulation in step (3) have a diameter of 5-8 mm and a length of 10-15 mm.

[0025] The beneficial effects of this invention are:

[0026] Raw material sustainability: It replaces imported fishmeal, reduces supply chain risks, and reduces carbon emissions from insect protein farming by more than 60% compared to fishmeal;

[0027] Improved safety: No heavy metal or microplastic contamination, removal of allergens (such as chitin from shrimp heads), and a 20% increase in the survival rate of laboratory mice (comparative control group).

[0028] High functional efficiency: The inactivated Enterococcus faecalis retains its active ingredients through a spraying process, and the number of beneficial intestinal bacteria is increased by 25-35% compared with the control group;

[0029] Experimental reliability: Feed conversion rate increased by 21-32%, body weight gain was stable, and fluctuations in experimental data were reduced. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0031] Figure 1 This is a flowchart of a method for preparing pelleted feed for laboratory mice according to the present invention. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] Formula (by weight percentage):

[0035] Corn 45%, fermented soybean meal 10%, black soldier fly larvae powder 6%, maltodextrin 3%, inulin 1.5%, inactivated Enterococcus faecalis 1%, vitamin premix 2%, mineral premix 4%, xylooligosaccharide 0.5%, vegetable oil 3%, cellulose 2%, and excipients (calcium gluconate 1.5%, L-glutamine 0.5%).

[0036] Preparation method:

[0037] (1) Grind corn and fermented soybean meal to 90 mesh, and ultrafine grind black soldier fly larvae powder to 120 mesh;

[0038] (2) Mix the pulverized materials with vitamin premix, mineral premix, xylooligosaccharide, vegetable oil, cellulose and excipients, and stir for 18 minutes;

[0039] (3) Conditioning temperature 95℃, granulation diameter 6mm, cooling to room temperature;

[0040] (4) Prepare a suspension by mixing inactivated Enterococcus faecalis with maltodextrin and inulin in a ratio of 1:3:1.5, and spray it in a fluidized bed at a temperature below 60°C (air inlet temperature 45°C, atomization pressure 0.25MPa).

[0041] (5) Dry at 50℃ until the moisture content is 8%, then seal and package.

[0042] Example 2

[0043] Formula (by weight percentage):

[0044] Corn 42%, fermented soybean meal 12%, Cordyceps militaris powder-fermented soybean meal compound (3:7) 8%, maltodextrin 4%, inulin 2%, inactivated Enterococcus faecalis 2%, vitamin premix 3%, mineral premix 5%, xylooligosaccharide 0.8%, vegetable oil 4%, cellulose 3%, and excipients (calcium gluconate 2%, L-glutamine 1%).

[0045] Preparation method:

[0046] Similar to Example 1, only the ratio of the compound protein and the solid-liquid ratio of the spray suspension were adjusted to 1:2:1.

[0047] Example 3

[0048] Formula (by weight percentage):

[0049] Corn 50%, fermented soybean meal 8%, black soldier fly larvae powder 4%, maltodextrin 2%, inulin 1%, inactivated Enterococcus faecalis 0.5%, vitamin premix 1.5%, mineral premix 3%, xylooligosaccharide 0.3%, vegetable oil 2%, cellulose 1%, and excipients (calcium gluconate 1%, L-glutamine 0.5%).

[0050] Preparation method:

[0051] Same as in Example 1, granulation diameter 5mm, spray inlet air temperature 40℃.

[0052] Comparative example (using the original patented formula)

[0053] Formula (by weight percentage):

[0054] The ingredients are: 45% corn, 5% Peruvian fish meal, 10% soybean meal, 3% shrimp head powder, 1% common probiotics (not inactivated), 2% vitamin premix, 4% mineral premix, 3% vegetable oil, 2% cellulose, and the remainder are auxiliary ingredients.

[0055] Preparation method:

[0056] The probiotics and the mixture were granulated together at 130°C (without spraying).

[0057] Comparison of experimental data

[0058] Forty SPF-grade NOD / SCID mice (6-8 weeks old, half male and half female) were randomly divided into four groups (Examples 1-3, Comparative Examples), with 10 mice in each group. After feeding for 4 weeks, the following indicators were measured:

[0059]

[0060] The technical principles of this technical solution are as follows:

[0061] Sustainable protein system: Insect protein (black soldier fly) and fermented soybean meal are combined to provide balanced amino acids (such as lysine content of 5.2-5.8g / 100g) and there is no risk of marine pollutants; Cordycepin in Cordyceps militaris powder can synergistically enhance the antioxidant capacity of immunodeficient mice.

[0062] Functional component stabilization: Maltodextrin-inulin carrier stabilizes the cell wall structure of inactivated Enterococcus faecalis through hydrogen bonds. After granulation, it is sprayed (<60℃) to avoid high temperature damage to peptidoglycan activity, ensuring its adhesion and inhibitory effect on harmful intestinal bacteria (the Salmonella infection rate was 0% in the experiment).

