Special compound protein feed for fur animals and its preparation method

Abstract

The present application belongs to the technical field of fur animal feed production, and discloses a special compound protein feed for fur animals and a preparation method thereof. The raw materials of the feed include the following components in parts by weight: 20-30 parts of black soldier fly worm powder, 12-22 parts of yellow mealworm worm powder, 16-26 parts of feather powder, 11-19 parts of blood powder, and 13-23 parts of amino acid residue. The feed is prepared by the method of raw material grading, differential pretreatment, independent temperature control sterilization, multi-stage particle size crushing, segmented enzymatic hydrolysis, and curing, drying and packaging. The preparation of the special compound protein feed for fur animals realizes high sulfur amino acid enrichment, active peptide retention, balanced amino acid ratio, good palatability, and can significantly improve the body weight, feed intake and feed utilization of fur animals during the growing period, and improve the immunity, protein / fat metabolism capacity, fur density, pinna length and skin quality of animals during the winter hair period, shorten the hair replacement cycle, and is suitable for full-process addition for large-scale fur animal breeding.

Description

Technical Field

[0001] This invention belongs to the field of fur animal feed production technology, specifically relating to a special compound protein feed for fur animals (such as mink, fox, raccoon dog, etc.) that integrates insect-derived active protein, animal keratin, hemoglobin, and fermented amino acid by-products, as well as its preparation method and application through gradient enzymatic hydrolysis. Background Technology

[0002] Fur-bearing animals such as foxes, raccoon dogs, and minks are typical economically important animals, and their farming efficiency mainly depends on the survival rate, molting efficiency, and pelt quality. The growth of fur-bearing animals is divided into three key stages: the growth period, the molting period, and the winter down cultivation period. The metabolic and nutritional requirements of each stage differ significantly, and their down growth, pelt development, stress resistance, and intestinal digestive function place stringent demands on the protein ratio and nutritional balance of the feed. Therefore, providing precise nutritional feed throughout the entire process is the core key to ensuring farming efficiency and pelt quality.

[0003] Currently, the industry relies heavily on expensive imported fishmeal, resulting in high farming costs. Meanwhile, most commercially available fur-bearing animal feeds are generic formulas that fail to meet the nutritional needs of fur-bearing animals throughout their entire growth cycle, exhibiting significant technical deficiencies. Firstly, these feeds often have a single protein source, an unbalanced amino acid profile, and low digestibility, failing to meet the protein metabolism requirements at different stages. This easily leads to insufficient feed intake, slow growth, and ineffective nutrient supply to the fur and pelt, resulting in prolonged farming cycles, low farming efficiency, and ultimately, fur loss and reduced density. Secondly, the molting period is a high-stress phase for fur-bearing animals. Existing feeds lack components for intestinal health and stress relief, failing to alleviate metabolic disorders and weakened immunity during molting. Animals are prone to stress-induced hair loss, baldness, and prolonged molting cycles. Simultaneously, intestinal dysfunction and fluctuating feed intake significantly reduce feed utilization. In addition, conventional feeds are mostly customized formulas for a single stage, which cannot be universally applied throughout the growth period, molting period, and winter down cultivation period. Frequent feed changes are required during the breeding process, which is not only cumbersome and increases breeding costs, but also aggravates intestinal stress in animals, causing problems such as hair loss and growth stagnation.

[0004] Therefore, developing a compound protein feed specifically for fur-bearing animals that is suitable for the entire growth cycle and has the functions of intestinal conditioning, stress resistance, promoting molting, improving quality and reducing costs is of great significance for improving the quality of fur and the overall benefits of breeding, and for meeting the needs of large-scale and standardized breeding. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a compound protein feed specifically for fur-bearing animals and its preparation method. By optimizing the compound protein ratio and incorporating intestinal health and stress-relief functional components, this invention can meet the feeding needs of fur-bearing animals during their growth and winter coat stages. The feed prepared by this invention not only achieves enrichment of high-sulfur amino acids, retention of active peptides, and a balanced amino acid ratio, but also improves the intestinal health of fur-bearing animals, increases their average daily feed intake and digestibility, alleviates stress-induced hair loss during molting, and enhances immunity and protein / fat metabolism. Simultaneously, it provides specialized nutrition for the development of down and pelts, effectively increasing down length, guard hair length, and pelt length. The finished feed product exhibits strong stability and excellent palatability, making it suitable for use throughout the entire process of large-scale fur-bearing animal farming.

[0006] The primary objective of this invention is to provide a compound protein feed specifically for fur-bearing animals.

[0007] The second objective of this invention is to provide a method for preparing a compound protein feed specifically for fur-bearing animals.

