A rodenticide and a method of preparing the same

Abstract

This invention relates to the field of rodenticide technology, specifically to a rodenticide bait and its preparation method. The rodenticide bait comprises, from the inside out, a poison core particle, a feeding attractant carrier layer coated on the poison core particle, and a functional composite coating layer coated on the feeding attractant carrier layer. The raw materials of the poison core particle include rodenticide active ingredients, a gelling framework, and a stabilizing system. The rodenticide active ingredients include vitamin D3 and calcium salts. The raw materials of the feeding attractant carrier layer include a grain by-product carrier, feeding attractant ingredients, palatability agents, excipients, and safety markers. This invention solves the problem of vitamin D3 deterioration and inactivation through a quadruple protection mechanism of "oil hydrophobic barrier - calcium ion cross-linked gel network - weakly alkaline microenvironment - internal antioxidant," while significantly increasing the active feeding rate of rats by utilizing the natural feeding attractant functions of sugarcane molasses and other substances.

Description

Technical Field

[0001] This invention relates to the field of rodenticide technology, specifically to a rodenticide bait and its preparation method. Background Technology

[0002] VD3 (also known as cholecalciferol) rodenticides utilize the fact that rodents have significantly lower tolerance to VD3 than other animals. They exert their rodenticidal effect by inducing hypercalcemia and multiple organ failure in rats. They possess significant advantages such as a unique mechanism of action, no cross-resistance, safety for non-target organisms, and easy degradation in the environment. As a novel biochemical pesticide, VD3 has been approved for use in organic agricultural production, aligning with the policy direction of green and high-quality development in the pesticide industry. It is also an internationally recognized green solution that can replace traditional anticoagulant rodenticides.

[0003] However, the use of VD3 in China is currently limited. Besides its relatively high production cost compared to other rodenticides, there are two main reasons: First, existing products have poor palatability for rats, easily leading to them refusing to eat them. Second, the core active ingredient, VD3, is sensitive to oxygen, acidic or humid environments, as well as light and heat. It is particularly prone to isomerization and inactivation under weakly acidic conditions. Since most rodenticide baits are made from grain-processed ingredients, they slowly ferment and become acidic, causing rapid deterioration during production, processing, and storage. Especially after the product is placed in the rodent control area, it deteriorates and becomes inactive too quickly due to the influence of external environmental factors such as humidity and oxygen. Therefore, there is currently a lack of VD3 rodenticide baits that possess both excellent palatability and good stability for rats, along with their corresponding preparation technology.

[0004] In view of the above problems, the present invention provides a rodent bait and a method for preparing the same. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a rodent bait and its preparation method.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, a rodenticide bait, the rodenticide bait comprising, from the inside out, a poison core particle, an attractant carrier layer coated on the poison core particle, and a functional composite coating layer coated on the attractant carrier layer; The raw materials of the toxic core particles include rodenticide active ingredients, a gelling skeleton, and a stabilizing system. The rodenticide active ingredients include vitamin D3 and calcium salts; the stabilizing system includes oils, internal antioxidants, and excipients. The raw materials for the palatability-enhancing carrier layer include grain by-product carriers, palatability-enhancing ingredients, palatability agents, excipients, and safety labeling agents; The raw materials for the functional composite coating layer include at least two of the following: paraffin wax, microcrystalline wax, beeswax, palm wax, shellac, hydrogenated palm oil, and animal fats.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the gelling skeleton includes at least one of low-ester pectin, xanthan gum, and gelatin; The excipients in the stable system include at least one of microcrystalline cellulose, starch dextrin, maltodextrin, and pregelatinized starch; The calcium salt includes at least one of calcium hydrogen phosphate, calcium dihydrogen phosphate, calcium citrate, calcium gluconate, calcium carbonate, and calcium lactate. The oils include at least one of peanut oil, soybean oil, palm oil, rapeseed oil, tallow, and chicken fat; The internal antioxidants include at least one of vitamin E (tocopherol), tert-butylhydroquinone (TBHQ), tea polyphenol palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), rosemary extract, and carotenoids.

[0009] Furthermore, the palatability-enhancing ingredients include natural food powders and palatability-enhancing oils; The palatability agents include salts and sugars; The safety labeling agents include bittering agents and visual warning pigments.

[0010] Furthermore, the grain by-product carrier includes at least one of rice bran, wheat bran, peanut meal, and soybean meal; The natural food powder includes at least one of whole milk powder, peanut powder, sesame powder, fish powder, and chicken powder; The palatable oils include at least two of peanut oil, palm oil, refined chicken fat, and butter; The salts include at least one of table salt and monosodium glutamate; The sugars include at least one of sucrose, beet molasses, and cane molasses; The excipients in the feeding-enhancing carrier layer include at least one of microcrystalline cellulose, starch dextrin, maltodextrin, and pregelatinized starch; The bittering agent is benzyl dinatamine; The visual warning pigments include at least one of eosin, red and blue ink, methylene blue, and brilliant blue aluminum lake.

[0011] Furthermore, based on the total weight of the toxic core particles, the toxic core particles comprise the following raw materials in parts by weight: 0.05-0.2 parts vitamin D3, 1-5 parts calcium salt, 1-6 parts oil, 0.5-3 parts low-ester pectin, 0.1-2 parts xanthan gum, 0.01-0.5 parts internal antioxidant, and 5-20 parts excipients.

[0012] Furthermore, based on the total weight of the palatability-enhancing carrier layer, the palatability-enhancing carrier layer comprises the following raw materials in parts by weight: 55-75 parts grain by-product carrier, 4-10 parts natural food powder, 5-15 parts palatability-enhancing oil, 5-25 parts sugar, 0.05-0.5 parts salt, 0.0001-0.002 parts bittering agent, and 0.001-0.01 parts visual warning pigment. Among the 4-10 parts of natural food powder, there are 2-5 parts whole milk powder and 2-5 parts peanut powder and / or fish meal and / or chicken meal.

