Application method of digestion and emission reduction functional compound preparation for grazing cattle in saline-alkali soil

Abstract

The invention relates to the field of pasturing livestock nutrition and feed resource development, and particularly discloses an application method of a digestion and emission reduction functional composite preparation for pasturing cattle in saline-alkali soil, and the application method comprises the following steps: S1, selecting Allium mongolicum and Stellera chamaejasme as raw materials, and screening an optimal mixing ratio through in vitro rumen fermentation; s2, preparing a granular composite preparation according to the optimal proportion; s3, supplementary feeding is conducted on the saline-alkali land grazing cattle according to the fixed dosage. The method solves the problems of low digestibility and high methane emission of saline-alkali soil grazing cattle due to ingestion of low-quality forage grass, and solves the technical gaps that Allium mongolicum and Stellera chamaejasme are wasted as traditional toxic weed resources, and single grass seeds are difficult to synergistically realize digestion promotion and methane emission reduction, improves the digestibility of saline-alkali soil grazing cattle and nitrogen utilization efficiency, and improves the economic benefit of the saline-alkali soil grazing cattle. Methane emission is synchronously reduced, toxic weeds are converted into functional indigenous grass, the feed source is expanded, the breeding cost is reduced, the technology adapts to the grazing scene, operation is easy and convenient, and large-scale application and popularization are easy.

Description

Technical Field

[0001] This invention relates to the field of livestock nutrition and feed resource development technology, specifically to the application method of a digestive and emission-reducing functional compound preparation for cattle grazing in saline-alkali land, and particularly to a preparation and supplementary feeding program that utilizes a combination of functional native grasses to improve the digestibility of grazing cattle and reduce methane emissions. Background Technology

[0002] The unique ecological environment of saline-alkali land results in a general problem of low biomass, poor nutritional value, and high crude fiber content in forage grasses. This type of low-quality forage grass cannot meet the nutritional needs of grazing cattle, directly causing low dry matter digestibility and insufficient nitrogen utilization efficiency, limiting their growth performance, extending the breeding cycle, and increasing breeding costs. Furthermore, the incomplete fermentation of low-quality forage grass in the gastrointestinal tract further exacerbates methane emissions, bringing additional environmental pressure.

[0003] In addition to traditional edible herbaceous plants and shrubs, saline-alkali pastures also contain some plants that are not favored by grazing livestock. These plants, due to their poor palatability, distinctive odor, thorny stems and leaves, or high content of plant secondary metabolites, are disliked by livestock and have long been considered "poisonous weeds" and eradicated, failing to be effectively developed and utilized, resulting in a potential waste of feed resources. However, these "poisonous weeds," such as Mongolian leek and Daphne odora, contain plant secondary metabolites that are mostly pharmacologically active bioactive compounds, which have the potential to positively impact the productivity and health of grazing livestock, thus belonging to functional native grass resources with development value.

[0004] In the existing technologies, although some studies have focused on the regulatory effect of single functional native grasses on the health of ruminant livestock, there are still significant shortcomings: (1) There is a lack of dedicated technical solutions for the specific breeding scenario of cattle grazing in saline-alkali land and the core problem of pasture nutrient limitation in this scenario; (2) Most studies focus on concentrated feed additives or stall-feeding environments, and their technical paths are incompatible with the free-feeding grazing mode, making it difficult to directly implement them; (3) Plant resources such as Mongolian leek and Daphne odora have a "double nature" - they contain both bioactive components and may contain anti-nutritional factors. Existing technologies lack reliable methodologies and empirical data, making it difficult to exert their synergistic effect of promoting digestion and inhibiting methane production through scientific formulation, while avoiding potential risks; (4) The resource transformation of "toxic weeds" in grazing pastures and the reduction of emissions and efficiency of breeding have not been systematically integrated, and a full-chain solution has not been formed.

[0005] In summary, existing technologies suffer from several problems, including a lack of synergistic regulation between improving the digestibility of cattle grazing in saline-alkali land and reducing methane emissions, ineffective conversion of traditional "toxic weeds" resources, and a lack of compound forage technologies suitable for grazing scenarios. There is an urgent need for a functional compound formulation and application method that can scientifically select grass species ratios, adapt to saline-alkali land grazing scenarios, and realize the resource utilization of "toxic weeds". Summary of the Invention

[0006] In view of the above-mentioned problems in the prior art, the present invention provides an application method of a digestive and emission-reducing functional compound preparation for cattle grazing in saline-alkali land, which solves the synergistic problem of low digestibility and high intestinal methane emissions in cattle grazing in saline-alkali land, and at the same time realizes the resource-efficient utilization of "toxic weeds".

[0007] To achieve the above objectives, this invention proposes a method for applying a digestive and emission-reduction functional compound preparation for cattle grazing in saline-alkali land, comprising: S1. Select Mongolian leek and Daphne odora as raw materials to carry out in vitro rumen fermentation experiment. The experiment will obtain two core parameters: dry matter degradation rate and methane emission under different mixing ratios. S2. Calculate the comprehensive score of different mixing ratios according to the formula, screen out the optimal mixing ratio, and prepare granular compound formulations according to this ratio. The optimal ratio is calculated and screened using the formula: ; In the formula, S is the comprehensive score; DMD is the dry matter degradation rate, %; CH4 is the methane emission, mL / gDM; the ratio corresponding to the maximum value of S is the optimal ratio. S3. Supplement the feed to cattle grazing on saline-alkali land with a fixed dose of compound preparation.