[0008] A third objective of this invention is to provide the application of the aforementioned compound protein feed specifically for fur-bearing animals.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] In the first aspect, the present invention provides a compound protein feed for fur-bearing animals, the raw materials comprising the following components by weight: 20-30 parts black soldier fly powder, 12-22 parts yellow mealworm powder, 16-26 parts feather meal, 11-19 parts blood meal, and 13-23 parts amino acid residue.

[0011] Secondly, this invention provides a method for preparing a compound protein feed specifically for fur-bearing animals, comprising differentiated pretreatment of raw materials and segmented compound enzymatic hydrolysis, including the following steps:

[0012] S1. Raw material differentiation and selection pretreatment:

[0013] S2. Differentiated sterilization treatment of raw materials:

[0014] S3, Differentiated multi-stage particle size grinding and homogenization treatment of raw materials;

[0015] S4, Two-step gradient complex enzyme modification treatment:

[0016] S5. Curing, drying, cooling and packaging.

[0017] Furthermore, the raw material differentiation selection pretreatment mentioned in step S1 refers to the present invention strictly screening raw materials that meet the various indicators, controlling the initial moisture content of all raw materials to ≤7%, and ensuring that the raw materials are free from mold, oxidation, Salmonella, and excessive mold.

[0018] Among them, feather meal removes hard feather shafts and coarse fiber impurities, retaining only pure feather keratin components; blood meal pre-removes free volatile fishy-smelling substances from the surface; amino acid residue is dehumidified and then broken up to remove clumps and oxidized ineffective materials; black soldier fly powder and yellow mealworm powder remove coarse insect shells and inorganic residues, retaining highly active insect protein.

[0019] Further, the differentiated sterilization treatment of raw materials in step S2 includes: sterilizing the feather meal and blood meal treated in S1 at 90-95℃ for 12-16 minutes to fully remove the fishy smell and kill deep-seated pathogens; sterilizing the black soldier fly powder and yellow mealworm powder at 82-88℃ for 8-12 minutes to inhibit bacteria and remove the fishy smell while retaining the activity of insect peptides; sterilizing the amino acid residue at 78-83℃ for 6-10 minutes to kill surface bacteria and protect free amino acids from decomposition; after sterilization, each raw material is separated and naturally cooled for later use.

[0020] Furthermore, the raw material differential multi-stage particle size crushing and homogenization process described in step S3 is as follows: the feather meal and blood meal treated in S2 are first coarsely crushed to 30-40 mesh; the black soldier fly powder and yellow mealworm powder are crushed to 60-80 mesh; all raw materials are mixed according to their weight proportions and then uniformly fed into an ultra-fine pulverizer, and the final particle size is controlled to be 90-110 mesh. This operation is to reduce the particle size difference of the raw materials and eliminate specific gravity stratification.

[0021] Furthermore, the two-step gradient complex enzyme modification method described in step S4 includes the following steps:

[0022] i. Add 0.15% to 0.25% of alkaline keratinase by total mass of the material to the mixed powder prepared in step S3, adjust the pH of the system to 7.2 to 8.0, seal and keep at a constant temperature of 40 to 44°C, and carry out the enzymatic hydrolysis reaction for 1.5 to 2 hours; during this stage, the disulfide bonds and cross-linked peptide bonds of feather powder keratin are specifically broken, releasing a large amount of hair-promoting sulfur-containing amino acids.

[0023] ii. Continue to add 0.15% to 0.20% of the total material of the complex enzyme (neutral protease: exopeptidase = 1:1) to the system, raise the temperature to 45 to 49°C, and continue enzymatic hydrolysis in a sealed environment for 2 to 2.5 hours; this stage is to degrade blood meal macroglobulin, hydrolyze insect meal crude protein, and dissociate amino acid residue bound small peptides to generate a large number of small molecule growth-promoting peptides and free essential amino acids.

[0024] After enzymatic hydrolysis and modification, feather meal releases a large amount of sulfur-containing amino acids such as cystine, cysteine, and methionine, which serve as the core raw materials for hair keratin synthesis, promoting thicker down, longer guard hairs, and tighter skin.

[0025] After enzymatic hydrolysis, black soldier fly powder and yellow mealworm powder are rich in insect antimicrobial peptides, unsaturated fatty acids, and natural chitin, which improve the intestinal health of fur-bearing animals, alleviate stress-induced hair loss during molting, stimulate sebaceous glands to secrete oil, and enhance the shine and smoothness of fur. At the same time, their amino acid composition matches the growth needs of fur-bearing animals, with a mild flavor that neutralizes the fishy and unpleasant odors of blood meal and feather meal, making them palatable, increasing daily feed intake, and stabilizing the body's basal metabolism.