[0013] Furthermore, based on the total weight of the functional composite coating layer, the functional composite coating layer comprises the following raw materials in parts by weight: 50-80 parts paraffin wax, 15-40 parts beeswax or hydrogenated palm oil, and 5-10 parts animal fat. It is noted that the functional composite coating layer may also contain 0.0001-0.002 parts bittering agent and 0.001-0.01 parts visual warning pigment.

[0014] Secondly, the preparation method of rodenticide bait includes the following steps: S1: A dry-based mixture is obtained by mixing vitamin D3, calcium salt, excipients and internal antioxidants; oil is heated and melted and then added to a gelling skeleton to form a gel; the gel is mixed with the dry-based mixture to form a paste; the paste is granulated, cured and dried to obtain toxic core particles; S2: Mix the grain by-product carrier, natural food powder, palatability agent, and safety labeling agent evenly to obtain a compound attractant dry powder; place the poison core particles in a coating device, alternately spray the adhesive solution and roll the compound attractant dry powder to coat the surface of the poison core particles with an attractant carrier layer; press and dry to obtain a primary rodent bait; S3: Mix and melt paraffin wax, beeswax or palm wax, and animal fat to obtain a composite wax liquid; place the primary rodenticide bait in a coating device, uniformly coat the surface of the primary rodenticide bait with the composite wax liquid, and cool and solidify to obtain the rodenticide bait.

[0015] Furthermore, the moisture content of the poison core particles in step S1 is not higher than 8%, and the particle size of the poison core particles is 2~8mm.

[0016] Furthermore, the adhesive solution in step S2 is a pregelatinized starch paste with a mass concentration of 5% to 15%; the drying in step S2 is drying at 40 to 55°C until the moisture content is less than 10%; the unit weight of each primary rodenticide bait is 5 to 25 g; The composite wax liquid described in step S3 is applied by spraying or dipping.

[0017] The beneficial effects of this invention are: (1) Significantly improved stability of active ingredients: This invention constructs a multi-synergistic stabilization system in the core particles. Among them, the oil coating layer forms a hydrophobic physical barrier to isolate oxygen; the three-dimensional gel network formed by the cross-linking of low-ester pectin and calcium ions physically "locks" the active ingredients; the weakly alkaline calcium salt neutralizes acidic substances and maintains an alkaline microenvironment; and the internal antioxidant scavenge free radicals. The above-mentioned four-fold protection mechanism of "oil hydrophobic barrier - calcium ion cross-linked gel network - weakly alkaline microenvironment - internal antioxidant" fundamentally solves the problem of degradation and inactivation of VD3 during processing and storage.

[0018] (2) Significantly enhanced trapping efficiency: Sugarcane molasses is uniquely introduced as a functional attractant-binding component, using its rich sweet and caramel flavor to mask the unpleasant astringent taste of calcium salts and drugs; combined with the natural grain aroma and natural strong attractant components of grain by-products, it forms a multi-dimensional attraction to the smell and taste of pests, significantly increasing the active feeding rate; the calcium source and VD3 precisely matched in the poison core can work synergistically in the body of pests to accelerate the process of hypercalcemia and effectively shorten the lethal time.

[0019] (3) Wider range of environmental adaptability: The functional composite coating layer provides better moisture protection and avoids the bait from becoming loose or powdery after absorbing moisture. It is not only suitable for various indoor environments such as food processing plants and farms, but also for various outdoor environments such as communities, vegetable gardens, woodlands, and pastures.

[0020] (4) Significantly reduced overall cost: Sugarcane molasses and agricultural by-products such as rice bran, wheat bran, peanut meal, and soybean meal are fully utilized as the main base material for bait. Sugarcane molasses plays a dual role in attracting food and binding, eliminating the need for external chemical binders and significantly reducing raw material costs.

[0021] (5) Improved safety performance: With VD3 as the active ingredient, it has the inherent advantages of no cross-resistance, safety for non-target organisms, and easy degradation in the environment. Benzyl denatamine (a potent bittering agent) and brilliant blue aluminum lake (a long-lasting blue pigment) are added to the outer carrier and coating of the bait to establish a dual safety warning label based on both taste and sight. Attached Figure Description

[0022] Figure 1 This is the HPLC chromatogram of VD3 standard. Figure 2 The results of vitamin D3 content test after the bait prepared by the method of this patent was placed for 30 days; Figure 3 The results of vitamin D3 content test after the bait prepared by the method of this patent was stored for 60 days; Figure 4 The results of vitamin D3 content test after 30 days of storage for bait prepared by traditional methods; Figure 5 Results of Vitamin D3 Content Test for Bait Prepared by Traditional Methods After 60 Days of Storage Detailed Implementation

[0023] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they should be performed according to the techniques or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0024] Materials, reagents, and their sources: VD3 (white crystalline solid, purity ≥99%); dicalcium phosphate, citric acid, light calcium carbonate, and calcium lactate are food-grade powders; low-ester pectin (esterification degree <50%), xanthan gum, and gelatin are food-grade powders; vitamin E is feed-grade tocopherol; butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are food-grade antioxidants with a content ≥95%; pregelatinized starch (from corn or cassava) is food-grade; sucrose syrup and cane molasses are... Food grade; all grain by-products are feed grade, passing through a 60-mesh sieve; corn flour, peanut flour, fish meal, and chicken meal are food grade powders, passing through an 80-mesh sieve; monosodium glutamate, edible salt, and whole milk powder are food grade, passing through an 80-mesh sieve; vegetable and animal oils are all food grade, refined oils; denatum benzoate is a food grade bittering agent with a purity ≥98%; brilliant blue aluminum lake is a food grade pigment; paraffin wax and other waxes are food grade; 75% ethanol is food grade; pure water has a conductivity ≤5.1 µS / cm. All reagents and materials were purchased from major domestic reagent or food companies.

