A granular feed based on a combination of cotton by-products and a method for its preparation

Abstract

The application relates to the feed manufacturing field, and particularly discloses a granular feed ration based on a cotton byproduct combination and a preparation method thereof. The granular feed ration based on the cotton byproduct combination comprises cotton stalks, detoxified cottonseed meal, energy feed, mixed meal, a compound enzyme preparation, a gossypol detoxification synergist, a rumen-protected amino acid, a buffer, premix, salt, stone powder and calcium hydrogen phosphate. The cotton stalks are cotton straw subjected to silk rubbing treatment, and the silk rubbing length is 1-3 cm. The detoxified cottonseed meal is cottonseed meal subjected to microbial fermentation. The granular feed ration has the advantages of eliminating the toxicity risk of free gossypol in the cottonseed meal and significantly improving the palatability and digestibility of the cotton stalks.

Description

Technical Field

[0001] This application relates to the field of feed manufacturing, and more specifically, to a pelleted diet based on a combination of cotton by-products and a method for preparing the same. Background Technology

[0003] Despite the high potential of cottonseed meal and cotton stalks for feed applications, their practical application still faces numerous technical bottlenecks. Firstly, cottonseed meal contains anti-nutritional factors such as free gossypol, which is cytotoxic and reproductively toxic to animals. Long-term or excessive feeding can lead to growth inhibition and poisoning risks. Although rumen microorganisms in ruminants can partially degrade gossypol, its dosage must be strictly controlled when added in high proportions. Secondly, cotton stalks are hard, covered with a waxy layer, and have a high lignocellulose content, resulting in poor palatability, low feed intake, and difficulty in effective degradation by rumen microorganisms; the digestibility and utilization rate of direct feeding is less than 30%. Furthermore, the traditional method of separating concentrates and roughage feed suffers from nutritional imbalances, picky eating by sheep, and significant feed waste, failing to fully utilize the nutritional value of cotton by-products. While existing technologies report detoxification treatments for cottonseed meal or simple crushing of cotton stalks, these are mostly single-treatment methods, failing to achieve synergistic compatibility and industrial-scale full utilization of both.

[0004] To address the aforementioned issues, there is an urgent need in this field to develop a technical solution that can synergistically utilize cottonseed meal and cotton stalks. This solution should effectively reduce the toxicity risk of free gossypol, significantly improve the palatability and digestibility of cotton stalks, and, through scientific formulation design and processing technology, produce nutritionally balanced and easy-to-feed complete pelleted feed. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a pelleted diet based on a combination of cotton by-products and its preparation method.

[0006] The first part of this application provides a pelleted feed diet based on a combination of cotton by-products, which adopts the following technical solution: A pelleted diet based on a cotton by-product blend, comprising the following raw materials by dry matter weight percentage: Cotton stalks 30%–45%; 12%–20% of detoxified cottonseed meal; Energy feed 25%–35%; Mixed oilseed meals 5%–10%; Compound enzyme preparations: 0.1%–0.3%; Gossypol detoxification synergist: 0.3%–0.6%; Rumen-protected amino acids: 0.1%–0.3%; Buffer 0.5%–1.0%; Premixed feed 2.5%–3.5%; Salt content: 0.5%–0.8%; Stone powder 0.5%–1.5%; Calcium hydrogen phosphate 0.3%–1.0%; And the sum of the weight percentages of all components is 100%; The cotton stalks are cotton stalks that have been shredded, with a shred length of 1-3 cm; The detoxified cottonseed meal is cottonseed meal fermented by microorganisms.

[0007] By adopting the above technical solutions, cotton stalks, as a source of roughage, can have their palatability and physical properties improved after shredding. Controlling the shredding length to 1-3 cm ensures pellet formation while also facilitating rumen fermentation and rumen intake in ruminants. After microbial fermentation, the free gossypol content in detoxified cottonseed meal is significantly reduced, and protein bioavailability is improved, thus resolving the safety issues related to anti-nutritional factors in cottonseed meal. By compounding cotton stalks, detoxified cottonseed meal, energy feed, miscellaneous meals, and functional additives in specific proportions, a complete diet system based on cotton by-products is constructed. This significantly reduces dependence on conventional feed ingredients such as corn and soybean meal while ensuring nutritional balance, lowering feed costs by 20%-30% and achieving high-value conversion of cotton by-products and resource-saving aquaculture.

[0008] Optionally, the gossypol detoxification synergist comprises ferrous sulfate, vitamin C, and montmorillonite in a mass ratio of (5-10):(1-2):(3-5); the compound enzyme preparation is a mixture of cellulase, xylanase, phytase, and laccase, wherein the mass percentage of laccase is 5%-15%; the rumen-protected amino acid is pH-sensitive coated methionine and / or lysine; the buffer is a mixture of sodium bicarbonate and magnesium oxide in a mass ratio of 3-5:1; the premix contains vitamin A, vitamin D, vitamin E, and amino acid chelated trace elements iron, zinc, manganese, and copper, as well as inorganic iodine, selenium, and cobalt.

[0009] By adopting the above technical solution, the gossypol detoxification synergist uses a ternary composite system of ferrous sulfate, vitamin C, and montmorillonite. Ferrous sulfate complexes with free gossypol to form a poorly absorbed complex; vitamin C acts as an antioxidant to protect ferrous ions from oxidation; and montmorillonite further captures residual gossypol through interlayer adsorption. The three work synergistically to achieve a gossypol removal rate of over 95%. Laccase is introduced into the composite enzyme preparation, which can specifically degrade the phenolic structures in gossypol and lignin, working synergistically with cellulase, xylanase, and phytase. This product increases the degradation rate of neutral detergent fiber by 15%–20% and improves the utilization rate of phytic acid phosphorus; pH-sensitive coated amino acids have a release rate of ≤20% in the rumen and ≥80% in the small intestine, achieving precise rumen protection of amino acids; sodium bicarbonate and magnesium oxide are compounded in a 3–5:1 ratio, providing a long-lasting and stable buffering effect, effectively maintaining rumen pH under high concentrate feeding conditions; the bioavailability of amino acid chelated trace elements is 30%–50% higher than that of inorganic salts, comprehensively improving the nutritional value of the diet and animal production performance.

[0010] Optionally, the mass ratio of cotton stalks to detoxified cottonseed meal is (2.1 to 2.4):1, and the two together account for 54% to 58% of the total weight of the diet.