[0026] The enzymatically hydrolyzed amino acid residue is rich in free methionine, lysine, threonine, and valine, which can compensate for the limiting amino acids lacking in the other four raw materials, achieving a balanced ratio of full-spectrum amino acids and avoiding poor fur development caused by amino acid defects.

[0027] Furthermore, the ripening and drying process described in step S5 is as follows:

[0028] Maturation: The enzymatically hydrolyzed material is fed into a negative pressure sealed mixing vessel and matured at a constant temperature of 42℃ with low-speed stirring at a speed of 260-340 r / min for 25-35 min; the negative pressure environment eliminates air bubbles in the powder, promotes the mutual penetration and compounding of multi-source protein molecules, and stabilizes the overall nutritional system;

[0029] Drying: The drying temperature of this invention does not exceed 53℃ throughout the entire drying process, and it is divided into two stages of stepped heating and drying. The first stage is drying at 40-45℃ for 4-6 hours to slowly remove surface free moisture and lock in the activity of small molecule peptides and free amino acids. The second stage is drying at 48-53℃ for 2-3 hours to deeply remove bound water. After drying, the moisture content of the finished product is controlled at 7.0%-8.5% to avoid high-temperature oxidation and nutrient inactivation.

[0030] Further, the cooling and dispensing process described in step S5 is as follows: the dried material is naturally cooled to room temperature and sieved through a 90-mesh sieve to remove agglomerated coarse particles; after sieving, the powder is transferred to a sealed silo and allowed to stand and stabilize for 24 hours to allow the internal protein complex structure to stabilize, and then the dispensing is completed, and nitrogen is introduced for sealed storage.

[0031] While retaining the five core raw materials—black soldier fly powder, yellow mealworm powder, feather meal, blood meal, and fermented amino acid residue—the addition of trace amounts of minerals, vitamins, probiotics, and other excipients is also within the scope of protection of this invention.

[0032] Thirdly, this invention provides the application of the above-mentioned compound protein feed for fur-bearing animals, especially in the breeding feed for fur-bearing animals such as foxes, raccoons, and minks during their growing and winter fur-bearing periods.

[0033] Furthermore, the compound protein feed of the present invention can improve the growth performance (body weight, feed intake) and feed utilization rate (feed weight ratio) of fur-bearing animals during the rearing period.

[0034] Furthermore, the compound protein feed of the present invention can improve the stress resistance, immunity, protein / fat metabolism capacity, and fur quality of fur-bearing animals during the winter molting period, and shorten the molting cycle.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The compound protein feed for fur-bearing animals described in this invention features a scientifically proportioned blend of ingredients that work synergistically. Its nutritional composition perfectly matches the growth needs of fur-bearing animals, making it suitable for continuous feeding during the rearing and winter molting periods of animals such as mink, foxes, and raccoon dogs. It is highly palatable, increasing daily feed intake and body weight while reducing the feed conversion ratio, stabilizing basal metabolism, enhancing immunity, and improving the absorption and metabolism of protein and fat. Simultaneously, it effectively retains the antimicrobial peptides and unsaturated fatty acids from black soldier flies and mealworms, improving intestinal health, alleviating stress during molting, increasing sebum secretion, and enhancing the oiliness, luster, and smoothness of the fur. The enzymatically hydrolyzed amino acid profile is balanced across the entire spectrum, significantly improving fur quality (down length, guard hair length, and pelt length), shortening the fur maturation cycle, and increasing the economic value of fur-bearing animals. Attached Figure Description

[0037] Figure 1 The results show the effects of different diets on animal immune function indicators during the winter coat period.

[0038] Figure 2 The results show the effects of different diets on animal protein metabolism indicators during the winter coat period.

[0039] Figure 3 The results show the effects of different diets on animal fat metabolism indicators during the winter coat period. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods; unless otherwise specified, the materials and reagents used are commercially available. The feather meal, blood meal, amino acid residue and ordinary feed used in the embodiments of this invention were all purchased from Shandong Linqu Huamao Feed Co., Ltd.

[0042] Example 1

[0043] A compound protein feed for fur-bearing animals, comprising the following components by weight per 100 parts: 25 parts black soldier fly powder, 19 parts yellow mealworm powder, 22 parts feather meal, 16 parts blood meal, and 18 parts amino acid residue.

[0044] The compound protein feed specifically for fur-bearing animals is prepared through the following steps:

[0045] (1) Raw material grading and pretreatment: Screen raw materials that meet the various indicators, control the initial moisture content of all raw materials to ≤7%, and ensure that there is no mold, no oxidative rancidity, no Salmonella, and no excessive mold. Among them, feather meal is separated by airflow to remove hard feather shafts and coarse fiber impurities, retaining only pure feather keratin components; blood meal is pre-treated by low-temperature hot air to remove free volatile fishy smell substances on the surface.