[0025] This embodiment relates to a rodenticide bait, which comprises, from the inside out, a poison core particle, a feeding attractant layer coated on the poison core particle, and a functional composite coating layer coated on the feeding attractant layer; The raw materials of the toxic core particles include rodenticide active ingredients, a gelling skeleton, and a stabilizing system. The rodenticide active ingredients include vitamin D3 and calcium salts; the stabilizing system includes oils, internal antioxidants, and excipients. The raw materials for the palatability-enhancing carrier layer include grain by-product carriers, palatability-enhancing ingredients, palatability agents, excipients, and safety labeling agents; The raw materials for the functional composite coating layer include at least two of the following: paraffin wax, microcrystalline wax, beeswax, palm wax, shellac, hydrogenated palm oil, and animal fats.

[0026] In this preferred embodiment, the gelling skeleton includes at least one of low-ester pectin, xanthan gum, and gelatin; The excipients in the stabilizing system include at least one of microcrystalline cellulose, starch dextrin, maltodextrin, and pregelatinized starch; preferably pregelatinized starch, which has good cold water properties, adhesiveness and plasticity, can effectively adsorb oils and colloids, promote the formation of homogeneous and easily moldable wet materials, and impart suitable hardness and density to the dried toxic core particles, which is conducive to the smooth progress of subsequent coating processes and prevents the particles from breaking during the coating process.

[0027] The calcium salt includes at least one of calcium hydrogen phosphate, calcium dihydrogen phosphate, calcium citrate, calcium gluconate, calcium carbonate, and calcium lactate. The oils include at least one of peanut oil, soybean oil, palm oil, rapeseed oil, tallow, and chicken fat; The internal antioxidants include at least one of vitamin E (tocopherol), tert-butylhydroquinone (TBHQ), tea polyphenol palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), rosemary extract, and carotenoids.

[0028] In this preferred embodiment, the palatability-enhancing ingredients include natural food powder and palatability-enhancing oils; The palatability agents include salts and sugars; The safety labeling agents include bittering agents and visual warning pigments.

[0029] The grain by-product carrier includes at least one of rice bran, wheat bran, peanut meal, and soybean meal; the natural food powder includes at least one of whole milk powder, peanut powder, sesame powder, fish meal, and chicken meal; the palatable oil includes at least two of peanut oil, palm oil, refined chicken oil, and tallow; the salt includes at least one of table salt and monosodium glutamate; the sugar includes at least one of sucrose, beet molasses, and cane molasses; the excipient in the palatable carrier layer includes at least one of microcrystalline cellulose, starch dextrin, maltodextrin, and pregelatinized starch; the bittering agent is denatum; and the visual warning pigment includes at least one of eosin, red and blue ink, methylene blue, and brilliant blue aluminum lake.

[0030] The bittering agent is denaphalonamine. By adding this bittering agent, the extreme sensitivity and aversion to bitterness in humans and most mammals (such as cats, dogs, pets, and livestock) is utilized to trigger a strong "rejection" reflex upon accidental ingestion, thus preventing the ingestion of toxic bait. Furthermore, denaphalonamine is one of the strongest known bitter compounds, providing an immediate and strong taste warning to humans and most animals, while having almost no effect on palatability in rodents such as mice. The visual warning pigment is preferably brilliant blue aluminum lake. Brilliant blue aluminum lake is a stable, water-insoluble, food-grade aluminum lake pigment. It is not prone to color migration, diffusion, or fading during bait processing, subsequent storage, and field deployment, providing a long-lasting, bright, and conspicuous blue visual warning, effectively distinguishing it from the colors of common objects in the natural environment.

[0031] In this preferred embodiment, based on the total weight of the toxic core particles, the toxic core particles comprise the following raw materials in parts by weight: 0.05-0.2 parts vitamin D3, 1-5 parts calcium salt, 1-6 parts oil, 0.5-3 parts low-ester pectin, 0.1-2 parts xanthan gum, 0.01-0.5 parts internal antioxidant, and 5-20 parts excipients. This formulation ensures sufficient calcium source and synergistic effect with vitamin D3 to accelerate the progression of hypercalcemia; the optimized amounts of oil and gelling agent form an effective hydrophobic protective layer on the surface of the active ingredients and construct a gel framework with sufficient mechanical strength; the addition of internal antioxidant provides additional protection against oxidative degradation of the fat-soluble active ingredients; this formulation is the basis for achieving high stability and high efficiency of the toxic core.

[0032] Based on the total weight of the attractant carrier layer, the attractant carrier layer comprises the following raw materials in parts by weight: 55-75 parts grain by-product carrier, 4-10 parts natural food powder, 5-15 parts attractant oil, 5-25 parts sugar, 0.05-0.5 parts salt, 0.0001-0.002 parts bittering agent, and 0.001-0.01 parts visual warning pigment. This clarifies the core composition and proportion of the attractant carrier layer. The high proportion of grain by-products and sugar by-products constitutes the main body of the bait, providing rodents with familiar and appealing sweet tastes, natural grain aromas, and nutritional signals such as plant protein and fat. This significantly reduces the overall cost of the preparation, meeting the economic requirements for large-scale production and large-scale field deployment while ensuring rodent control effectiveness. Simultaneously, it fully utilizes regional resources and reduces dependence on refined grain raw materials and synthetic additives. The extremely low concentration of highly effective bittering agents and eye-catching pigments provides a strong warning effect for humans, livestock, and non-target animals without significantly affecting the feeding preferences of the target rodents, thus greatly improving the safety of use.