[0011] By adopting the above technical solution, when the mass ratio of cotton stalks to detoxified cottonseed meal is controlled at 2.1–2.4:1, and the two together account for 54%–58% of the total diet weight, the fiber structure and protein level of the diet reach an optimal balance: the effective neutral detergent fiber provided by cotton stalks can stimulate rumination and saliva secretion, maintaining rumen health; the degradable protein provided by detoxified cottonseed meal meets the nitrogen source requirements of rumen microorganisms, while the rumen-exposed protein portion supplements small intestinal amino acids. Within this ratio range, the dry matter digestibility, neutral detergent fiber degradation rate, and nitrogen deposition efficiency of the diet all reach optimal values, increasing daily weight gain by 8%–12% compared to the control group with deviations in the ratio, and reducing the feed conversion ratio to below 6.2:1, thus maximizing the utilization of the combined effect of cotton by-products.

[0012] Optionally, the cotton stalks may also be modified by the following methods: Soak cotton stalks in a 0.5%–2.0% sodium hydroxide solution at a solid-liquid ratio of 1:3–1:5 for 2–6 hours. After draining, place it in a microwave device and treat it at a microwave power of 500-1000W for 3-8 minutes; Wash with water until neutral, and dry until the moisture content is ≤12% to obtain modified cotton stalks.

[0013] By employing the above-mentioned technical solutions, dilute alkali solution treatment can disrupt the ester bonds between lignin and cellulose / hemicellulose, causing partial dissolution of lignin. Microwave treatment utilizes the high-frequency oscillation of polar molecules in a microwave field to generate thermal and non-thermal effects, making the cellulose crystalline region more porous and increasing its specific surface area. The synergistic effect of these two treatments reduces the lignin content of cotton stalks by 20%–35%, reduces cellulose crystallinity by 15%–25%, and significantly improves the accessibility of cellulase. The modified cotton stalks exhibit a 25%–35% higher degradation rate of neutral detergent fiber in the rumen compared to untreated cotton stalks, while also increasing the softening of the material and further improving pellet formation and palatability, providing technical support for the widespread application of high-proportion cotton stalk diets.

[0014] Optionally, the method for preparing the detoxified cottonseed meal includes the following steps: Adjust the moisture content of cottonseed meal to 40%–50%, and inoculate it with Bacillus subtilis and Saccharomyces cerevisiae at inoculation rates of 1%–3% and 0.5%–1.5%, respectively. Solid-state fermentation at 28–37°C for 48–72 hours; Dry until the moisture content is ≤10%, then crush and sieve to obtain detoxified cottonseed meal.

[0015] By employing the above-mentioned technical solution, Bacillus subtilis secretes cellulase and protease, which can partially degrade the fibrous material and protein in cottonseed meal, exposing bound gossypol. Saccharomyces cerevisiae adsorbs and degrades free gossypol through metabolic activity, simultaneously producing microbial protein and beneficial metabolites. After 48–72 hours of synergistic fermentation by the two strains, the free gossypol content can be reduced to below 200 mg / kg, with a removal rate exceeding 85%, while protein solubility remains above 75%, and small peptide content increases. The organic acids, vitamins, and unknown growth factors produced during fermentation can improve the palatability and intestinal health of the diet. Compared to untreated cottonseed meal or cottonseed meal fermented with a single strain, the daily weight gain and feed conversion ratio of fed animals are significantly improved.

[0016] Secondly, this application provides a method for a pelleted feed diet based on a combination of cotton by-products, comprising the following steps: Weigh out all raw materials except the compound enzyme preparation according to the formula, mix them evenly to obtain a mixture; The mixture is conditioned by steam at a temperature of 85–90°C for 5–8 minutes. After conditioning, the moisture content of the mixture is 16%–18%. The conditioned mixture is pressed into granules at a granulation temperature of 85–95℃ and a granule diameter of 6–8 mm. After cooling the granules to room temperature, the compound enzyme preparation was formulated into a liquid and sprayed onto the surface of the cooled granules, and then dried until the moisture content was ≤12.5%.

[0017] By adopting the above technical solution, the conditioning step is carried out at 85-90℃ and 16%-18% moisture content, which fully gelatinizes the starch and softens the fiber, while using high temperature to initially reduce the toxicity of free gossypol. The pelleting process is carried out at 85-95℃ and a compression ratio of 1:8-1:10, giving the pellets good physical qualities. After cooling, the compound enzyme preparation is sprayed onto the surface of the pellets in liquid form, avoiding the denaturation and inactivation of enzyme proteins at high temperatures, and resulting in higher retention rates of cellulase, xylanase, phytase, and laccase. This process ensures both the storage and transportation performance of the pelleted feed and the effective functioning of the functional enzyme preparation in the animal body.

[0018] Optionally, the compression ratio of the mixture into granules in the granulation step is 1:8 to 1:10.

[0019] By adopting the above technical solution, when the compression ratio is too low (<1:8), the granules are loose and brittle, with a high pulverization rate and significant losses during transportation and storage; when the compression ratio is too high (>1:10), the resistance of the material passing through the die orifice is too great, the granulation temperature may rise and some heat-sensitive components may be lost, and energy consumption will increase. Controlling the compression ratio within the range of 1:8 to 1:10 allows materials containing 30% to 45% cotton stalks to be successfully shaped, with granule hardness controlled at 80 to 120 N and a durability index ≥95%. This ensures the physical quality of the granules while avoiding the increased energy consumption and component loss caused by excessive compression, achieving a balance between granulation efficiency and product quality.

[0020] Optionally, the solid content of the compound enzyme preparation when formulated into a spraying liquid is 5% to 15%, the atomization pressure during spraying is 0.2 to 0.4 MPa, and the temperature of the spraying liquid is 25 to 35°C.

[0021] By adopting the above technical solution, the solid content of the spray liquid is controlled at 5% to 15%, which ensures the amount of enzyme preparation deposited on the surface of each unit mass of particles and avoids uneven spraying caused by excessive concentration. The atomization pressure of 0.2 to 0.4 MPa enables the spray liquid to form droplets of suitable particle size, which uniformly cover the particle surface, and the penetration depth is controlled at 0.5 to 1.5 mm on the particle surface. The temperature of the spray liquid is 25 to 35℃, which is close to the optimal storage temperature of the enzyme preparation, avoiding the impact of excessively high or low temperatures on enzyme activity.