[0046] Amino acid residue is dehumidified at low temperature and mechanically dispersed and de-agglomerated to remove lumpy, oxidized and ineffective materials; black soldier fly powder and yellow mealworm powder are removed by vibrating sieve to remove coarse insect shells and inorganic residues, while retaining highly active insect protein.

[0047] (2) Each material is sterilized at a controlled temperature: Feather meal and blood meal that have been screened in (1) are sterilized at 90℃ for 15 minutes; Black soldier fly powder and yellow mealworm powder are sterilized at 85℃ for 10 minutes; Amino acid residue is treated with antibacterial treatment at 80℃ for 8 minutes; After sterilization, the materials are separated and cooled naturally for later use.

[0048] (3) Multi-stage particle size classification, crushing and homogenization treatment: Feather powder and blood powder after sterilization in (2) are coarsely crushed to 40 mesh, and black soldier fly powder and yellow mealworm powder are crushed to 80 mesh separately. Then, all raw materials are mixed according to the weight parts and sent to an ultra-fine pulverizer. The final particle size is controlled to 100 mesh.

[0049] (4) Segmented compound enzymatic hydrolysis modification: Add 0.2% alkaline keratinase of the total mass of the powder to the pulverized mixture in (3), adjust the pH of the system to 7.5, seal and keep the temperature at 42℃, and hydrolyze for 2 hours; then add 0.18% compound enzyme (neutral protease: exopeptidase = 1:1) of the total mass of the powder to the system, raise the temperature to 47℃, and continue to hydrolyze in a sealed environment for 2 hours;

[0050] (5) Maturation, drying, cooling and packaging: All materials that have been enzymatically hydrolyzed in (4) are sent into a negative pressure closed stirring kettle, and matured at 42℃ with stirring at 300r / min for 30min. After defoaming, two-stage step heating and drying are carried out: pre-drying at 45℃ for 5h and deep drying at 50℃ for 2h. After drying, the material is naturally cooled to room temperature and passed through a 90-mesh precision vibrating screen to remove agglomerated coarse particles. After sieving, the powder is transferred to a closed silo and allowed to stand for 24h. The packaging bag is filled with nitrogen for protection and sealed for storage.

[0051] Example 2

[0052] A compound protein feed for fur-bearing animals, comprising the following components by weight per 100 parts: 20 parts black soldier fly powder, 22 parts yellow mealworm powder, 16 parts feather meal, 19 parts blood meal, and 23 parts amino acid residue.

[0053] The compound protein feed specifically for fur-bearing animals is prepared through the following steps:

[0054] Steps (1), (2), and (3) are the same as in Example 1;

[0055] (4) Segmented compound enzymatic hydrolysis modification: Add 0.15% of the total mass of alkaline keratinase to the mixed powder pulverized in (3), adjust the pH of the system to 7.5, seal and keep the temperature constant at 42℃, and enzymatic hydrolyze for 2h; then add 0.2% of the total mass of compound enzyme (neutral protease: exopeptidase = 1:1) to the system, raise the temperature to 47℃, and continue to enzymatically hydrolyze in a sealed environment for 2h;

[0056] (5) The steps are the same as in Example 1.

[0057] Example 3

[0058] A compound protein feed for fur-bearing animals, comprising the following components by weight per 100 parts: 30 parts black soldier fly powder, 16 parts yellow mealworm powder, 26 parts feather meal, 13 parts blood meal, and 15 parts amino acid residue.

[0059] The compound protein feed specifically for fur-bearing animals is prepared through the following steps:

[0060] (1) Raw material grading and pretreatment: Screen raw materials that meet the various indicators, control the initial moisture content of all raw materials to ≤7%, and ensure that there is no mold, no oxidative rancidity, no Salmonella, and no excessive mold. Among them, feather meal is separated by airflow to remove hard feather shafts and coarse fiber impurities, retaining only pure feather keratin components; blood meal is pre-treated by low-temperature hot air to remove free volatile fishy substances on the surface; amino acid residue is dehumidified at low temperature and mechanically dispersed and de-agglomerated to remove agglomerated and oxidized materials; black soldier fly powder and yellow mealworm powder are separated by vibration screening to remove coarse insect shells and inorganic residues, retaining highly active insect protein.

[0061] (2) Each material is sterilized at a controlled temperature: Feather meal and blood meal that have been screened in (1) are sterilized at 95℃ for 12 minutes; Black soldier fly powder and yellow mealworm powder are sterilized at 88℃ for 8 minutes; Amino acid residue is treated with antibacterial treatment at 83℃ for 6 minutes; After sterilization, the materials are separated and cooled naturally for later use.