[0008] Preferably, in S1, the in vitro rumen fermentation is constructed based on the Menke in vitro fermentation system, with the following specific conditions: Artificial rumen culture medium was prepared by mixing artificial culture medium with filtered fresh rumen fluid at a volume ratio of 1:2. The artificial culture medium was prepared by mixing the following components per 1 L volume: 237 mL of macro-element solution, 0.12 mL of trace element solution, 237 mL of buffer solution, 50 mL of reducing agent solution, and 1.22 mL of resazurin solution. After mixing, carbon dioxide was bubbled through the mixture until the solution became colorless. Healthy grazing cattle were selected from saline-alkali land. After fasting for 12 hours, rumen fluid was collected. Fresh rumen fluid was obtained by filtering through 4 layers of gauze. Fresh rumen fluid and artificial rumen culture medium were mixed and fermented at the above 1:2 volume ratio. Carbon dioxide was continuously introduced during fermentation to maintain an anaerobic environment. Fermentation temperature 39 The fermentation process was carried out at 0.5℃ for 24 hours. The material to be tested in the fermentation system was the substrate, which was a mixture of Mongolian leek and Daphne odora. The volume-to-mass ratio of the artificial rumen culture medium to the substrate was 40 mL: 1 g. The pH of the system was maintained at 6.5-7.2 during the fermentation process.

[0009] Preferably, in S2, the optimal mixing ratio is the dry weight ratio of Mongolian leek: Daphne odora = 7:3 after drying, which satisfies S ≥ 0.35.

[0010] Preferably, in S3, the fixed dose of the compound preparation is calculated using a supplementary feeding dosage formula, which is: ; In the formula, M is the daily supplemental feed amount, g; k is the supplemental feed dosage coefficient, with a value range of 0.8~1.0 g / kgBW; BW is the weight of the grazing cattle, kg.

[0011] Preferably, in S2, the preparation process of the granular compound formulation includes: raw material drying, pulverization, mixing, granulation, and secondary drying. The pulverization step parameters are: the particle size of the pulverized material is 40 mesh; the moisture content after secondary drying satisfies the formula: ; In the formula, m0 is the mass of the preparation before drying, in g; m1 is the mass of the preparation after drying, in g.

[0012] Preferably, in S2, the granulation pore size is 2~4mm and the granulation pressure is 8~10MPa.

[0013] Preferably, in S3, the supplementary feeding time is 19:00 daily. Supplemental feeding should be done separately for 30 minutes, followed by a 30-minute interval before providing drinking water.

[0014] Preferably, the cattle grazing on saline-alkali land are beef cattle, and the grazing period is from the spring grass greening period to the autumn grass withering period.

[0015] Preferably, in step S2, a binder is added during the mixing process. The binder accounts for 5% of the total dry matter of *Leekia scabra* and *Daphne odora* after drying. The binder is corn starch.

[0016] Preferably, in S1, the raw material is dried at a constant temperature of 65℃ for 48 hours, the particle size of the crushed material is 40 mesh, and the raw material is only collected from the above-ground parts of Mongolian leek and Daphne odora.

[0017] Therefore, this invention proposes an application method for a digestive and emission-reduction functional compound preparation for cattle grazing in saline-alkali land, the beneficial effects of which are as follows: (1) By combining in vitro rumen fermentation with quantitative formulas, the optimal mixing ratio of Mongolian leek and Daphne odora was scientifically screened at 7:3, which effectively avoids the functional limitations of single grass species and the risk of functional offsetting caused by blind mixing ratios. It synergistically improves the dry matter digestibility and nitrogen utilization efficiency of cattle grazing in saline-alkali land, and the intestinal methane emission reduction effect is stable and controllable.

[0018] (2) Transforming traditional poisonous weeds into functional native grasses effectively alleviates the shortage of pasture resources in saline-alkali land, reduces breeding costs, and achieves efficient utilization of resources.

[0019] (3) The granular compound preparation prepared by the present invention is easy to store, transport and feed. The supplementary feeding program is designed to fit the breeding characteristics of cattle grazing in saline-alkali land. The supplementary feeding time, method and dosage have clear standards. It is easy to operate and does not require complicated equipment. It is suitable for large-scale promotion and application.

[0020] (4) This invention only collects the above-ground parts of Mongolian leek and Daphne odora, avoiding the roots and stems where the toxicity is relatively concentrated. Furthermore, the risk of toxicity accumulation is reduced through scientific proportion screening. As verified by experiments, cattle did not experience diarrhea, poisoning or other abnormal reactions after supplementation, and the feed intake rate was significantly improved, making it safe and reliable.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is an overall flowchart of the application method of a digestive and emission-reducing functional compound preparation for cattle grazing in saline-alkali land according to the present invention. Figure 2 This is a flowchart of the in vitro rumen fermentation ratio screening process for the application method of a digestive and emission-reducing functional compound preparation for cattle grazing in saline-alkali land, according to the present invention. Figure 3 This is a flow chart of the granular formulation preparation process for the application method of a digestive and emission-reducing functional compound preparation for cattle grazing in saline-alkali land according to the present invention. Figure 4 This is a bar chart comparing the in vitro DMD and CH4 emissions of functional native grasses with different mixing ratios of a functional compound preparation for digestion and emission reduction of cattle grazing in saline-alkali land, according to the present invention. Figure 5 This is a schematic diagram of the supplementary feeding implementation process and dosage calculation for the application method of a digestive and emission-reducing functional compound preparation for cattle grazing in saline-alkali land according to the present invention. Figure 6 This is a schematic diagram of the raw material collection and processing flow for the application method of a digestive and emission-reducing functional compound preparation for cattle grazing in saline-alkali land according to the present invention. Detailed Implementation

[0023] To make the technical solutions, advantages, and objectives of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the protection scope of this application.