[0022] In summary, this application has the following beneficial effects: 1. This application uses cotton stalks and detoxified cottonseed meal as core raw materials. Through spun cotton and detoxification pretreatment, it solves the problems of poor palatability and the presence of anti-nutritional factors in cotton by-products, and achieves low-cost resource utilization.

[0023] 2. This application prioritizes the synergistic combination of multiple functional additives, including compound detoxifiers, compound enzyme preparations containing laccase, rumen-protected amino acids, and buffers, to comprehensively improve the safety, digestibility, and nutritional balance of the diet.

[0024] 3. The method of this application adopts high-temperature granulation and post-coating process, which not only ensures the physical quality of the particles, but also avoids the inactivation of heat-sensitive enzymes, thereby achieving effective retention of functional components and stable product production. Detailed Implementation

[0025] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources. Example

[0026] Example 1 This example provides a pelleted feed diet based on a combination of cotton by-products. The specific raw material ratio, specifications and preparation method are as follows, based on a total of 10 kg.

[0027] I. Raw material ratio and specifications Weigh each raw material according to the following dry matter weight: 3800g of cotton stalks, made from cotton stalks produced in Xinjiang, which are naturally dried after harvesting, processed by a sifting machine to a length of 1-3cm (average about 2cm), impurities removed, and moisture content ≤12%; 1600g of detoxified cottonseed meal was prepared as follows in this embodiment: 10kg of cottonseed meal, a byproduct of pre-pressing and extraction of cottonseed from Xinjiang, was weighed, with a crude protein content ≥40%, free gossypol content ≤1200mg / kg, and moisture content ≤12%. 160g of ferrous sulfate (FeSO4·7H2O), industrial grade, purity ≥98%, was weighed and used as a detoxifying agent. 160g of ferrous sulfate was dissolved in 8kg of water at a temperature controlled at 30-40℃, and stirred until completely dissolved to prepare a 2% ferrous sulfate solution. 10kg of cottonseed meal was added to a mixing container, and the above ferrous sulfate solution was added. The mixture was stirred thoroughly to ensure uniform mixing of the cottonseed meal and solution, controlling the material-to-liquid ratio to 1:0.8. Stirring was continued for 5 minutes to ensure the cottonseed meal was fully soaked. After soaking, cottonseed meal was left to stand at room temperature for 2 hours, turning it over every 30 minutes to ensure sufficient contact between ferrous sulfate and free gossypol in the cottonseed meal, resulting in a complexation reaction that forms a gossypol-iron complex that is not easily absorbed by animals. The cottonseed meal, after standing and reacting, was then spread on a drying tray, no more than 3 cm thick, and placed in a drying device for drying. The drying temperature was controlled at 60–70℃, and the drying time was 3 hours, with occasional turning to ensure even evaporation of moisture. The material was dried until the moisture content was ≤10%. The dried cottonseed meal was then fed into a pulverizer and pulverized until all of it passed through a 2.5 mm sieve, yielding the detoxified cottonseed meal product. 3000g of corn, from Northeast China, ground through a 2.5mm sieve, moisture content ≤13%; 700g of safflower seed meal, produced in Xinjiang, with a crude protein content ≥34%, ground through a 2.5mm sieve, and a moisture content ≤12%; The compound enzyme preparation (20g) is composed of cellulase (enzyme activity ≥10000U / g), xylanase (enzyme activity ≥5000U / g), phytase (enzyme activity ≥5000U / g), and laccase (enzyme activity ≥3000U / g) in a mass ratio of 45:25:20:10, with laccase accounting for 10% of the mass. Gossypol detoxification synergist 45g is a compound of ferrous sulfate (FeSO4·7H2O, industrial grade, purity ≥98%), vitamin C (food grade, purity ≥99%) and montmorillonite (feed grade, purity ≥95%) in a mass ratio of 8:1.5:4. 20g of rumen-protected methionine is a pH-sensitive coated methionine with a rumen release rate ≤20%, a small intestinal release rate ≥85%, and a methionine content ≥70%. 75g of buffer is a mixture of sodium bicarbonate (feed grade, purity ≥99%) and magnesium oxide (feed grade, purity ≥98%) in a mass ratio of 4:1. 300g of premix is ​​a compound premix for meat sheep. Each kilogram contains: Vitamin A 900KIU, Vitamin D 300KIU, Vitamin E 3500IU, amino acid chelated iron 9000mg, amino acid chelated zinc 7500mg, amino acid chelated manganese 4500mg, amino acid chelated copper 1200mg, iodine (calcium iodate) 90mg, selenium (sodium selenite) 55mg, cobalt (cobalt sulfate) 75mg, and the carrier is zeolite powder. 60g of table salt, feed grade, particle size ≤0.5mm; 120g of stone powder, feed grade stone powder, calcium content ≥38%, pulverized through a 0.45mm sieve; 60g of dicalcium phosphate, feed grade dicalcium phosphate, phosphorus content ≥16%, calcium content ≥21%.

[0028] II. Preparation Method (1) Cotton stalk spinning pretreatment Air-dried cotton stalks are fed into a sifting machine. The sifting gap is adjusted so that the length of the stalks after sifting is 1-3cm (mainly 2cm). Uncrushed long stalks and impurities are removed and set aside. The purpose of sifting is to break down the waxy layer on the surface of the cotton stalks, increase the specific surface area, facilitate the penetration of moisture and heat during subsequent conditioning, and improve pellet formation.

[0029] (2) Ingredient preparation and primary mixing Weigh out the following ingredients: detoxified cottonseed meal, corn, safflower seed meal, gossypol detoxification enhancer, buffer, premix, salt, limestone powder, and dicalcium phosphate. Add the above dry ingredients to a twin-shaft paddle mixer and mix for 8 minutes to ensure thorough mixing of all components, with a coefficient of variation ≤5%. This step of mixing the ingredients other than cotton stalks first ensures even distribution of trace elements and functional additives in the diet and avoids the large volume of cotton stalks affecting the mixing effect.

[0030] (3) Secondary mixing Add 3800g of shredded cotton stalks to the mixer and continue mixing for 4 minutes to ensure the cotton stalks are fully coated with the powdered material, thus obtaining the mixture. The second mixing time should not be too long to avoid excessive pulverization of the cotton stalks, which would affect the shredding effect.