[0062] (3) Multi-stage particle size classification, crushing and homogenization treatment: Feather powder and blood powder after sterilization (2) are coarsely crushed to 30 mesh, and black soldier fly powder and yellow mealworm powder are crushed to 60 mesh separately. Then, all raw materials are mixed according to the weight parts and sent to an ultra-fine pulverizer. The final particle size is controlled to 110 mesh.

[0063] (4) Segmented compound enzymatic hydrolysis modification: Add 0.25% of the total mass of alkaline keratinase to the mixed powder pulverized in (3), adjust the pH of the system to 7.5, seal and keep the temperature constant at 42℃, and enzymatic hydrolyze for 2h; then add 0.15% of the total mass of compound enzyme (neutral protease: exopeptidase = 1:1) to the system, raise the temperature to 47℃, and continue to enzymatically hydrolyze in a sealed environment for 2h;

[0064] (5) Maturation, drying, cooling and packaging: All materials that have been enzymatically hydrolyzed in (4) are sent into a negative pressure closed stirring kettle, and matured at 42℃ with stirring at 300r / min for 30min. After defoaming, two-stage step heating and drying are carried out: pre-drying at 45℃ for 5h and deep drying at 50℃ for 2h. After drying, the material is naturally cooled to room temperature and passed through a 90-mesh precision vibrating screen to remove agglomerated coarse particles. After sieving, the powder is transferred to a closed silo and allowed to stand for 24h. The packaging bag is filled with nitrogen for protection and sealed for storage.

[0065] Example 4

[0066] A compound protein feed for fur-bearing animals, comprising the following components by weight per 100 parts: 30 parts black soldier fly powder, 12 parts yellow mealworm powder, 26 parts feather meal, 19 parts blood meal, and 13 parts amino acid residue.

[0067] The compound protein feed specifically for fur-bearing animals is prepared through the following steps:

[0068] Steps (1), (2), and (3) are the same as in Example 3;

[0069] (4) Segmented compound enzymatic hydrolysis modification: Add 0.20% of the total mass of alkaline keratinase to the mixed powder pulverized in (3), adjust the pH of the system to 7.5, seal and keep the temperature at 42℃, and enzymatic hydrolyze for 2 hours; then add 0.18% of the total mass of compound enzyme (neutral protease: exopeptidase = 1:1) to the system, raise the temperature to 47℃, and continue to enzymatically hydrolyze in a sealed environment for 2 hours;

[0070] (5) The steps are the same as in Example 3.

[0071] Comparative Example 1

[0072] A compound protein feed for fur-bearing animals, comprising the following components by weight per 100 parts: 25 parts black soldier fly powder, 19 parts yellow mealworm powder, 22 parts feather meal, 25 parts blood meal, and 9 parts amino acid residue.

[0073] The preparation method of the compound protein feed for fur-bearing animals is the same as in Example 1.

[0074] Comparative Example 2

[0075] The raw materials for the compound protein feed for fur-bearing animals described in Example 1 are the same, except that the preparation step (4) is: add 0.18% of the total material of the compound enzyme (neutral protease: exopeptidase = 1:1) to the system, seal and keep at a constant temperature of 47°C, adjust the pH of the system to 7.5, and continue to seal and enzymatically hydrolyze for 2 hours; that is, the first step of alkaline keratinase hydrolysis process is omitted.

[0076] Comparative Example 3

[0077] The raw materials for the compound protein feed for fur-bearing animals described in Example 1 are the same, except that the preparation step (4) is: add 0.2% of the total mass of alkaline keratinase to the mixed powder pulverized in (3), adjust the pH of the system to 7.5, seal and keep at a constant temperature of 42°C, and enzymatically hydrolyze for 2 hours; that is, the second step of enzymatic hydrolysis of neutral protease and exopeptidase complex enzyme is omitted.

[0078] Comparative Example 4

[0079] The raw materials are the same as those for the compound protein feed for fur-bearing animals described in Example 1. The only difference is that the pretreatment steps (1), (2), and (3) are omitted in the preparation method. The raw materials are simply mixed by mechanical stirring before proceeding to operations (4) and (5).

[0080] The present invention conducted animal feeding trials on the various groups of compound protein feeds specifically for fur-bearing animals prepared in the examples and comparative examples.

[0081] Application Trial

[0082] Experiment location: A fur-bearing animal farm in Liaocheng City, Shandong Province

[0083] Feeding and management: Healthy and active weaned raccoon pups of the same age with no significant difference in weight were selected and randomly divided into 9 groups of 12 pups each. One pup per cage was considered a replicate. Throughout the experimental period, the pups were fed by fixed caretakers on a free-feeding basis. The feeding environment of each treatment group was kept consistent. After a week of pre-feeding with the same feed, the group feeding experiment was carried out during the rearing period (from August 11, 2025 to September 21, 2025, a total of 42 days) and the winter fur period (from September 22, 2025 to December 20, 2025, a total of 90 days).