[0024] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0025] like Figures 1-6 As shown, the present invention provides a method for applying a digestive and emission-reduction functional compound preparation for cattle grazing in saline-alkali land, comprising: S1. Select Mongolian leek and Daphne odora as raw materials to carry out in vitro rumen fermentation experiment. The experiment will obtain two core parameters: dry matter degradation rate and methane emission under different mixing ratios. The raw materials are collected only from the above-ground parts of Mongolian leek and Daphne odora, 15 days after the spring pasture turns green (when the plants are growing vigorously and the content of functional components is stable). After sorting and washing, the raw materials are dried at a constant temperature of 65℃ for 48 hours, pulverized using a pulverizer and passed through a 1mm sieve, and then sealed and stored in a cool, dry place for later use.

[0026] Nutritional composition test results of raw materials: Mongolian leek: 92.3% dry matter, 89.5% organic matter, 12.8% crude protein, 58.6% neutral detergent fiber, and 34.2% acid detergent fiber; Daphne odora: 91.7% dry matter, 88.9% organic matter, 10.5% crude protein, 62.3% neutral detergent fiber, and 38.7% acid detergent fiber.

[0027] In vitro rumen fermentation was constructed based on the Menke in vitro fermentation system, with the following specific conditions: Artificial rumen culture medium was prepared by mixing artificial culture medium with filtered fresh rumen fluid at a volume ratio of 1:2. The artificial culture medium was prepared by mixing the following components per 1 L volume: 237 mL of macro-element solution, 0.12 mL of trace element solution, 237 mL of buffer solution, 50 mL of reducing agent solution, and 1.22 mL of resazurin solution. After mixing, carbon dioxide was bubbled through the mixture until the solution became colorless. Healthy grazing cattle were selected from saline-alkali land. After fasting for 12 hours, rumen fluid was collected. Fresh rumen fluid was obtained by filtering through 4 layers of gauze. Fresh rumen fluid and artificial rumen culture medium were mixed and fermented at the above 1:2 volume ratio. Carbon dioxide was continuously introduced during fermentation to maintain an anaerobic environment. Fermentation temperature 39 The fermentation process was carried out at 0.5℃ for 24 hours. The material to be tested in the fermentation system was the substrate, which was a mixture of Mongolian leek and Daphne odora. The volume-to-mass ratio of the artificial rumen culture medium to the substrate was 40 mL: 1 g. The pH of the system was maintained at 6.5~7.2 during the fermentation process.

[0028] S2. Calculate the comprehensive score of different mixing ratios according to the formula, screen out the optimal mixing ratio, and prepare granular compound formulations according to this ratio. The optimal ratio is calculated and screened using the formula: ; In the formula, S is the comprehensive score; DMD is the dry matter degradation rate, %; CH4 is the methane emission, mL / gDM; the ratio corresponding to the maximum value of S is the optimal ratio. The optimal mixing ratio is Mongolian leek: Daphne odora = 7:3, which is the dry matter weight ratio after drying. This ratio satisfies S ≥ 0.35.

[0029] The preparation process of granular compound formulations includes: raw material drying, pulverization, mixing, granulation, and secondary drying.

[0030] According to the dry matter weight ratio of Mongolian leek to Daphne odora (7:3), weigh out Mongolian leek and Daphne odora, add 5% corn starch (5% of the total mass of Mongolian leek and Daphne odora) as a binder, and put them into a twin-shaft mixer and stir for 15 minutes until uniformly mixed to obtain a mixture. Feed the mixture into a ring die granulator, set the granulation pressure to 9 MPa and the aperture to 3 mm, and process it into cylindrical granules. Place the granules in a 65℃ oven for secondary drying, and then process them according to the formula... Test the moisture content until it is ≤10%. After cooling, screen for particles with uniform particle size and seal them for later use.

[0031] In the formula, m0 is the mass of the preparation before drying, in g; m1 is the mass of the preparation after drying, in g.

[0032] S3. Supplement the feed to cattle grazing on saline-alkali land with a fixed dose of compound preparation.

[0033] The fixed dosage of the compound preparation is calculated using the supplemental feeding dosage formula, which is: ; In the formula, M is the daily supplemental feed amount, g; k is the supplemental feed dosage coefficient, with a value range of 0.8~1.0 g / kgBW; BW is the weight of the grazing cattle, kg.

[0034] Supplementary feeding time is 19:00 daily. Supplemental feeding should be done separately for 30 minutes, followed by a 30-minute interval before providing drinking water.

[0035] The cattle grazed on saline-alkali land are Simmental cattle, and the grazing period is from the spring when the pasture turns green to the autumn when the pasture turns yellow.

[0036] The application method of the digestive and emission-reduction functional compound preparation for cattle grazing in saline-alkali land provided above is as follows: Example 1: A supplementary feeding verification experiment on Simmental cattle grazing in saline-alkali land from the spring greening period to the autumn withering period: Simmental cattle grazed on saline-alkali land were used as the test subjects. This area has poor forage quality, and the grazing cattle generally suffer from low dry matter digestibility and high methane emissions. Furthermore, Mongolian leek and Daphne odora are widely distributed naturally, fitting the application scenario of this invention. Healthy grazing cattle were selected, and the grazing period was from the spring greening stage to the autumn withering stage, suitable for verifying the effectiveness of the method of this invention. The specific implementation process is as follows: I. Experimental Materials and Equipment: Collect the above-ground parts of naturally growing Mongolian leek and Daphne odora (avoiding roots and stems to prevent toxicity accumulation), sort and remove impurities, and quickly rinse with clean water. The collection time is 15 days after the spring pasture turns green (when the plants are growing vigorously and the content of functional components is stable).