[0031] (4) Conditioning The mixture is fed into the conditioner via a screw conveyor, while saturated steam is introduced for conditioning. The conditioning temperature is controlled at 88℃ (allowable fluctuation ±2℃), and the conditioning time is 6 minutes. The moisture content of the conditioned material is 17% (allowable fluctuation ±0.5%). During the conditioning process, starch gelatinizes, proteins denature, and fibers soften. High temperature further reduces the toxicity of free gossypol. The conditioned material should be loose, without lumps, and should be able to be formed into a ball by hand but crumble easily upon light pressure.

[0032] (5) Granulation The conditioned material is fed into a ring die pellet mill for pelleting. The pelleting temperature is controlled at 90℃ (with an allowable fluctuation of ±3℃), the ring die compression ratio is 1:9, and the pellet diameter is 8mm. During pelleting, the material passes through the die holes under high pressure, forming dense pellets, which further improves the softening of fibers and the gelatinization of starch. The resulting pellets should have a smooth surface, neat cuts, and no obvious cracks.

[0033] (6) Cooling The resulting hot granules are fed into a counter-current cooler and cooled until the particle temperature is no more than 5°C above room temperature (i.e., ≤30°C). The cooling airflow rate and residence time must be appropriately controlled to allow the particles to cool slowly and prevent surface cracking. After cooling, the particle moisture content is reduced to 13%–14%.

[0034] (7) Preparation of post-spraying liquid Dissolve 20g of the compound enzyme preparation and 20g of rumen-protected methionine in an appropriate amount of water to prepare a spraying solution with a total weight of 200g, controlling the solid content to 10%. When adding the solution, control the water temperature at 30℃ (allowing fluctuations of ±2℃), and stir slowly to ensure the enzyme preparation and methionine are fully dissolved or dispersed, avoiding the formation of bubbles. The spraying solution should be prepared immediately before use and stored for no more than 2 hours.

[0035] (8) Post-coating The cooled granules are fed into the post-coating equipment, where the coating liquid is evenly sprayed onto the granule surface under an atomization pressure of 0.3 MPa. During the spraying process, the granules should be in a tumbling state to ensure uniform coating. The amount of coating liquid used is 20 kg per ton of granulated feed (i.e., 2%), which is 200 g of coating liquid per 10 kg of granules.

[0036] (9) Drying and Packaging The coated granules are further dried in a fluidized bed dryer, with the hot air temperature controlled at 40-45℃, until the moisture content of the granules is ≤12%. The dried granules are then sieved by a vibrating screen to remove powder and broken particles, and then metered and packaged to obtain the finished pelleted feed ration.

[0037] Example 2: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that, based on a total weight of 10 kg, the amounts of each raw material are as follows: 3810 g cotton stalks, 1694 g detoxified cottonseed meal, 2964 g corn, 847 g miscellaneous meal, 25 g compound enzyme preparation, 51 g gossypol detoxification synergist, 25 g rumen-protected amino acids, 85 g buffer, 296 g premix, 51 g salt, 102 g limestone powder, and 51 g dicalcium phosphate. The rest are the same as in Example 1.

[0038] Example 3: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that, based on a total weight of 10 kg, the amounts of each raw material are as follows: 3000 g cotton stalks, 1200 g detoxified cottonseed meal, 3854 g corn, 500 g miscellaneous meal, 10 g compound enzyme preparation, 30 g gossypol detoxification synergist, 10 g rumen-protected amino acids, 50 g buffer, 250 g premix, 60 g salt, 120 g limestone powder, 60 g dicalcium phosphate, and the rest are the same as in Example 1.

[0039] Example 4: A method for preparing a pelleted feed diet based on a combination of cotton by-products: The difference from Example 1 is that the gossypol detoxifying synergist is a compound of ferrous sulfate, vitamin C, and montmorillonite in a mass ratio of 5:2:5. The rest is the same as in Example 1.

[0040] Example 5: A method for preparing a pelleted feed diet based on a combination of cotton by-products: The difference from Example 1 is that the gossypol detoxifying synergist is a compound of ferrous sulfate, vitamin C, and montmorillonite in a mass ratio of 10:1:3. The rest is the same as in Example 1.

[0041] Example 6: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that 20g of a compound enzyme preparation is made by mixing cellulase (enzyme activity ≥10000U / g), xylanase (enzyme activity ≥5000U / g), phytase (enzyme activity ≥5000U / g), and laccase (enzyme activity ≥3000U / g) in a mass ratio of 50:25:20:5, with laccase accounting for 5% of the total mass. The rest is the same as in Example 1.

[0042] Example 7: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that 20g of a compound enzyme preparation is prepared by mixing cellulase (enzyme activity ≥10000U / g), xylanase (enzyme activity ≥5000U / g), phytase (enzyme activity ≥5000U / g), and laccase (enzyme activity ≥3000U / g) in a mass ratio of 40:22:18:20, wherein laccase accounts for 14% of the total mass. The rest is the same as in Example 1.

[0043] Example 8: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that 20g of rumen-protected lysine is pH-sensitive coated lysine.

[0044] Example 9: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that 20g of rumen-protected amino acids are prepared by mixing rumen-protected methionine and rumen-protected lysine in a mass ratio of 1:1.

[0045] Example 10: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the buffer is a mixture of sodium bicarbonate and magnesium oxide in a mass ratio of 3:1.

[0046] Example 11: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the buffer is a mixture of sodium bicarbonate and magnesium oxide in a mass ratio of 5:1.

[0047] Example 12: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the mass ratio of cotton stalks to detoxified cottonseed meal is adjusted to 2.4:1, and the two together account for 58% of the total weight of the diet.

[0048] Example 13: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the mass ratio of cotton stalks to detoxified cottonseed meal is adjusted to 2.1:1, and the two together account for 54% of the total weight of the diet.

[0049] Example 14: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the cotton stalks are further modified by the following method: Weigh 5 kg of cotton stalks, which are cotton stalks produced in Xinjiang. After harvesting, they are naturally dried and processed by a sifting machine to a length of 2-3 cm. Impurities are removed and the moisture content is ≤12%.

[0050] Weigh 50g of sodium hydroxide (industrial grade, purity ≥98%), dissolve it in 5L of water, and stir until completely dissolved to prepare a 1.0% sodium hydroxide solution. Based on a solid-liquid ratio of 1:4, this solution is sufficient to soak 5kg of cotton stalks.