[0084] The nine experimental raccoon dogs were fed the feeds prepared for Examples 1-4 and Comparative Examples 1-4, respectively. The control group was fed ordinary feed (mainly made from extruded corn, extruded soybean meal, DDGS, corn germ cake, fish meal, and meat and bone meal). During the feeding period, each group was fed twice a day. Feed was weighed and fed separately according to the feeding situation of each raccoon dog. They had free access to water, natural light, and their enclosures were cleaned regularly to minimize the impact of feeding and management on the experimental raccoon dogs.

[0085] 1. Effects on growth performance during the rearing period (growing period)

[0086] Growth performance index determination:

[0087] (1) Average daily weight gain: The raccoon dogs were weighed on an empty stomach at the beginning and end of the experiment to calculate the average daily weight gain.

[0088] Average daily weight gain = (final weight - initial weight) / number of days of rearing.

[0089] (2) Average daily food intake: Record the daily food intake of the experimental raccoon dogs and calculate the average daily food intake.

[0090] (3) Calculation of material weight ratio: Total material consumption / (final weight - initial weight).

[0091] The statistical calculation results of the measured data are shown in Table 1.

[0092] Table 1

[0093] As shown in Table 1, the feed of the present invention significantly improved the average daily feed intake and daily weight gain of the experimental raccoons, and reduced the feed conversion ratio. This indicates that the feed ingredients used in the present invention, through scientific formulation and optimized preparation process, can synergistically improve the growth performance and feed utilization of the experimental raccoons. Compared with other comparative groups, the example group increased the feed intake and weight gain of the experimental raccoons, improved feed utilization, and reduced the feed conversion ratio. In contrast, in Comparative Example 1, the ingredient ratio was changed, with excessive / insufficient amounts of blood meal and amino acid residue, resulting in poor palatability and reduced weight. Although blood meal has a high crude protein content, it has a strong, pungent odor, which can cause fur-bearing animals to refuse or be picky eaters, leading to reduced feed intake and decreased feed utilization. In Comparative Example 2, the main component of feathers is highly cross-linked keratin, and the large number of disulfide bonds between molecules are difficult for endogenous digestive enzymes in animals to break down. Omitting the enzymatic hydrolysis step resulted in reduced feed utilization. In Comparative Example 3, the second enzymatic hydrolysis step was omitted. Blood meal had poor palatability, an unbalanced amino acid structure, and high hygroscopicity. Simple mixing and piling easily led to clumping, oxidation, and mold growth, resulting in rapid decomposition and loss of free amino acids, making it impossible to stably supply nutrients for growth. The effective active substances in black soldier fly meal and yellow mealworm meal could not be effectively retained, leading to decreased growth performance and reduced feed utilization in fur-bearing animals. In Comparative Example 4, the single physical mixing process easily resulted in stratification and uneven nutrition. Insect meal was lightweight, while blood meal and feather meal were heavy, and amino acid residue easily agglomerated. Ordinary stirring could not achieve homogeneous integration, leading to large fluctuations in nutrient intake during feeding and significant differences in body weight and feed conversion ratio among individuals in the same batch.

[0094] 2. Effects of winter coat period on animal immunity and metabolic function

[0095] At the end of the experiment, 10 mL of blood was collected from the hind limb veins of the raccoon dogs on an empty stomach in the morning. The blood was centrifuged at 4000 r / min for 15 min to prepare serum, which was then frozen at -20℃ for analysis of the content of serum biochemical indicators.

[0096] The blood biochemical indicators used in the experiment, such as total protein (TP), albumin (ALB), blood urea nitrogen (BUN), triglycerides (TG), total cholesterol (TC), immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG), were measured according to the instructions of the purchased reagent kit.

[0097] Indicators affecting the immune function of experimental raccoons include: IgA, IgM, and IgG. Statistical results are as follows: Figure 1 As shown.

[0098] Molting is a period of high stress for fur-bearing animals, and one of the main purposes of winter molting feed is to improve the raccoon dog's stress resistance and enhance its immunity. Immunoglobulins in the blood are an important line of defense against pathogenic microorganisms and are a major indicator of the body's immunity. For example... Figure 1 As shown, the activities of IgA, IgM, and IgG in the embodiment group of this invention were all higher than those in the control group and the comparative group, indicating that the feed prepared in the embodiment of this invention can effectively improve the immunity and enhance the stress resistance of raccoons. In the comparative group, due to adjustments in raw material composition or omission of the key enzymatic hydrolysis step in the preparation process, the palatability of the feed decreased, the feed intake of raccoons decreased, the amino acid composition of the feed was insufficient, plasma cells could not synthesize immunoglobulins, and IgA, IgM, and IgG decreased simultaneously.