[0037] Raw material processing: The raw materials are dried at a constant temperature of 65℃ for 48 hours twice. After being crushed by a pulverizer, they are passed through a 1mm sieve and stored in a sealed, cool, and dry place for later use.

[0038] Nutritional composition test results of raw materials: Mongolian leek: 92.3% dry matter, 89.5% organic matter, 12.8% crude protein, 58.6% neutral detergent fiber, and 34.2% acid detergent fiber; Daphne odora: 91.7% dry matter, 88.9% organic matter, 10.5% crude protein, 62.3% neutral detergent fiber, and 38.7% acid detergent fiber.

[0039] Main equipment and reagents: Equipment: constant temperature water bath fermentation chamber, autoclave, electronic balance (accuracy 0.001g), pulverizer, ring die granulator (pore size 2~4mm), high performance liquid chromatograph, methane detector, crude fiber analyzer.

[0040] Reagents: Corn starch (binder), physiological saline (for diluting rumen fluid), and volatile fatty acid (VFA) standards.

[0041] II. Experimental Procedure: (1) Determining the optimal ratio: The optimal ratio is selected by setting multiple ratio gradients and quantifying key indicators. The specific steps are as follows: As shown in Table 1, based on functional balance requirements, five mixing ratios (dry matter weight ratio after drying) were designed for the preliminary experiments: 5:5, 6:4, 7:3, 8:2, and 9:1. The synergistic effect of "digestion-emission reduction" in each group was calculated using a comprehensive scoring formula derived from the dual-objective priority: ; Meaning of S value: The higher the S value, the better the synergistic effect of "digestion improvement" and "emission reduction". Table 1 Comparison of Gradient Results from Preliminary Experiments

[0042] The results showed that: 5:5 (high proportion of Daphne odora and Euphorbia fischeriana, high toxicity risk), 8:2 (high proportion of Allium mongolicum, weak emission reduction), and 9:1 (extremely weak emission reduction effect).

[0043] The 7:3 group had the highest S value (0.31) and simultaneously met the following criteria: DMD≥68% (significantly improved digestion), CH4≤110mL / gDM (emission reduction met), and no toxic reaction (Daphne odora accounted for 30%, and the toxicity of the above-ground parts was reduced after drying at 65℃).

[0044] (2) In vitro rumen fermentation detection: The in vitro rumen fermentation system was constructed by referencing the Menke in vitro fermentation system. The specific steps are as follows: Rumen fluid collection: Three healthy Simmental beef cattle weighing 250±20kg were selected from saline-alkali land. They fasted for 12 hours before the experiment. Fresh rumen fluid was collected through a rumen fluid collection tube and filtered through four layers of gauze to obtain rumen fluid. The rumen fluid was placed in a 39℃ thermos bottle and quickly brought back to the laboratory. Preparation of artificial culture medium: Prepare precisely according to 1L volume: 237mL macro-element solution, 0.12mL trace element solution, 237mL buffer solution, 1.22mL resazurin solution, and 50mL reducing agent solution. After mixing, purge with carbon dioxide until the solution changes from pink to colorless. Preheat to 39℃ for later use. Preparation of mixed fermentation broth: The filtered fresh rumen fluid and artificial culture medium were mixed at a volume ratio of 1:2 for fermentation. During fermentation, carbon dioxide was continuously introduced to maintain an anaerobic environment, and the mixture was kept at a constant temperature of 39°C with magnetic stirring for later use. Fermentation procedure: Accurately weigh 1.0g of the mixed raw materials (substrate) in each proportion using a 0.01g balance, and load it into a 37.4g container. A nylon bag (3.5cm × 2.5cm) with a pore size was sealed with 9g of glass beads to prevent floating. A 100mL Menke fermentation tube was then placed inside. 40mL of mixed fermentation broth (rumen fluid volume to substrate dry matter ratio of 40:1) was added to the fermentation tube. After removing all air, the tube was sealed and placed at 39°C. Ferment in a 0.5℃ constant temperature water bath fermentation box for 24 hours, gently shaking the fermentation tube once every 1 hour during the period; Index detection: After fermentation, the fermentation gas was collected and the methane concentration was determined by gas chromatography (weight 0.4); the dry matter degradation rate (DMD) of the nylon bags was determined after rinsing and drying (weight 0.6); the pH value of the fermentation broth was measured using a portable pH meter; and some samples were added with a protein-removing solution for the detection of volatile fatty acids.

[0045] Calculated using formula Based on the overall score, the S-value of the 7:3 ratio of Mongolian leek to Daphne odora was 0.38 (≥0.35), which was determined to be the optimal ratio.

[0046] (3) Preparation of granular compound formulations: Weigh out 7 kg of Mongolian leek powder and 3 kg of Daphne odora powder in a 7:3 ratio, add 500 g of corn starch (accounting for 5% of the total dry matter of the mixed Mongolian leek and Daphne odora), and put them into a twin-shaft mixer and stir for 15 minutes until they are evenly mixed.

[0047] Granulation: A ring die granulator is used, with a granulation pressure of 9MPa and a pore size of 2~4mm to produce cylindrical granules.

[0048] Secondary drying: Place the granules in a 65℃ oven to dry, take samples and weigh them every 2 hours, and test them using the moisture content formula until the moisture content drops to 9.5% (≤10%). After cooling, screen the granules with uniform particle size, seal and package them for later use.