[0051] Add 5 kg of shredded cotton stalks to a soaking tank or corrosion-resistant container, and add 20 L of the aforementioned 1.0% sodium hydroxide solution, ensuring the cotton stalks are completely submerged. Soak at room temperature for 4 hours, stirring every hour to ensure thorough contact between the cotton stalks and the alkaline solution. The purpose of alkaline soaking is to break down the ester bonds between lignin and cellulose / hemicellulose in the cotton stalks, causing some lignin to dissolve and reducing the crystallinity of the fiber.

[0052] After soaking, remove the cotton stalks and place them on a draining sieve to drain naturally for about 30 minutes, or until there are no obvious drips on the surface of the cotton stalks and no water can be squeezed out by hand. The moisture content of the drained cotton stalks is about 65% to 75%.

[0053] Spread the drained cotton stalks evenly on the microwave equipment tray, with a thickness of 3-5 cm. Place the tray into the microwave equipment, set the microwave power to 800W, and the processing time to 5 minutes. During microwave treatment, the polar molecules in the cotton stalks generate high-frequency oscillations in the microwave field, producing thermal and non-thermal effects. This loosens the structure of the cellulose crystal zone, increases the specific surface area, and further disrupts the dense structure of the fiber. Carefully observe the condition of the cotton stalks during the treatment to prevent localized overheating and carbonization.

[0054] After microwave treatment, remove the cotton stalks and rinse them repeatedly in a clean water tank. Each rinse should use enough water to completely submerge the stalks. Rinse 3-5 times until the wash water is neutral (pH 6.5-7.5) according to pH test paper. The purpose of rinsing is to remove residual alkali and dissolved lignin degradation products.

[0055] After washing, place the cotton stalks in a dehydrator to remove excess surface moisture. Then, spread the cotton stalks on a drying tray, with a thickness not exceeding 5 cm, and send them into a drying device for drying. Control the drying temperature at 70-80℃ and the drying time at approximately 4-6 hours, turning them occasionally to ensure even evaporation of moisture. Dry until the moisture content of the cotton stalks is ≤12%.

[0056] Example 15: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 14 is that cotton stalks are soaked in a 0.5% sodium hydroxide solution at a solid-liquid ratio of 1:3 for 2 hours. After draining, place it in a microwave device and process it at a microwave power of 500W for 3 minutes; Wash with water until neutral, and dry until the moisture content is ≤12% to obtain modified cotton stalks.

[0057] Example 16: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 14 is that cotton stalks are soaked in a 2.0% sodium hydroxide solution with a solid-liquid ratio of 1:5 for 6 hours. After draining, place it in a microwave device and process it at a microwave power of 1000W for 8 minutes; Wash with water until neutral, and dry until the moisture content is ≤12% to obtain modified cotton stalks.

[0058] Example 17: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the method for preparing detoxified cottonseed meal includes the following steps: Weigh 10 kg of cottonseed meal, a byproduct of pre-pressing and extraction of cottonseed from Xinjiang, with a crude protein content ≥40%, free gossypol content ≤1200 mg / kg, and moisture content ≤12%. Crush the cottonseed meal until it passes completely through a 2.0 mm sieve and set aside.

[0059] The selected strains were Bacillus subtilis (CGMCC No. 1.1086) and Saccharomyces cerevisiae (CGMCC No. 2.1688), both commonly used strains in the feed industry.

[0060] Bacillus subtilis was inoculated onto nutrient agar slants and incubated at 37°C for 24 hours; Saccharomyces cerevisiae was inoculated onto malt extract agar slants and incubated at 30°C for 48 hours to activate the bacterial strains. The activated Bacillus subtilis slants were washed with sterile physiological saline to remove the bacterial growth, and then inoculated into 500 mL of nutrient broth medium. The culture was incubated at 37°C with shaking at 180 rpm for 24 hours to obtain a Bacillus subtilis seed culture with a colony count ≥1×10⁻⁶. 9 CFU / mL. Take the activated *Saccharomyces cerevisiae* slant, wash off the bacterial colony with sterile physiological saline, and inoculate it into 500 mL of malt extract liquid medium. Incubate at 30℃ and 150 rpm for 36 hours with shaking to obtain *Saccharomyces cerevisiae* seed culture with a colony count ≥1×10⁻⁶. 8 CFU / mL.

[0061] Add 10 kg of cottonseed meal to a mixer, and while stirring, add an appropriate amount of sterile water to adjust the moisture content of the cottonseed meal to 45%. Add water in several batches during the adjustment process, mixing for 3 minutes after each addition to ensure even moisture distribution. The final product should be able to clump together when squeezed but crumble easily when lightly touched. Based on the dry weight of the cottonseed meal, take 200 mL of activated Bacillus subtilis seed solution (corresponding to 2% inoculum) and 100 mL of Saccharomyces cerevisiae seed solution (corresponding to 1% inoculum) and spray them evenly onto the surface of the moistened cottonseed meal. Continue mixing for 10 minutes to ensure the bacterial solutions and material are thoroughly mixed and evenly distributed.

[0062] Spread the inoculated cottonseed meal material in fermentation trays to a thickness of 5-8 cm, with each tray containing approximately 2 kg of material. Place the trays in a constant-temperature fermentation chamber, maintaining a fermentation temperature of 32℃ for 60 hours. During fermentation, stir the material every 12 hours to facilitate heat dissipation and oxygen exchange, preventing localized overheating. During fermentation, Bacillus subtilis secretes cellulase and protease, which partially degrade the fibrous material and protein in the cottonseed meal, exposing bound gossypol. Saccharomyces cerevisiae adsorbs and degrades free gossypol through metabolic activity, simultaneously producing cell proteins and beneficial metabolites such as organic acids, vitamins, and unknown growth factors.

[0063] After fermentation, remove the fermented material and spread it on a drying tray, no more than 3 cm thick, and place it in a drying device. The drying temperature should be controlled at 60–65℃, and the drying time approximately 8–10 hours. During this time, turn the material occasionally to ensure even evaporation of moisture. Dry until the moisture content of the material is ≤10%. The drying temperature should not be too high to avoid destroying the heat-sensitive beneficial components produced during fermentation.

[0064] The dried fermented material is fed into a pulverizer and pulverized until it all passes through a 2.5mm sieve. The pulverized detoxified cottonseed meal is a yellowish-brown powder with a strong fermented aroma and no off-odors. After passing inspection, it is sealed and packaged to obtain the finished detoxified cottonseed meal.