[0063] Intestinal microecological regulation: Inulin and xylooligosaccharides, as prebiotics, can promote the proliferation of lactic acid bacteria (up to 8.5 log CFU / g in Example 2) and improve the intestinal barrier function of immunodeficient mice.

[0064] The advantages of this technical solution are:

[0065] Raw material sustainability: It replaces imported fishmeal, reduces supply chain risks, and reduces carbon emissions from insect protein farming by more than 60% compared to fishmeal;

[0066] Improved safety: No heavy metal or microplastic contamination, removal of allergens (such as chitin from shrimp heads), and a 20% increase in the survival rate of laboratory mice (comparative control group).

[0067] High functional efficiency: The inactivated Enterococcus faecalis retains its active ingredients through a spraying process, and the number of beneficial intestinal bacteria is increased by 25-35% compared with the control group;

[0068] Experimental reliability: Feed conversion rate increased by 21-32%, body weight gain was stable, and fluctuations in experimental data were reduced.

[0069] This invention provides a nutritionally balanced, safe, and controllable feed program for immunodeficient mice through raw material innovation and process optimization, which is suitable for long-term experimental research.

[0070] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A pelleted feed for laboratory mice, characterized in that: It consists of the following raw materials by weight percentage: Corn 42-50%, fermented soybean meal 8-12%, insect protein (black soldier fly larvae powder) 4-8%, maltodextrin 2-4%, inulin 1-2%, inactivated Enterococcus faecalis 0.5-2%, vitamin premix 1.5-3%, mineral premix 3-5%, xylooligosaccharide 0.3-0.8%, vegetable oil 2-4%, cellulose 1-3%, with the remainder being auxiliary materials.

2. The laboratory mouse pellet feed according to claim 1, characterized in that: The insect protein is replaced with a compound of fermented soybean meal and Cordyceps militaris powder, wherein fermented soybean meal accounts for 60-70% and Cordyceps militaris powder accounts for 30-40%.

3. The laboratory mouse pellet feed according to claim 1, characterized in that: The method for preparing the inactivated Enterococcus faecalis is as follows: after culturing Enterococcus faecalis at 37°C for 24 hours, it is inactivated by 0.5% formaldehyde solution for 30 minutes, the bacterial cells are collected by centrifugation, and then freeze-dried (at -40°C and a vacuum of 10 Pa) and pulverized to 200 mesh.

4. The laboratory mouse pellet feed according to claim 1, characterized in that: The vitamin premix contains vitamin A 5000-8000 IU / kg, vitamin D3 1000-2000 IU / kg, vitamin E 50-80 mg / kg, and vitamin K3 2-5 mg / kg.

5. The laboratory mouse pellet feed according to claim 1, characterized in that: The mineral premix contains 80-120 mg / kg of iron, 60-100 mg / kg of zinc, 0.3-0.5 mg / kg of selenium, and 30-50 mg / kg of manganese.

6. The laboratory mouse pellet feed according to claim 1, characterized in that: The excipients are 1-2% calcium gluconate and 0.5-1% L-glutamine.

7. A method for preparing laboratory mouse pellet feed as described in claim 1, characterized in that: Includes the following steps: (1) Raw material pretreatment: Corn and fermented soybean meal are crushed to 80-100 mesh, and insect protein is ultra-finely crushed to 120 mesh; (2) Mixing: Mix the pulverized material from step (1) with vitamin premix, mineral premix, xylooligosaccharide, vegetable oil, cellulose and excipients, and stir for 15-20 minutes until uniform; (3) Granulation: After the mixture is treated by a conditioner (steam temperature 90-100℃), it is granulated by a ring die pellet mill (die diameter 4-6mm) and cooled to room temperature; (4) Functional component spraying: Inactivated Enterococcus faecalis is mixed with maltodextrin and inulin to form a suspension. When the pelleted feed after step (3) is cooled to below 60°C, it is uniformly sprayed onto the surface of the pellets using a fluidized bed spraying process. The amount of spraying is 1-3% of the total weight of the feed. (5) Drying and packaging: Dry the coated pelleted feed at 45-55℃ until the moisture content is ≤10%, and then seal and package it.

8. The method for preparing pelleted feed for laboratory mice according to claim 7, characterized in that: The solid-liquid ratio of the suspension in step (4) is 1:3-5 (g / mL), and the solvent is sterile deionized water.

9. The method for preparing pelleted feed for laboratory mice according to claim 7, characterized in that: In step (4), the inlet air temperature of fluidized bed spraying is 40-50℃ and the atomization pressure is 0.2-0.3MPa.

10. The method for preparing pelleted feed for laboratory mice according to claim 7, characterized in that: In step (3), the granulated particles have a diameter of 5-8 mm and a length of 10-15 mm.

Images