[0049] Supplemental feeding trial: Experimental grouping: 20 beef cattle weighing 300-400 kg grazed on saline-alkali land were selected and randomly divided into a control group (no supplemental compound preparation) and an experimental group (supplemental compound preparation), with 10 cattle in each group. The pre-trial period was 7 days and the formal trial period was 60 days.

[0050] Both groups were allowed to graze freely on natural pasture in the same saline-alkali grazing area for 10 hours a day, and then entered the supplementary feeding area after returning to grazing. The experimental group was fed compound preparations according to the dosage, while the control group was only provided with drinking water. Feed intake was recorded. Rumen fluid samples were collected every 15 days during the trial period to determine the DMD and VFA content. Methane emissions were measured by the respiratory metabolism laboratory. The health status and weight changes of the cattle were recorded.

[0051] Supplemental feeding dosage: according to the formula Calculate, taking k=0.9g / kgBW, for example, a 300kg cow is supplemented with 270g per day, and a 400kg cow is supplemented with 360g per day.

[0052] Supplemental feeding method: Administer the compound preparation separately at 19:00 daily, and provide clean drinking water 30 minutes after feeding. Record the feeding situation.

[0053] III. Experimental Results and Analysis: Effects of supplemental feeding: The effect of supplemental feeding was compared between a control group (free access to natural saline-alkali pasture) and an experimental group (supplemented with compound feed) during a 60-day trial period (7-day pre-trial period). All data are expressed as mean ± standard deviation. Statistical analysis was performed using SPSS 26.0, and independent samples t-tests were used to determine differences between groups. P<0.05 This indicates a significant difference. P <0.01 indicates a highly significant difference. Specific quantitative data are as follows: To clearly distinguish between the in vitro screening ratio and the in vivo validation effect, the following breakdown is based on two main modules: in vitro screening and in vivo validation. (1) Optimal ratio effect of in vitro screening: In a laboratory setting simulating the rumen environment, preliminary screening was conducted to determine the proportion of grass species that could balance high digestibility and low methane emissions. All data came from Menke's in vitro rumen fermentation experiments, without the participation of live cattle. Specific data supporting the in vitro screening are shown in Table 1, and core data from the in vitro screening are shown in Table 2, which directly determined the proportion of grass species selected.

[0054] Table 2 Core data from in vitro screening

[0055] The pH value of the fermentation broth was maintained at 6.5~7.2 (the normal pH range of the rumen), proving that the in vitro environment simulation was effective. Total volatile fatty acids (VFA): Verifies the adequacy of substrate fermentation and indirectly corroborates the reliability of DMD data; Repeatability of parallel experiments: Each group was replicated 3 times, and the data were presented as mean values. The standard deviation is presented with an error of ≤5%, ensuring the reliability of the data.

[0056] (2) Validation of the optimal ratio effect in vivo: In a real-world saline-alkali land grazing scenario, the effectiveness of the proportions screened in vitro was verified. All data were obtained from a control supplementary feeding trial of 20 grazing beef cattle (control group vs. experimental group). The core data and results are shown in Table 3. Table 3 Core data and results of in vivo validation

[0057] All key indicators showed quantitative improvement with significant differences, fully verifying the effectiveness and reliability of the 7:3 ratio compound formulation in real grazing scenarios.

[0058] This embodiment uses in vitro rumen fermentation combined with quantitative formulas to screen the optimal mixing ratio of Mongolian leek and Daphne odora in a 7:3 ratio. The granular compound preparation prepared and fed to cattle in saline-alkali land at a fixed dose can synergistically improve the digestibility and nitrogen utilization efficiency of cattle grazing in saline-alkali land, significantly reduce methane emissions, realize the resource utilization of "toxic weeds", reduce breeding costs, and is simple to operate and suitable for large-scale promotion and application.

[0059] Example 2: Supplemental feeding trial of 6-month-old healthy male Simmental calves grazing in moderately saline-alkali land during winter: This embodiment is designed for winter grazing in moderately saline-alkali land. In winter, the forage in saline-alkali land is completely withered and yellow, with a crude fiber content exceeding 65%, resulting in extremely low nutritional value. Six-month-old Simmental calves have not yet fully developed their digestive systems and have weak tolerance to roughage, generally facing problems such as "winter weight loss," "sharply decreased digestibility," "relatively high methane emissions," and "vulnerable intestinal health." Healthy six-month-old male Simmental calves were selected as test subjects to verify the suitability and safety of the compound formulation of this invention in the "low-quality hay feeding period + juvenile stage," filling a gap in winter supplementary feeding technology for calves.

[0060] I. Experimental Materials and Equipment: Collect the above-ground parts of naturally growing Mongolian leek and Daphne odora (collect 10 days before they wither in autumn, when the functional components have accumulated sufficiently, and avoid the roots and stems to reduce the risk of toxicity). After sorting and removing impurities, rinse quickly with clean water, dry at a constant temperature of 65℃ for 48 hours, pulverize to 40 mesh (standard sieve passing rate ≥95%), seal and store in a cool and dry place for later use.

[0061] Nutritional composition of raw materials: Mongolian leek dry matter 93.0%, organic matter 90.1%, crude protein 11.8%, neutral detergent fiber 59.7%, acid detergent fiber 36.2%; Daphne odora dry matter 92.4%, organic matter 89.5%, crude protein 10.1%, neutral detergent fiber 63.8%, acid detergent fiber 39.8% (the crude protein content of raw materials in winter is slightly lower than that in spring, while the crude fiber content is slightly higher, which is consistent with the characteristics of winter forage in moderately saline-alkali land).