[0099] Indicators affecting protein metabolism in experimental raccoon dogs include: TP, ALB, and BUN. Statistical results are shown below. Figure 2 As shown.

[0100] Serum albumin (TP) and ALB levels reflect the body's protein absorption and metabolism. For example... Figure 2 As shown, compared with the control and comparative groups, the TP and ALB levels in the embodiment group of this invention were significantly increased, indicating that feeding with the feed prepared according to the embodiment of this invention enhanced the digestion, absorption, and protein metabolism capabilities of raccoon dogs. Protein unsaturated nitrogen (BUN) is produced after protein breakdown and is the end product of the metabolic process, excreted by the kidneys. Its blood concentration reflects the strength of kidney function; low serum BUN levels indicate good kidney function, while high serum BUN levels indicate abnormal kidney function. Compared with the control and comparative groups, the BUN levels in the embodiment group of this invention were significantly lower. The results indicate that the feed of this invention can significantly improve the protein metabolism capacity of raccoon dogs, while also improving kidney function and enhancing the body's ability to utilize protein. Furthermore, protein is one of the main components of animal hair, and the level of protein metabolism will have a certain impact on the performance of animal fur. Improving the protein utilization rate of raccoon dogs is of great significance for improving fur quality.

[0101] Indicators affecting lipid metabolism in experimental raccoons include TG and TC. Statistical results are shown below. Figure 3 As shown.

[0102] Figure 3 The results showed that, compared with the control and comparative groups, the TG and TC levels in the experimental group were significantly lower, indicating that the feed of the present invention improved the absorption and metabolism of fat in the experimental raccoon dogs. The level of fat absorption and metabolism has a significant impact on the color and gloss of animal fur; therefore, improving the utilization of lipids by animals is crucial for the production of high-quality fur.

[0103] 3. The impact of the winter fur season on fur quality

[0104] Each experimental raccoon was fed until its winter fur matured, then euthanized and its pelt was flattened and its length from the tip of the nose to the base of the tail was measured. The length of the needle and down was measured at each point on the back, abdomen, and neck of the pelt. The statistical results are shown in Table 2.

[0105] Table 2

[0106] Table 2 shows that the production performance of raccoon dogs is mainly reflected in the quality of their fur. The main indicators used in this invention to measure raccoon dog fur are pelt length, guard hair length, and underfur length. The raccoon dogs in the example group of this invention showed higher levels of all fur indicators than the control group and the comparative group. Based on the previous results, it can be inferred that the raccoon dog's feed intake, immunity, and utilization rate of protein and fat are all important factors affecting fur quality.

[0107] Comparative Example 1: Excessive or insufficient use of blood meal and amino acid residue leads to poor palatability, reduced body weight and immunity. While blood meal has a high crude protein content, it also has a strong, pungent, and fishy odor. Adding large proportions can cause fur-bearing animals to refuse to eat or become picky eaters, resulting in dry fur and sparse down. Comparative Example 2: Feather meal is not enzymatically hydrolyzed, resulting in extremely low utilization. Feathers are primarily composed of highly cross-linked keratin, with numerous disulfide bonds between molecules that are difficult for endogenous digestive enzymes in animals to break down. Conventional crushing and simple heat treatment only achieve physical fragmentation, resulting in insufficient release of cystine and homocysteine. A large amount of core amino acids for long-hair growth are excreted in feces, leading to high input costs and weak down-promoting effects. In Comparative Example 3, the blood meal, amino acid residue, and insect meal were not enzymatically hydrolyzed, resulting in poor palatability, an imbalanced amino acid structure, a lack of sulfur-containing amino acids leading to low utilization, and a distinct fishy odor. After two months of storage at room temperature, oxidation and clumping occurred. The lack of antimicrobial peptides, chitin, and polyunsaturated fatty acids from black soldier fly and yellow mealworm enzymatic hydrolysis caused severe intestinal stress in animals during molting. Simultaneously, the amino acid residue, rich in free amino acids and microbial peptides, was highly hygroscopic, easily clumping, oxidizing, and breeding mold with simple mixing. Free amino acids rapidly decomposed and were lost, failing to provide a stable supply of nutrients for hair follicle growth. After feeding, fur-bearing animals exhibited hair loss, sparse down, and dry fur. Comparative Example 4, without differentiated pretreatment, suffered from stratification and uneven nutrition due to the single physical mixing process: Insect meal was lightweight, blood meal and feather meal were heavy, and amino acid residue easily agglomerated; ordinary stirring could not achieve homogeneous integration, resulting in large fluctuations in nutrient intake during feeding and significant differences in fur quality among individuals from the same batch.