[0065] Example 18: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 17 is that Bacillus subtilis and Saccharomyces cerevisiae are inoculated at 1% and 1.5% of the amount, respectively.

[0066] Example 19: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 17 is that Bacillus subtilis and Saccharomyces cerevisiae are inoculated at 3% and 0.5% of the amount, respectively.

[0067] Example 20: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the compression ratio of the mixed materials to pellets in the pelleting step is 1:8.

[0068] Example 21: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the compression ratio of the mixed materials to pellets in the pelleting step is 1:10.

[0069] Example 22: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the solid content of the compound enzyme preparation when it is formulated into a spraying liquid is 5%.

[0070] Example 23: A method for preparing a pelleted diet based on a combination of cotton by-products: The difference from Example 1 is that the solid content of the compound enzyme preparation when it is formulated into a spraying liquid is 15%.

[0071] Comparative Example 1 The difference between this comparative example and Example 1 is that the cotton stalks were not shredded and were directly crushed to a length of 2-3 cm before use; the cotton meal was not detoxified and was directly used as untreated ordinary cotton meal (free gossypol content ≤1200mg / kg); the other raw materials and preparation methods were the same as in Example 1.

[0072] Comparative Example 2 The difference between this comparative example and Example 1 is that no compound enzyme preparation is added, that is, the amount of compound enzyme preparation used is 0, and the other raw materials and preparation methods are the same as in Example 1.

[0073] Comparative Example 3 The difference between this comparative example and Example 1 is that no gossypol detoxification synergist is added, that is, the amount of gossypol detoxification synergist is 0, and the other raw materials and preparation methods are the same as in Example 1.

[0074] Comparative Example 4 The difference between this comparative example and Example 1 is that the rumen-protected methionine is replaced with an equal amount of ordinary methionine (uncoated), while the other raw materials and preparation methods are the same as in Example 1.

[0075] Comparative Example 5 The difference between this comparative example and Example 1 is that the buffer is a single sodium bicarbonate, used in an amount of 75g, and no magnesium oxide is added. The other raw materials and preparation methods are the same as in Example 1.

[0076] Comparative Example 6 The difference between this comparative example and Example 1 is that the compound enzyme preparation is made by mixing cellulase, xylanase and phytase in a mass ratio of 45:25:20, without laccase, and the total amount used is 20g. The other raw materials and preparation methods are the same as in Example 1.

[0077] Comparative Example 7 The difference between this comparative example and Example 1 is that all raw materials (including cotton stalks) are put into the mixer at once and mixed for 12 minutes without secondary mixing. The remaining raw materials and preparation methods are the same as in Example 1.

[0078] Comparative Example 8 The difference between this comparative example and Example 1 is that the compound enzyme preparation and rumen-protected methionine are added together with the dry raw materials before conditioning, and no post-coating is performed. The other raw materials and preparation methods are the same as in Example 1.

[0079] I. Methods for Testing Physicochemical Indicators 1. Determination of free gossypol content Refer to GB / T 13086-2020 "Determination of Free Gossypol in Feed". Take 10g of sample, extract with 70% acetone aqueous solution by shaking, filter, take the filtrate, add aniline and glacial acetic acid, react in a 60℃ water bath for 30 minutes, cool, and measure the absorbance at 550nm wavelength. Calculate the free gossypol content (mg / kg) using a standard curve.

[0080] 2. Determination of enzyme activity retention rate in compound enzyme preparations (1) Cellulase activity: Refer to GB / T 23881-2009 "Determination of cellulase activity for feed - filter paper method". Using filter paper as substrate, react for 1 hour at 40℃ and pH 4.8. The amount of reducing sugar generated is determined by the DNS method, and the enzyme activity (U / g) is calculated. Enzyme activity retention rate (%) = (enzyme activity in finished pellets / enzyme activity before spraying) × 100%.

[0081] (2) Xylanase activity: Refer to GB / T 23874-2009 "Determination of Xylanase Activity in Feed Additives - Spectrophotometric Method". Using oat xylan as a substrate, the reaction was carried out at 37℃ and pH 5.5 for 30 minutes, and the amount of reducing sugar produced was determined by the DNS method.

[0082] (3) Phytase activity: Refer to GB / T 18634-2009 "Determination of phytase in feed - spectrophotometric method". Sodium phytate was used as substrate, and the reaction was carried out at 37℃ and pH 5.5 for 30 minutes. Ammonium vanadate was used for color development, and the absorbance was measured at a wavelength of 415 nm.

[0083] (4) Laccase activity: Refer to the industry standard "Determination of Laccase Activity in Feed Additives - Spectrophotometric Method". Using ABTS as substrate, react for 3 minutes at 30℃ and pH 4.5, and measure the change in absorbance at a wavelength of 420nm.

[0084] After all the above tests are completed, calculate the total enzyme activity retention rate. Enzyme activity retention rate (%) = (Enzyme activity in finished particles / Theoretical enzyme activity in the compound enzyme preparation before spraying) × 100% in: Enzyme activity in finished granules: Take finished granules before final packaging and determine the activities (U / g granules) of cellulase, xylanase, phytase and laccase according to the methods described above.

[0085] Theoretical enzyme activity in the compound enzyme preparation before spraying: calculated based on the ratio of the compound enzyme preparation and the original enzyme activity of each enzyme component, that is, theoretical enzyme activity before spraying = enzyme activity contribution value of each enzyme component in the compound enzyme preparation (U / g particles).

[0086] 3. Particle Durability Index (PDI) Determination Refer to Appendix A of GB / T 16765-2008 "General Technical Specifications for Pelleted Feed". Take 500g of cooled pellets and place them in a pellet durability tester. Rotate the pellets at 50r / min for 10 minutes. Remove the pellets and pass them through a sieve with specified mesh size. Weigh the material remaining on the sieve. PDI (%) = (weight of material remaining on the sieve / weight of the sample) × 100%.

[0087] 4. Powdering rate determination Refer to GB / T 16765-2008. Take 500g of granular material, place it in a pulverization tester, rotate it at 50r / min for 5 minutes, remove it, pass it through a 2.0mm sieve, and weigh the material passing through the sieve. Pulverization rate (%) = (weight of material passing through the sieve / weight of the sample) × 100%.

[0088] 5. Moisture content determination Refer to GB / T 6435-2014 "Determination of Moisture in Feed". Take 2-5g of sample, place it in a constant temperature drying oven at 105℃ and dry it to constant weight, then calculate the moisture content (%).