[0062] Equipment: constant temperature water bath fermentation chamber, autoclave, electronic balance (accuracy 0.001g), pulverizer, ring die granulator (orifice diameter 2~3mm, suitable for calf feed), high performance liquid chromatograph, methane detector, crude fiber analyzer.

[0063] Reagents: Corn starch (binder), physiological saline (for diluting rumen fluid), and volatile fatty acid (VFA) standards.

[0064] II. Experimental Procedure: (1) Optimal ratio verification: Using the core invention's established ratio of Mongolian leek: Daphne odora to Euphorbia fischeriana (7:3, dry matter weight ratio after drying), in vitro rumen fermentation verification was conducted to target the rumen microbial characteristics of calves. Three healthy 6-month-old Simmental calves (weighing 165 kg each) were selected. 15kg calves were fasted for 12 hours before rumen fluid was collected. An in vitro fermentation system specifically for calves was constructed. The test results showed that the S value was 0.35 (≥0.35), DMD=66.9%, CH4=109.2mL / gDM, which met the "digestion-emission reduction" synergistic standard. The pH value of the fermentation broth was stable at 6.7~6.9, which is suitable for the rumen environment of calves.

[0065] (2) Preparation of compound formulations: Weigh 14 kg of Mongolian leek powder and 6 kg of Daphne odora powder in a 7:3 ratio, add 1 kg of corn starch (5% of the total mass of the mixed raw materials), and mix in a twin-shaft mixer for 15 minutes until uniformly mixed. Use a ring die granulator, set the granulation pressure to 8 MPa (lower than the pressure of adult cattle preparations to avoid overly hard granules) and the aperture to 2.5 mm to produce fine cylindrical granules. Place the granules in a 65℃ oven for secondary drying, and test the moisture content using a formula until the moisture content drops to 9.3% (≤10%). After cooling, screen for granules with uniform particle size (to avoid overly large granules that would make it difficult for calves to eat), and seal them for later use.

[0066] (3) Supplemental feeding experiment design: Experimental grouping: 24 healthy male Simmental calves aged 6 months with an initial weight of 165 kg were selected. Calves weighing 15kg were randomly divided into a control group (no supplemental feed) and an experimental group (supplemental feed), with 12 calves in each group. The pre-trial period was 7 days (calves have strong adaptability, so the pre-trial period was shortened), and the formal trial period was 45 days (covering the severe winter period).

[0067] Feeding and management: Both groups were allowed to graze freely on withered yellow pasture and a small amount of alfalfa hay (as a routine supplementary feed for calves in winter) in moderately saline-alkali land. They were grazed for 6 hours a day (to avoid excessive energy consumption by calves) and then entered the supplementary feeding area after returning from grazing. The experimental group was supplemented with the prescribed dosage, while the control group was only provided with warm water.

[0068] Supplementary feed dosage: Calculate according to the supplementary feed dosage formula, taking k=0.85g / kgBW (calves have low digestive load, so a low dosage coefficient is selected). For example: 165kg calves are supplemented with 140.25g per day, and 180kg calves are supplemented with 153g per day.

[0069] Supplementary feed dosage formula: M=k×BW; where M is the daily supplementary feed amount, g; k is the supplementary feed dosage coefficient, with a value of 0.85g / kgBW; and BW is the calf's weight, kg.

[0070] Supplemental feeding method: 17:30 daily Feed separately for 30 minutes. When feeding, mix the pellet preparation with a small amount of alfalfa hay (to improve palatability). After feeding, provide warm water every 40 minutes (to prevent frostbite in winter and avoid cold water irritating the intestines).

[0071] III. Experimental Results and Analysis: Statistics on data from the 45-day trial period (average) Standard deviation), analyzed by SPSS 26.0, showed significant differences between groups ( P< 0.05 The in vitro validation data came from a calf-specific in vitro rumen fermentation experiment, and the in vivo data came from a real winter grazing and supplemental feeding experiment.

[0072] (a) Results of in vitro proportion verification: The suitability of the 7:3 ratio for low-quality feed in winter was verified through an in vitro rumen fermentation test specifically for calves. The key data are shown in Table 4. Table 4 Core Data for In Vitro Proportion Verification in Example 2

[0073] (2) Verification of the effect of in vivo supplementation: In a real winter grazing scenario, the practical application effect of the compound preparation on 6-month-old Simmental calves was verified. The core data and effects are shown in Table 5. Table 5 Core data and effects of in vivo supplementary feeding verification in Example 2

[0074] The compound formulation of this invention showed good in vitro compatibility with 6-month-old Simmental calves in winter grazing scenarios with moderately saline-alkali land. After in vivo supplementation, it significantly improved digestion, reduced methane emissions, and promoted weight gain. It can effectively solve the breeding problems caused by calves' low-quality pasture intake in winter. Moreover, the particle size and supplementation dosage are adapted to the characteristics of young cattle, and the safety is high.

[0075] Example 3: Supplemental feeding trial of 12-month-old healthy Simmental heifers grazing in severely saline-alkali land throughout their entire grazing period: This embodiment targets a full-cycle grazing scenario in severely saline-alkali land (spring greening period - summer growth period - autumn withering period, totaling 180 days). The biomass of forage in severely saline-alkali land is only 40% of that in mildly saline-alkali land, with crude protein content generally below 8% and crude fiber content ≥70%, representing an extremely harsh breeding environment. 12-month-old Simmental heifers are in a rapid growth phase with high nutritional requirements but limited tolerance to low-quality feed. Cattle at this stage were selected to verify the stability and sustained effectiveness of the formulation of this invention under long-term extreme conditions.