[0033] Based on the total weight of the functional composite coating layer, the functional composite coating layer comprises the following raw materials in parts by weight: 50-80 parts paraffin wax, 15-40 parts beeswax or hydrogenated palm oil, and 5-10 parts animal fat. It is noted that the functional composite coating layer may also contain 0.0001-0.002 parts bittering agent and 0.001-0.01 parts visual warning pigment. Paraffin wax, as the main component, provides excellent waterproof sealing; the addition of beeswax or palm wax improves the brittleness of paraffin wax, enhances the toughness, adhesion, and surface gloss of the coating, and its natural crystalline structure helps to form controllable micropores, regulating internal and external gas exchange; tallow, as a plasticizer and flavor supplement, further optimizes the mechanical properties of the coating and provides an auxiliary palatable aroma. This composite system achieves a balance between rigid protection and controlled release.

[0034] In summary, vitamin D3 serves as the core active ingredient in this product within the toxic core particles; calcium salts act as a calcium supplement, accelerating the progression of vitamin D3-induced hypercalcemia and improving rodenticide efficiency; furthermore, the calcium salts themselves provide a weakly alkaline microenvironment, neutralizing any potentially acidic substances and protecting vitamin D3 from acid-induced degradation; the oils are thoroughly mixed with the active ingredients, forming a hydrophobic physical barrier around the vitamin D3 molecules, effectively isolating oxygen and preventing oxidation; and the gelling framework includes food-grade gelling agents such as low-ester pectin, xanthan gum, and gelatin. Low-ester pectin, in the presence of moisture, can bind with calcium... The calcium ions released from the source undergo cross-linking to form a three-dimensional gel network, physically "locking" the active ingredients encapsulated in the oil within. Xanthan gum helps enhance the strength of the particle structure and synergistically maintains the stability of VD3. The preferred internal antioxidant is vitamin E, which has both fat solubility and antioxidant properties, and excellent compatibility with the oil encapsulation layer. It is used to scavenge free radicals, provide internal antioxidant protection, and further prevent the oxidative degradation of VD3. The preferred excipient is pregelatinized starch, which together with the active ingredients, oils, and gelling agents constitutes a highly plastic and structurally stable toxic core particle matrix.

[0035] The grain by-product carrier in the palatability carrier layer provides natural grain aroma, fibrous structure, and oil and water absorption properties, further enhancing palatability and sustained feeding. The palatability component includes a complex flavor enhancement system of salts and sugars, improving overall flavor perception, masking unpleasant tastes, and meeting the physiological needs of rodents. The sugar flavor enhancer, as a basic sweetener, provides a rapid energy signal and is a classic palatability attractant ingredient, simultaneously performing both palatability and binding functions. At least one of sucrose, beet molasses, and cane molasses is preferred. The palatability attractant ingredients include natural food powder and palatable oils. The natural food powder is thoroughly mixed with the outer grain by-product carrier to form a strong palatability attractant carrier, creating a strong, three-dimensional olfactory and gustatory effect on rodents. The bait's attraction and killing efficiency are enhanced by its sensory impact. The attractant oil is preferably a combination of peanut oil and tallow, mixed with the outer grain by-product carrier to improve its palatability and weather resistance, thus increasing its killing efficiency. The safety markings consist of a taste warning unit and a visual warning unit. The taste warning unit is a bittering agent, preferably benzylamine, one of the strongest known bitter compounds, providing an immediate and strong taste warning to most animals, including humans, cats, and dogs, while having almost no effect on rodents such as house mice. The visual warning unit is a pigment additive, preferably brilliant blue aluminum lake, a stable, water-insoluble food-grade pigment that does not easily migrate or fade during storage and application.

[0036] A functional composite coating layer covers the bait carrier layer, forming the outermost protective system of the bait. The functional composite coating is composed of at least two of the following: microcrystalline wax, paraffin wax, beeswax, shellac, hydrogenated palm oil, and animal fats. Paraffin wax serves as the main framework, providing excellent moisture resistance and physical barrier properties. Beeswax or palm wax acts as a toughening and structure modifier, improving the brittleness of pure paraffin wax and enhancing the coating's flexibility and adhesion; its natural microcrystalline structure helps form controllable micro-permeable channels. Butter acts as a plasticizer and auxiliary attractant, further optimizing the coating's mechanical properties and enhancing its adhesion to the bait matrix; its natural flavor also contributes to attracting prey.

[0037] This embodiment also relates to a method for preparing rodenticide bait, including the following steps: S1: A dry-based mixture is obtained by mixing vitamin D3, calcium salt, excipients and internal antioxidants; oil is heated and melted and then added to a gelling skeleton to form a gel; the gel is mixed with the dry-based mixture to form a paste; the paste is granulated, cured and dried to obtain toxic core particles; S2: Mix the grain by-product carrier, natural food powder, palatability agent, and safety labeling agent evenly to obtain a compound attractant dry powder; place the poison core particles in a coating device, alternately spray the adhesive solution and roll the compound attractant dry powder to coat the surface of the poison core particles with an attractant carrier layer; press and dry to obtain a primary rodent bait; S3: Mix and melt paraffin wax, beeswax or palm wax, and animal fat to obtain a composite wax liquid; place the primary rodenticide bait in a coating device, uniformly coat the surface of the primary rodenticide bait with the composite wax liquid, and cool and solidify to obtain the rodenticide bait.