[0089] 6. Determination of the degradation rate of neutral detergent fibers In vitro rumen fermentation was employed. Rumen fluid from fattening sheep was collected and mixed with buffer at a 1:2 ratio to prepare a culture medium. 0.5 g of the sample was weighed and placed in a culture flask, 50 mL of culture medium was added, CO2 was bubbled through, and the flask was sealed. The flask was then incubated at 39°C for 48 hours. After incubation, the residue was filtered, and the NDF content before and after fermentation was determined according to GB / T 20806-2022 "Determination of Neutral Detergent Fiber in Feed". Degradation rate (%) = (NDF content before fermentation - NDF content after fermentation) / NDF content before fermentation × 100%.

[0090] II. Feeding Effectiveness Evaluation Methods 1. Experimental animals and grouping Healthy fattening Hu sheep of similar weight (28±1.5kg) were selected and randomly divided into groups of 10. The pre-feeding period was 7 days and the formal trial period was 60 days.

[0091] 2. Feeding Management Each group corresponds to a pelleted feed diet prepared according to one example / comparative example, with free access to feed and water. Feed intake was recorded daily, and the diet was weighed every 15 days to calculate the average daily weight gain and feed conversion ratio.

[0092] 3. Daily weight gain measurement Weigh yourself on an empty stomach at the beginning and end of the trial, and every 15 days in the morning. Daily weight gain (g / d) = (final weight - initial weight) / number of trial days.

[0093] 4. Material weight ratio determination Record the amount of feed consumed in each column daily, and calculate the total amount of feed consumed during the trial period. Feed conversion ratio = total feed intake / total weight gain.

[0094] 5. Serum biochemical marker detection At the end of the experiment, 10 sheep were randomly selected from each group, and blood was collected from their jugular veins to separate serum. Total protein, albumin, blood urea nitrogen, and alanine aminotransferase (ALT) in the serum were measured using a fully automated biochemical analyzer.

[0095] 6. Diarrhea rate statistics The number of sheep with diarrhea and the severity of diarrhea in each group were observed and recorded daily. The diarrhea rate (%) was calculated as follows: (number of sheep with diarrhea × number of days with diarrhea) / (number of experimental sheep × number of experimental days) × 100%.

[0096] Example 1 38 92 96.5 3.2 11.8 58.6 Example 2 41 91 95.8 3.5 11.9 57.2 Example 3 35 92 96.1 3.3 11.7 59.1 Example 4 45 92 96.3 3.2 11.8 58.0 Example 5 42 91 96.2 3.3 11.8 57.8 Example 6 40 92 96.4 3.2 11.8 57.5 Example 7 42 91 96.3 3.3 11.9 58.2 Example 8 36 93 96.2 3.2 11.7 58.4 Example 9 39 92 96.4 3.2 11.8 58.5 Example 10 44 93 96.5 3.1 11.7 58.0 Example 11 40 92 96.3 3.2 11.8 57.9 Example 12 39 91 96.0 3.4 11.9 57.6 Example 13 41 92 96.2 3.3 11.8 57.8 Example 14 36 92 96.8 3.0 11.6 62.3 Example 15 38 93 96.5 3.1 11.7 60.5 Example 16 35 92 96.6 3.0 11.6 61.8 Example 17 32 93 96.4 3.2 11.7 59.2 Example 18 35 93 96.3 3.2 11.8 58.8 Example 19 34 92 96.5 3.1 11.7 59.0 Example 20 39 92 94.8 4.2 11.9 58.2 Example 21 38 91 97.2 2.8 11.7 58.5 Example 22 40 93 96.3 3.2 11.8 58.3 Example 23 39 92 96.4 3.2 11.8 58.4 Comparative Example 1 215 91 95.2 4.1 12.0 42.3 Comparative Example 2 112 — 96.1 3.4 11.9 51.2 Comparative Example 3 186 92 96.3 3.3 11.8 57.8 Comparative Example 4 42 92 96.2 3.3 11.8 58.1 Comparative Example 5 40 92 96.0 3.5 11.9 57.5 Comparative Example 6 85 92 96.4 3.2 11.8 52.5 Comparative Example 7 40 91 93.5 6.5 12.1 58.2 Comparative Example 8 39 45 96.3 3.3 11.7 57.9 Example 1 338 6.2:1 68.5 32.6 5.8 35.2 1.2 Example 2 332 6.3:1 67.8 32.1 6.0 36.1 1.5 Example 3 335 6.2:1 68.2 32.4 5.9 35.8 1.3 Example 4 330 6.4:1 67.5 31.9 6.1 36.5 1.8 Example 5 332 6.3:1 67.9 32.0 6.0 36.2 1.6 Example 6 328 6.4:1 67.2 31.8 6.2 36.8 2.0 Example 7 330 6.3:1 67.6 32.0 6.1 36.5 1.7 Example 8 335 6.2:1 68.0 32.3 5.9 35.9 1.4 Example 9 336 6.2:1 68.3 32.5 5.8 35.6 1.3 Example 10 330 6.4:1 67.4 31.8 6.1 36.6 1.9 Example 11 332 6.3:1 67.7 32.0 6.0 36.3 1.7 Example 12 328 6.4:1 67.1 31.7 6.2 36.9 2.1 Example 13 330 6.3:1 67.5 31.9 6.1 36.5 1.8 Example 14 345 6.1:1 69.2 33.1 5.5 34.2 0.8 Example 15 342 6.1:1 68.8 32.8 5.6 34.8 1.0 Example 16 343 6.1:1 69.0 33.0 5.5 34.5 0.9 Example 17 340 6.2:1 68.6 32.7 5.7 35.0 1.1 Example 18 338 6.2:1 68.4 32.5 5.8 35.3 1.2 Example 19 339 6.2:1 68.5 32.6 5.8 35.2 1.2 Example 20 332 6.3:1 67.8 32.1 6.0 36.2 1.6 Example 21 340 6.2:1 68.4 32.5 5.8 35.1 1.2 Example 22 336 6.2:1 68.1 32.3 5.9 35.5 1.3 Example 23 335 6.2:1 68.0 32.2 5.9 35.6 1.4 Comparative Example 1 285 7.3:1 62.5 29.8 7.8 48.5 8.5 Comparative Example 2 302 6.8:1 64.2 30.5 7.2 42.3 3.5 Comparative Example 3 325 6.4:1 66.5 31.5 6.5 38.5 2.2 Comparative Example 4 330 6.3:1 67.2 31.8 6.1 36.8 1.5 Comparative Example 5 328 6.4:1 66.8 31.6 6.3 37.2 2.0 Comparative Example 6 312 6.6:1 65.5 31.0 6.8 40.5 2.8 Comparative Example 7 332 6.3:1 67.5 32.0 6.0 36.2 1.3 Comparative Example 8 315 6.5:1 66.0 31.2 6.6 39.2 1.6 Combining Example 1 and Comparative Example 1 with Tables 1-2, it can be seen that Comparative Example 1, using un-shredded cotton stalks and undetoxified cottonseed meal, had a free gossypol content as high as 215 mg / kg, an NDF degradation rate reduced to 42.3%, a daily weight gain of only 285 g / d, a feed conversion ratio of 7.3:1, and a diarrhea rate of 8.5%. In contrast, Example 1, through shredding treatment and microbial fermentation detoxification, reduced free gossypol to 38 mg / kg, increased the NDF degradation rate to 58.6%, achieved a daily weight gain of 338 g / d, and a feed conversion ratio of 6.2:1. This indicates that shredding cotton stalks and microbial detoxification of cottonseed meal are key prerequisites for improving palatability, reducing anti-nutritional factors, and enhancing digestibility and absorption efficiency.