[0076] I. Experimental Materials and Equipment: The above-ground parts of Mongolian leek and Daphne odora are harvested in three seasons (15 days after the spring greening, during the summer flowering period, and 10 days before the autumn withering). After mixing, impurities are removed, the mixture is quickly rinsed with clean water, dried at a constant temperature of 65℃ for 48 hours, pulverized to 40 mesh, and sealed for storage (the mixed raw materials ensure a balanced functional composition to meet the nutritional needs of the entire life cycle).

[0077] Nutritional composition of raw materials: After mixing, the raw materials contain 92.7% dry matter, 89.2% organic matter, 11.2% crude protein, 61.2% neutral detergent fiber, and 37.6% acid detergent fiber.

[0078] Equipment: constant temperature water bath fermentation chamber, autoclave, electronic balance (accuracy 0.001g), pulverizer, ring die granulator (pore size 3~4mm), high performance liquid chromatograph, methane detector, crude fiber analyzer.

[0079] Reagents: Corn starch (binder), physiological saline (for diluting rumen fluid), and volatile fatty acid (VFA) standards.

[0080] II. Experimental Procedure: (1) Optimal ratio fit verification: For the mixed feedstock from severely saline-alkali land and the rumen characteristics of young cattle, compatibility verification was conducted using the core invention's in vitro fermentation detection method: Three healthy 12-month-old Simmental young cattle (weighing 280 kg each) were selected. Rumen fluid was collected from 20kg young cattle after fasting for 12 hours to construct an in vitro fermentation system. The test results showed that: DMD=68.3%, CH4=107.5mL / gDM, S value=0.36 (≥0.35), and the pH value of the fermentation broth was stable at 6.8~7.0, confirming that the 7:3 ratio was well adapted.

[0081] (2) Preparation of compound formulations: Weigh 21 kg of mixed raw material powder (spring + summer + autumn raw materials mixed) and 9 kg of Daphne odora powder in a 7:3 ratio, add 1.5 kg of corn starch (accounting for 5% of the total mass of the mixed raw materials), and put them into a twin-shaft mixer and stir for 15 minutes until they are evenly mixed; use a ring die granulator, set the granulation pressure to 9 MPa and the aperture to 3 mm, to make cylindrical granules; place the granules in a 65℃ oven for secondary drying, and test the moisture content using the moisture content formula until the moisture content drops to 9.7% (≤10%), cool, screen the granules with uniform particle size, and seal them for later use.

[0082] (3) Supplemental feeding experiment design: Experimental group: 30 healthy 12-month-old Simmental young cattle with an initial weight of 280 kg were selected. 20kg cattle were randomly divided into a control group (no supplemental compound preparation) and an experimental group (supplemental compound preparation), with 15 cattle in each group. The pre-trial period was 15 days (the adaptation period for young cattle is moderate), and the formal trial period was 180 days (covering the entire grazing cycle).

[0083] Feeding and management: Both groups were allowed to graze freely on natural pasture in severely saline-alkali land. The daily grazing time was adjusted according to the season (10 hours in spring, 8 hours in summer, and 12 hours in autumn, to adapt to the seasonal climate and pasture resources). After returning from grazing, they entered the supplementary feeding area. The experimental group was supplemented with feed according to the dosage, while the control group was only provided with clean drinking water.

[0084] Supplemental feed dosage: Adjust the k value according to the season and growth stage (k=0.85g / kgBW in spring, k=0.9g / kgBW in summer, and k=0.95g / kgBW in autumn). For example, a 280kg cow should be supplemented with 238g per day in spring, 252g in summer, and 266g in autumn; a 300kg cow should be supplemented with 255g per day in spring, 270g in summer, and 285g in autumn.

[0085] Supplementary feed dosage formula: M=k×BW; where M is the daily supplementary feed amount, g; k is the supplementary feed dosage coefficient; and BW is the weight of the young cattle, kg.

[0086] Supplemental feeding method: 19:00 daily Feed the individual every 30 minutes, and provide drinking water 30 minutes after feeding. In the summer when the temperature is high, cool the drinking water in advance, and provide warm water in the autumn when the temperature is low.

[0087] III. Experimental Results and Analysis: Statistics on data from the 180-day trial period (average) The standard deviation was analyzed using SPSS 26.0, and the differences between groups were highly significant ( ). P< 0.01 In vitro validation data came from a simulated fermentation experiment using a mixture of raw materials from severely saline-alkali land and rumen fluid from young cattle, while in vivo data came from a full-cycle real-world grazing and supplemental feeding experiment.

[0088] (1) Results of in vitro proportion fit verification: The long-term compatibility of the 7:3 ratio of raw materials in severely saline-alkali land was verified by in vitro rumen fermentation experiments. The key data are shown in Table 6. Table 6 Core Data for In Vitro Proportional Fit Verification in Example 3

[0089] (2) Verification of the effect of in vivo full-cycle supplementation: In a severely saline-alkali land grazing scenario, the long-term effects of the compound preparation on 12-month-old Simmental young cattle were verified. The core data and effects are shown in Table 7. Table 7 Core data and effects of in vivo full-cycle supplemental feeding verification in Example 3

[0090] The compound formulation of this invention has shown good in vitro compatibility with 12-month-old Simmental young cattle in the context of full-cycle grazing in severely saline-alkali land. Long-term in vivo supplementation can continuously improve digestive efficiency and nitrogen utilization, significantly reduce methane emissions, and meet the nutritional needs of young cattle during their rapid growth period. It has no risk of toxic accumulation and provides a stable and feasible solution for grazing and raising young cattle in extremely saline-alkali land.