[0038] In this preferred embodiment, the moisture content of the core particles in step S1 is not higher than 8%, and the particle size of the core particles is 2~8 mm.

[0039] In this preferred embodiment, the adhesive solution in step S2 is a pregelatinized starch paste with a mass concentration of 5% to 15%. By adopting the above technical solution, the selected adhesive solution has suitable viscosity and film-forming properties, which can ensure that the composite attractant dry powder adheres firmly to the surface of the poison core particles to form a stable coating layer, and can also maintain a certain degree of flexibility after drying, so as to avoid cracking or peeling of the outer layer due to changes in environmental temperature and humidity or physical compression.

[0040] The drying in step S2 is drying at 40~55°C until the moisture content is less than 10%; the unit weight of each primary rodenticide bait is 5~25 g; the coating method of the composite wax liquid in step S3 is spraying or dipping.

[0041] The coating equipment in step S2 is a sugar coating pan or a fluidized bed coating machine, and the coating equipment in step S3 is a sugar coating pan or a roller coating machine with heating and heat preservation functions. By adopting the above technical solutions and using these conventional and mature pharmaceutical or food processing equipment, it is possible to achieve uniform spraying of coating liquid and wax liquid in steps S2 and S3, and uniform adhesion of powder and coating. The process is highly controllable, the product quality is stable and consistent, and it is suitable for large-scale industrial production.

[0042] This embodiment employs a three-layer structure design and preparation process. First, in step S1, a poison core is constructed with a core stabilizing system consisting of an oil physical barrier and a calcium ion cross-linked gel network. VD3 is efficiently encapsulated within weakly alkaline gel microparticles, fundamentally solving the problems of easy oxidation and rancidity of the active ingredient. Second, in step S2, a precise coating process is used to construct an attractant layer outside the poison core, composed of a high proportion of grain carriers, complex flavor substances, and strong natural palatability-enhancing components, achieving a powerful multi-faceted attraction to the olfactory and gustatory senses of rodents. Notably, sugarcane molasses is innovatively used as a palatability enhancer and binder. Utilizing the natural palatability-enhancing and taste-masking properties of sugarcane molasses, it masks the unpleasant odors of calcium salts and the drug, significantly improving the palatability and active feeding rate of the bait for rodents. Finally, in step S3, a functional coating composed of waxes and oils was explored and applied. This coating layer not only provides excellent physical barriers against moisture and weathering, but its unique microstructure also enables the slow and controlled release of odors and active ingredients from within the bait, further enhancing its long-lasting attractant power and stability in outdoor environments. The three-layer structure has clearly defined functions and synergistic effects, achieving a comprehensive goal of long-lasting stability, high-efficiency attractant killing, environmental friendliness, and safe use.

[0043] The following detailed description uses specific examples, with each example based on the preparation of 1 kg of final bait product.

[0044] Example 1: A method for preparing a rodenticide bait includes the following steps: S1. Preparation of the core granules: Accurately weigh 1.0 g of vitamin D3, 30.0 g of dicalcium phosphate, 100.0 g of pregelatinized starch, 1.0 g of antioxidant, and 15.0 g of sugar. Mix them evenly at low speed using a mixer to obtain a dry base mixture. Weigh 15.0 g of vegetable oil and heat it to 50°C. Weigh 8.0 g of low-ester pectin and 1.6 g of xanthan gum, and dry mix them evenly. Slowly add an appropriate amount of purified water to the mixed gum powder, and stir at high speed for 30 minutes in a 60±5°C water bath until completely dissolved, obtaining approximately 490 g of gelling agent stock solution. Mix the gelling agent stock solution with warm peanut oil and shear at high speed to form a uniform emulsion. Pour this emulsion into the dry base mixture, switch the mixer to medium speed, and stir to form a uniform, highly plastic paste-like core material. Transfer the paste material to an extruder, extrude it into strips with a diameter of approximately 3 mm, and cut them into short cylindrical wet granules. The wet granules were cured at 25°C and 65% relative humidity for 2.5 hours. They were then dried at 50°C until the moisture content was ≤7%, yielding approximately 162 g of poison core granules with a particle size of 3-4 mm.

[0045] S2. Coating and primary shaping of the attractant carrier layer: Weigh 30.0 g of peanut oil and 40.0 g of butter, heat to 50°C and mix well. Separately prepare 20.0 g of an ethanol-water solution containing 10% pregelatinized starch, and stir it evenly with the warm mixed oils to obtain a coating solution. Put 162 g of toxic core particles into a sugar coating pan preheated to 30°C. The coating process is carried out in three stages: First, spray approximately one-third of the coating solution, then slowly add approximately one-third of the compound attractant powder. The compound attractant powder is prepared as follows: Weigh 162.0 g of wheat bran, 162.0 g of peanut meal, 162.0 g of soybean meal, 29 g of whole milk powder, 28.5 g of sucrose, 2.85 g of monosodium glutamate, 9.5 mg of denatumamine benzoate, 47.5 mg of brilliant blue aluminum lake, 130.0 g of sugarcane molasses, and 80.0 g of animal fat. Add these to a mixer and mix for 30 minutes until the color is uniform, yielding approximately 758.5 ​​g of compound attractant powder. Repeat this process until the core particles are completely coated. Press the coated wet particles into coarse flakes of approximately 3-5 g each, and dry them until the moisture content is ≤9%, thus obtaining the primary bait flakes.

[0046] S3. Coating of the functional composite coating layer: Weigh 7.0 g of paraffin wax, 3.0 g of beeswax, and 3.0 g of tallow. Place the paraffin wax and beeswax in a container, heat in a water bath to 85°C to melt and stir evenly. Add the tallow and stir for 10 minutes to form a homogeneous, well-flowing composite wax liquid. Keep it at 75°C for later use. Place the dried primary bait block into a high-efficiency coating machine at 55°C and spray the composite wax liquid, kept at 75°C, evenly onto the surface of the bait block. After cooling, a smooth waxy coating layer is formed on the surface, which is the final bait.