[0108] Through visual observation and tactile evaluation, fur quality was classified into three grades: fur color into bluish-gray, grayish-yellow, and grayish-white; density into dense, slightly sparse, and sparse; guard hair evenness into even, slightly uneven, and uneven; and back and belly hair differences (length and color) into small, large, and excessive differences. The example group showed significantly better fur feel, softness, color gloss, and fur density than the control and comparative groups, indicating that the feed of this invention has a significant effect on improving fur quality. Furthermore, the experiment found that the winter pelts of the raccoon dogs fed the example group matured earlier than those of the control and comparative groups, meaning the example group promoted fur growth and shortened the molting cycle.

[0109] Obviously, the specific implementation schemes described above are merely a further detailed explanation of the purpose, technical solution and beneficial effects of the present invention. It should be understood that the above descriptions are only specific examples of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A compound protein feed specifically for fur-bearing animals, characterized in that, The raw materials, by weight, include the following components: 20-30 parts black soldier fly powder, 12-22 parts yellow mealworm powder, 16-26 parts feather meal, 11-19 parts blood meal, and 13-23 parts amino acid residue.

2. The method for preparing a compound protein feed specifically for fur-bearing animals as described in claim 1, characterized in that, Includes the following steps: S1. Differentiated selection and pretreatment of raw materials: control the initial moisture content of all raw materials to ≤7%, and ensure that the raw materials are free from mold, oxidation, Salmonella, and excessive mold. S2. Independent temperature-controlled sterilization of each raw material: S3. After each raw material is pulverized into multiple particle sizes, it is mixed according to the formula and then the particle size is uniformly controlled to be 90-110 mesh. S4. Two-step segmented complex enzyme hydrolysis: First, add alkaline keratinase to the mixed powder prepared in step S3. After the hydrolysis is completed, add the complex enzyme to react. S5. Curing, drying, cooling and packaging.

3. The preparation method according to claim 2, characterized in that, The pretreatment in step S1 also includes removing hard feather shafts and coarse fiber impurities from feather meal; pre-removing surface free volatile fishy-smelling substances from blood meal; dehumidifying and breaking up amino acid residue, and sieving out clumps; and removing coarse shells and inorganic residues from black soldier fly powder and yellow mealworm powder, while retaining highly active insect protein.

4. The preparation method according to claim 2, characterized in that, The specific operation of independent temperature-controlled sterilization in step S2 is as follows: the feather meal and blood meal screened in S1 are sterilized at 90-95℃ for 12-16 minutes, the black soldier fly meal and yellow mealworm meal are sterilized at 82-88℃ for 8-12 minutes, and the amino acid residue is sterilized at 78-83℃ for 6-10 minutes.

5. The preparation method according to claim 2, characterized in that, The multi-stage particle size crushing and homogenization process in step S3 involves first coarsely crushing the feather meal and blood meal after the treatment in S2 to 30-40 mesh; and crushing the black soldier fly powder and yellow mealworm powder to 60-80 mesh.

6. The preparation method according to claim 2, characterized in that, The two-step segmented complex enzyme hydrolysis process described in step S4 is as follows: i. Add 0.15% to 0.25% of alkaline keratinase by total mass of the material to the mixed powder prepared in step S3, adjust the pH of the system to 7.2 to 8.0, keep the temperature at 40 to 44°C, and carry out the enzymatic hydrolysis reaction for 1.5 to 2 hours; ii. Continue to add 0.15% to 0.20% of the total material of the compound enzyme to the system, raise the temperature to 45 to 49°C, and enzymatically hydrolyze for 2 to 2.5 hours.

7. The preparation method according to claim 2, characterized in that, The complex enzyme is a combination of neutral protease and exopeptidase in a mass ratio of 1:

1.

8. The preparation method according to claim 2, characterized in that, The ripening and drying process described in step S5 is as follows: the material that has been enzymatically hydrolyzed in step S4 is ripened at a constant temperature of 42°C with low-speed stirring at a speed of 260-340 r / min for 25-35 min. After defoaming, it is dried in the first stage at 40-45°C for 4-6 h, and then dried in the second stage at 48-53°C for 2-3 h.

9. The application of the compound protein feed for fur-bearing animals as described in claim 1 in improving the growth performance and feed utilization rate of fur-bearing animals during the rearing period.

10. The application of the compound protein feed for fur-bearing animals as described in claim 1 in improving the immunity, protein / fat metabolism capacity, and fur quality of fur-bearing animals during winter fur season.

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