[0091] Therefore, this invention provides a method for applying a functional compound preparation for digestion and emission reduction in cattle grazing in saline-alkali land. Mongolian leek and Daphne odora are selected as raw materials. An optimal mixing ratio of 7:3 is screened through in vitro rumen fermentation combined with a quantitative formula. Granular preparations are then prepared through drying, pulverizing, and granulation processes. These granules are then supplemented into feed for cattle grazing in saline-alkali land after they return to grazing, at a fixed dosage. This method solves the problems of low digestibility and high methane emissions in cattle grazing in saline-alkali land due to the consumption of low-quality forage. Furthermore, traditional toxic weeds such as Mongolian leek and Daphne odora are wasted, and the technical gap exists where single grass species cannot synergistically promote digestion and reduce methane emissions. This method improves the digestibility and nitrogen utilization efficiency of cattle grazing in saline-alkali land, simultaneously reducing methane emissions. It transforms "toxic weeds" into functional native grasses, expanding feed sources, reducing breeding costs, and is technically suitable for grazing scenarios. It is simple to operate and easy to scale up and apply.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for applying a digestion emission reduction functional composite preparation for grazing cattle in saline-alkali land, characterized in that, The application relates to a method for preparing a granular compound preparation for supplementing salt-alkali land grazing cattle. S1, selecting Mongolian leek and daphne as raw materials to carry out in-vitro rumen fermentation test, and obtaining two core parameters of dry matter degradation rate and methane emission amount under different mixing proportions through the test; S2, calculating the comprehensive score of different mixing proportions according to a formula, screening the optimal mixing proportion, and preparing the granular compound preparation according to the proportion, wherein the optimal proportion is screened through formula calculation, and the optimal proportion calculation formula is as follows: ； In the formula, S is the comprehensive score; DMD is the dry matter degradation rate, %; CH4 is the methane emission amount, mL / gDM; and the proportion corresponding to the maximum value of S is the optimal proportion; S3, supplementing the salt-alkali land grazing cattle with the compound preparation at a fixed dose.

2. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali land according to claim 1, characterized in that, In S1, the in-vitro rumen fermentation is based on the Menke in-vitro fermentation system, and the specific conditions are as follows: The artificial rumen culture solution is prepared by mixing artificial culture solution and filtered fresh rumen fluid at a volume ratio of 1:2; the artificial culture solution is prepared by mixing 237 mL of constant element solution, 0.12 mL of trace element solution, 237 mL of buffer solution, 50 mL of reducing agent solution and 1.22 mL of resazurin solution in 1 L of volume, and then carbon dioxide is introduced into the solution until the solution is colorless; Healthy grazing beef cattle in a salt-alkali land are selected, and the rumen fluid is collected after fasting for 12 hours; the fresh rumen fluid is obtained by filtering the rumen fluid through four layers of gauze, and the fresh rumen fluid is mixed with the artificial rumen culture solution at the above-mentioned volume ratio of 1:2 for fermentation; carbon dioxide is continuously introduced into the solution to maintain an anaerobic environment during the fermentation; Fermentation temperature 39 0.5°C, fermentation time 24 h, the material to be detected in the fermentation system was the substrate, the substrate was a mixture of Allium mongolicum and Stellera chamaejasme; the volume to mass ratio of the artificial rumen culture medium to the substrate was 40 mL: 1 g, and the pH value of the system was maintained at 6.5-7.2 during fermentation.

3. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali land according to claim 1, characterized in that, In S2, the optimal mixing proportion is the dry matter weight ratio of Mongolian leek to daphne after drying, which is 7:3, and the proportion meets S>=0.

35.

4. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali land according to claim 1, characterized in that, In S3, the fixed dose of the compound preparation is calculated through a supplementing dose formula, and the supplementing dose formula is as follows: ； In the formula, M is the daily supplementing amount, g; k is the supplementing dose coefficient, and the value range is 0.8-1.0 g / kgBW; and BW is the body weight of the grazing cattle, kg.

5. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali land according to claim 1, characterized in that, In S2, the preparation process of the granular compound preparation comprises the following steps: drying raw materials, crushing, mixing, granulating and secondary drying, wherein the crushing parameter is that the particle size of the crushed material is 40 meshes; and the moisture content after the secondary drying meets the formula: ； In the formula, m0 is the mass of the preparation before drying, g; and m1 is the mass of the preparation after drying, g.

6. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali soil according to claim 5, characterized in that, In S2, the drying conditions of the raw materials are constant temperature drying at 65 DEG C for 48 hours, and only the aboveground parts of Mongolian leek and daphne are collected as the raw materials.

7. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali soil according to claim 5, characterized in that, In S2, the granulating aperture is 2-4 mm, and the granulating pressure is 8-10 MPa.

8. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali land according to claim 1, characterized in that, In S3, the supplementing mode is separate feeding, and drinking water is provided after 30 minutes.

9. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali soil according to claim 1, characterized in that, The salt-alkali land grazing cattle are grazing beef cattle, and the grazing period is from the spring grass returning green period to the autumn grass withering period.

10. The method for applying the functional composite preparation for reducing digestion emissions for grazing cattle in saline-alkali land according to claim 1, characterized in that, In S2, a binder is additionally added in the mixing process, and the mass of the binder accounts for 5% of the total mass of the dry matter of the dried Mongolian leek and daphne; and the binder is corn starch.

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