[0047] Example 2: Adjusting the ratio of the poisoned core gel skeleton The difference from Example 1 is that the amount of gelling agent used in Preparation Example 1 is increased, resulting in a low-ester pectin content of approximately 1.6 g and a xanthan gum content of approximately 0.32 g. All other aspects are the same as in Example 1.

[0048] Example 3: Increasing calcium salt content The difference from Example 1 is that the amount of dicalcium phosphate used is 60.0 g. Everything else is the same as in Example 1.

[0049] Example 4: Adjusting the calcium salt composition The difference from Example 1 is that 30.0 g of dicalcium phosphate was replaced with 30.0 g of calcium citrate. Everything else is the same as in Example 1.

[0050] Example 5: Adjusting the composition of calcium salts The difference from Example 1 is that 30.0 g of dicalcium phosphate was replaced with 30.0 g of calcium lactate. Everything else is the same as in Example 1.

[0051] Example 6: Determining the effect of calcium salts The difference from Example 1 is that 30.0 g of dicalcium phosphate was replaced with 30.0 g of pregelatinized starch. Everything else is the same as in Example 1.

[0052] Example 7: Adjusting the composition of the outer palatability attractant The difference from Example 1 is that peanut meal is replaced with fishmeal in equal proportion. Everything else is the same as in Example 1.

[0053] Example 8: Adjusting the composition of the outer palatability enhancer The difference from Example 1 is that peanut meal is replaced with chicken meal in equal proportion. Everything else is the same as in Example 1.

[0054] Example 9: Adjusting the composition of palatability-enhancing oils The difference from Example 1 is that the mixture of 30.0 g of peanut oil and 40.0 g of butter is replaced in equal proportion with a mixture of refined chicken fat and palm oil. Everything else is the same as in Example 1.

[0055] Example 10: Determining the Function of Sugarcane Molasses The difference from Example 1 is that in the preparation of the composite palatability-enhancing dry powder in Example 2, all sugarcane molasses was removed and replaced with an equal amount of carrier powder. Everything else is the same as in Example 1.

[0056] Example 11: Adjusting the composition of the functional coating The difference from Example 1 is that beeswax is replaced with palm wax in equal proportion. Everything else is the same as in Example 1.

[0057] Example 12: Adjusting the composition of the functional coating The difference from Example 1 is that beeswax is replaced with shellac in equal proportion. Everything else is the same as in Example 1.

[0058] Example 13: Without encapsulated toxic core The difference from Example 1 is that the calcium salts, oils, and gelling agents used in the preparation of the poison core in Example 1 are not added, and the poison core is not prepared. Instead, VD3 is directly added and mixed. All dry powder raw materials are directly mixed with an appropriate amount of water, granulated, and dried to prepare the bait. Everything else is the same as in Example 1.

[0059] Example 14: Traditional Mixed Process Bait The difference from Example 1 is that the bait is prepared using a traditional mixing process instead of a poison core preparation and layered preparation process. Calcium salts, oils, gelling agents, antioxidants, vitamin D3, and carrier additives (grain powder, cereals, oats, broken rice) are directly mixed, and then an appropriate amount of ethanol-water solution is added for mixing. The mixture is then directly pressed into shape and dried. All other steps are the same as in Example 1.

[0060] Test case 1. Performance analysis test.

[0061] To verify the technical efficacy of the three-layer VD3 bait of this invention, systematic laboratory and simulated environmental performance tests were conducted on the baits prepared in Examples 1-15 above. All experiments were carried out in accordance with GB / T 27777-2011 "Field Efficacy Determination and Evaluation of Rodenticides" and general industry standards.

[0062] (1) Intake test: Healthy adult Kunming mice (weighing 18-22 g, half male and half female, purchased from Guilin Zhuoyi Biotechnology) were selected and kept at a temperature of 22±2°C and humidity of 40-70%, with 12-12 h light-dark cycles, free access to food and water, and bedding changed every 3 days for 5 days of acclimatization. A completely randomized controlled design was used. Six treatment groups were established (corresponding to Examples 1, 6, 10, 13, and 14, totaling 5 experimental groups, plus a blank control group), with 6 mice in each group housed individually. After the acclimatization period, normal feed was removed, and the corresponding feed was administered at a fixed location in each group using a saturation feeding method, with feed added every 12 h. Indicators were observed and measured, and the consumption and time of death were recorded each time. The total feed intake (g) and number of days since death (d) at the time of death were calculated, and then the average intake (g) and average number of days since death (d) were calculated.

[0063] (2) Simulated field efficacy test: Seven independent, enclosed simulation chambers (each approximately 2 m² in area) were established within a controlled environment simulated field test chamber (temperature: 25±2°C, humidity: 60±10%). 2 The experiment used 10 healthy adult brown rats (approximately 150 g ± 5 g, purchased from Guilin Zhuoyi Biotechnology) in a 1.4 m high enclosure to simulate a warehouse environment. Ten rats were introduced into each enclosure beforehand and allowed to acclimatize for 5 days to establish stable activity and habitat patterns. A saturation feeding method was used to ensure sufficient feed, and remaining feed was weighed periodically to calculate intake. A completely randomized controlled design was employed. The experiment consisted of 6 treatment groups (corresponding to Examples 1, 6, 10, 13, and 14, totaling 5 experimental groups, plus a control group). On day 14 after feeding, the number of active rats in each enclosure was counted, and the 14-day rat density reduction rate (%) was calculated.

[0064] (3) Stability test of VD3, the core component of the bait, in a simulated field environment: The experimental bait samples prepared in each embodiment were subjected to specific stability tests. The specific method was as follows: The bait samples prepared using the method of this patent in Example 1 and the bait samples prepared using the conventional method in Example 14 were placed in a simulated release environment. After 30 days and 60 days respectively, 1 gram of each sample was taken, dissolved in dimethyl sulfoxide, ultrasonically extracted, filtered, and diluted with methanol to obtain the test solution. The content of VD3 was then determined by high-performance liquid chromatography (HPLC). The chromatographic conditions for content analysis were: C18 analytical column, methanol-water (95:5, V:V) as the mobile phase, flow rate 1.0 mL / min, column temperature 35℃, injection volume 100 μL, and UV detection wavelength 264 nm. The retention rate of the active ingredient was determined based on the direct proportionality between the peak height of the VD3 signal in the sample and the VD3 content in the sample. The HPLC chromatograms of the test results are attached. Figure 2-5 The signal peak with a retention time of about 17 minutes in the spectrum is VD3.

[0065] 2. Performance analysis test results.

[0066] (1) Results of intake test: Table 1. Results of intake and time of death in mice in each treatment group (n=6, Mean±SD) Results analysis: Example 1 (Target Formula): The average mortality time of 4.2 days was the shortest among all groups, and the daily food intake of 4.0 g / d was the highest among all groups, indicating that the stabilization of the poison core, calcium synergy, and sugarcane molasses significantly improved palatability and feeding enthusiasm.

[0067] Example 6 (Calcium-free group): The average number of days to death was 5.5 days, and the daily food intake was 3.8 g / day, which was the same as in Example 1, confirming that calcium deficiency does not affect palatability. However, the number of days to death was prolonged to 5.5 days, and the lethal intake was as high as 20.9 g, indicating that the induction of hypercalcemia was slow without calcium supplementation, requiring a greater accumulation of poison bait to cause death, and the inactivation efficacy was significantly reduced.

[0068] Example 10 (No molasses group): Daily food intake decreased to 3.5 g / d, and hesitant eating occurred, confirming the key role of sugarcane molasses in masking the astringent taste of calcium salts and maintaining feeding activity. The time to death was slightly prolonged to 5.0 days, and the lethal intake slightly increased to 17.5 g.

[0069] Example 13 (uncoated poison core group): Daily food intake was 3.3 g / d, the lethal intake was 21.0 g, and the number of days to death was extended to 6.4 days, indicating that the coated poison core is indispensable for maintaining drug efficacy and feeding enthusiasm.

[0070] Example 14 (Traditional Process Group): The palatability was the worst, with a daily feed intake of only 3.1 g / d. The efficiency of feed intake to kill was the lowest, with a mortality period of up to 8.3 days and a total lethal intake of 25.7 g. The process was time-consuming, with low feed intake, resulting in poor actual control effects.

[0071] (2) Results of simulated field efficacy test: Table 2. Results of rat density reduction rate and average number of days to death in each treatment group after 14 days. Results analysis: The dose-response relationship between lethality rate and inactivation efficacy: In Example 1, the mortality time was 5.7 days and the inactivation efficacy was 100%, both of which were optimal. In Examples 6, 10, 13, and 14, the mortality time increased to 7.3 days, 7.8 days, 8.1 days, and 10.4 days respectively, and the rat density reduction rate decreased to 80%, 90%, 90%, and 70% respectively, indicating that core stabilization, calcium synergy, and sugarcane molasses induction also improved the palatability and feeding enthusiasm of brown rats.

[0072] The appetite-enhancing effect of sugarcane molasses: In Example 10 (without sugarcane molasses), the daily food intake was 13.1 g / d, which was 17.1% lower than that of Example 1 (15.8 g / d). The mortality time was extended from 5.7 days to 7.8 days, and the rat density decreased by 90%. This confirms that sugarcane molasses plays an important role in masking the astringent taste of calcium salts, enhancing feeding enthusiasm, and accelerating mortality.

[0073] Synergistic contribution of calcium source and stabilization coating: Example 6 (with coating but no calcium salt) had a daily food intake of 16.3 g / d and an inactivation rate of 80%; Example 13 (without coating but with calcium salt) had a daily food intake of 11.9 g / d and a decrease in rat density of 90%. This indicates that the synergistic effect of VD3 and calcium source is better after the core is coated, and Example 1 combines both and has the best performance.

[0074] Economic evaluation of drug use: In Example 1, 855.1 g was consumed to achieve a 100% reduction in mouse density, directly reflecting the high success rate of attracting feeding. In Example 14, 764.7 g was consumed, but the reduction in mouse density was only 70%, requiring a second dose to remove remaining mice, resulting in higher overall costs. These results are consistent with the trends observed in the mouse experiments in Section 7.6.1, fully validating the high efficiency and applicability of the VD3 rodenticide technology scheme of this invention, which features "stabilized encapsulation of the poison core—synergistic effect of calcium source—compound feeding attraction with sugarcane molasses".

[0075] (3) Stability test results of VD3, the core component of the bait, in a simulated field environment: The results of the retention rate of active ingredients are attached. Figures 1 to 5 The height of the VD3 signal peak corresponds to the relative content of VD3 in the sample. (From the attached...) Figures 1 to 5It can be seen that, compared with the traditional bait manufacturing process, the process method provided by this patent can significantly improve the stability of vitamin D3, the core component of the bait.

[0076] In summary, the rodent bait of the present invention comprises, from the inside out, a poison core particle, a feeding attractant carrier layer, and a functional composite coating layer. The poison core particle contains VD3, calcium salt, an oil coating layer, a gelling skeleton, and an internal antioxidant, forming a multi-layered stable protection system that effectively improves the stability of the core components in the bait and solves the problem of degradation and inactivation of the core active ingredient, VD3. The feeding attractant carrier layer contains feeding attractants such as sugarcane molasses, which significantly improves palatability. At the same time, the natural feeding attractant function of sugarcane molasses also significantly increases the active feeding rate of rats.

[0077] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A rodenticide bait, characterized in that, The rodenticide bait comprises, from the inside out, a poison core particle, an attractant carrier layer coated on the poison core particle, and a functional composite coating layer coated on the attractant carrier layer. The raw materials of the toxic core particles include rodenticide active ingredients, a gelling skeleton, and a stabilizing system. The rodenticide active ingredients include vitamin D3 and calcium salts; the stabilizing system includes oils, internal antioxidants, and excipients. The raw materials for the palatability-enhancing carrier layer include grain by-product carriers, palatability-enhancing ingredients, palatability agents, excipients, and safety labeling agents; The raw materials for the functional composite coating layer include at least two of the following: paraffin wax, microcrystalline wax, beeswax, palm wax, shellac, hydrogenated palm oil, and animal fats.

2. The rodenticide bait according to claim 1, characterized in that, The gelling skeleton includes at least one of low-ester pectin, xanthan gum, and gelatin; The excipients in the stable system include at least one of microcrystalline cellulose, starch dextrin, maltodextrin, and pregelatinized starch; The calcium salt includes at least one of calcium hydrogen phosphate, calcium dihydrogen phosphate, calcium citrate, calcium gluconate, calcium carbonate, and calcium lactate. The oils include at least one of peanut oil, soybean oil, palm oil, rapeseed oil, tallow, and chicken fat; The antioxidants include at least one of vitamin E, tert-butylhydroquinone, tea polyphenol palmitate, butylated hydroxyanisole, di-tert-butylhydroxytoluene, rosemary extract, and carotenoids.

3. The rodenticide bait according to claim 1, characterized in that, The palatability-enhancing ingredients include natural food powders and palatability-enhancing oils; The palatability agents include salts and sugars; The safety labeling agents include bittering agents and visual warning pigments.

4. The rodenticide bait according to claim 3, characterized in that, The grain by-product carrier includes at least one of rice bran, wheat bran, peanut meal, and soybean meal; The natural food powder includes at least one of whole milk powder, peanut powder, sesame powder, fish powder, and chicken powder; The palatable oils include at least two of peanut oil, palm oil, refined chicken fat, and butter; The salts include at least one of table salt and monosodium glutamate; The sugars include at least one of sucrose, beet molasses, and cane molasses; The excipients in the feeding-enhancing carrier layer include at least one of microcrystalline cellulose, starch dextrin, maltodextrin, and pregelatinized starch; The bittering agent is benzyl dinatamine; The visual warning pigments include at least one of eosin, red and blue ink, methylene blue, and brilliant blue aluminum lake.

5. The rodenticide bait according to claim 2, characterized in that, Based on the total weight of the toxic core particles, the toxic core particles comprise the following raw materials in parts by weight: 0.05-0.2 parts vitamin D3, 1-5 parts calcium salt, 1-6 parts oil, 0.5-3 parts low-ester pectin, 0.1-2 parts xanthan gum, 0.01-0.5 parts internal antioxidant, and 5-20 parts excipients.

6. The rodenticide bait according to claim 3, characterized in that, Based on the total weight of the palatability-enhancing carrier layer, the palatability-enhancing carrier layer comprises the following raw materials in parts by weight: 55-75 parts of grain by-product carrier, 4-10 parts of natural food powder, 5-15 parts of palatability-enhancing oil, 5-25 parts of sugar, 0.05-0.5 parts of salt, 0.0001-0.002 parts of bittering agent, and 0.001-0.01 parts of visual warning pigment.

7. The rodenticide bait according to claim 1, characterized in that, Based on the total weight of the functional composite coating layer, the functional composite coating layer comprises the following raw materials in parts by weight: 50-80 parts paraffin wax, 15-40 parts beeswax or hydrogenated palm oil, and 5-10 parts animal fat.

8. A method for preparing rodenticide bait according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1: A dry-based mixture is obtained by mixing vitamin D3, calcium salt, excipients and antioxidants; oil is heated and melted and then added to a gelling skeleton to form a gel; the gel is mixed with the dry-based mixture to form a paste; the paste is granulated, cured and dried to obtain toxic core particles; S2: Mix the grain by-product carrier, natural food powder, palatability agent, and safety labeling agent evenly to obtain a compound attractant dry powder; place the poison core particles in a coating device, alternately spray the adhesive solution and roll the compound attractant dry powder to coat the surface of the poison core particles with an attractant carrier layer; press and dry to obtain a primary rodent bait; S3: Mix and melt paraffin wax, beeswax or palm wax, and animal fat to obtain a composite wax liquid; place the primary rodenticide bait in a coating device, uniformly coat the surface of the primary rodenticide bait with the composite wax liquid, and cool and solidify to obtain the rodenticide bait.

9. The method for preparing the rodenticide bait according to claim 8, characterized in that, The moisture content of the poison core particles in step S1 is not higher than 8%, and the particle size of the poison core particles is 2~8 mm.

10. The method for preparing the rodenticide bait according to claim 8, characterized in that, The adhesive solution in step S2 is a pregelatinized starch paste with a mass concentration of 5% to 15%; the drying in step S2 is drying at 40 to 55°C until the moisture content is less than 10%; the unit weight of each primary rodenticide bait is 5 to 25 g; The composite wax liquid described in step S3 is applied by spraying or dipping.

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