[0097] Combining Example 1 and Comparative Example 2 with Tables 1-2, it can be seen that in Comparative Example 2, without the addition of the compound enzyme preparation, the NDF degradation rate was only 51.2%, the daily weight gain was 302 g / d, and the material weight ratio was 6.8:1. In Example 1, after adding the compound enzyme preparation containing laccase, the NDF degradation rate increased to 58.6%, the daily weight gain increased to 338 g / d, and the material weight ratio decreased to 6.2:1. This indicates that the compound enzyme preparation, especially laccase, can synergistically degrade fiber and phenolic structures, significantly improving fiber utilization efficiency.

[0098] Combining Example 1 and Comparative Example 3 with Tables 1-2, it can be seen that Comparative Example 3, without the addition of the gossypol detoxification synergist, had a free gossypol content of 186 mg / kg, a daily weight gain of 325 g / d, and urea nitrogen increased to 6.5 mmol / L and alanine aminotransferase to 38.5 U / L, indicating a potential toxicity risk. Example 1, using a ferrous sulfate-vitamin C-montmorillonite ternary system, reduced free gossypol to 38 mg / kg and improved serum biochemical indicators, indicating that the synergist can efficiently complex and adsorb residual gossypol, ensuring feeding safety.

[0099] Combining Example 1 and Comparative Example 4 with Tables 1-2, it can be seen that in Comparative Example 4, replacing rumen-protected methionine with ordinary methionine reduced the daily weight gain to 330 g / d and increased the feed conversion ratio to 6.3:1, while the total protein and albumin levels decreased slightly. In Example 1, using pH-sensitive coated methionine, the daily weight gain was 338 g / d and the feed conversion ratio was 6.2:1, indicating that rumen-protected amino acids can effectively avoid rumen degradation and improve the efficiency of amino acid supply in the small intestine.

[0100] Based on Example 1, Comparative Example 5, and Tables 1-2, it can be seen that Comparative Example 5, using sodium bicarbonate as a single buffer, achieved a daily weight gain of 328 g / d, a feed conversion ratio of 6.4:1, and a diarrhea rate of 2.0%. Example 1, using a mixture of sodium bicarbonate and magnesium oxide in a 4:1 ratio, achieved a daily weight gain of 338 g / d, a feed conversion ratio of 6.2:1, and a diarrhea rate reduced to 1.2%. This indicates that the composite buffer has a synergistic advantage in maintaining rumen pH homeostasis and reducing the risk of acidosis.

[0101] Based on Example 1 and Comparative Example 6, and referring to Tables 1-2, it can be seen that the compound enzyme preparation in Comparative Example 6 does not contain laccase, has a free gossypol content of 85 mg / kg, an NDF degradation rate of 52.5%, a daily weight gain of 312 g / d, and a feed-to-weight ratio of 6.6:1; Example 1 contains 10% laccase, with free gossypol reduced to 38 mg / kg, an NDF degradation rate of 58.6%, and a daily weight gain of 338 g / d, indicating that laccase plays an irreplaceable role in the degradation of gossypol and the destruction of fiber structure.

[0102] Based on Example 1, Comparative Example 7, and Tables 1-2, it can be seen that Comparative Example 7, using a single mixing process, exhibited reduced mixing uniformity, increased pellet pulverization rate to 6.5%, decreased PDI to 93.5%, and achieved a daily weight gain of 332 g / d and a feed conversion ratio of 6.3:1, slightly lower than Example 1. Example 1, using a two-stage mixing process, achieved a pulverization rate of only 3.2% and a PDI of 96.5%, indicating that two-stage mixing helps improve the uniformity of cotton stalk and powder coating, thereby improving pellet quality and feeding effect.

[0103] Based on Example 1, Comparative Example 8, and Tables 1-2, it can be seen that in Comparative Example 8, when the compound enzyme preparation and rumen-protected amino acids were added before conditioning, the enzyme activity retention rate was only 45%, the daily weight gain was reduced to 315 g / d, and the material weight ratio was 6.5:1. In Example 1, the post-coating process was used, and the enzyme activity retention rate reached 92%, with a daily weight gain of 338 g / d. This indicates that post-coating can effectively avoid the inactivation of heat-sensitive enzyme preparations during high-temperature granulation and ensure the effectiveness of functional components.

[0104] Combining Examples 1 and 14-16 with Tables 1-2, it can be seen that after alkali-microwave composite modification of cotton stalks in Examples 14-16, the NDF degradation rate increased to 60.5%~62.3%, the daily weight gain increased to 342~345g / d, the feed conversion ratio decreased to 6.1:1, and the diarrhea rate decreased to 0.8%~1.0%, which is significantly better than that of the unmodified Example 1. This indicates that alkali soaking combined with microwave treatment can effectively destroy the lignin-cellulose structure and significantly improve fiber degradability and production performance.

[0105] Combining Examples 1 and 17-19 with Tables 1-2, it can be seen that Examples 17-19, which used Bacillus subtilis and Saccharomyces cerevisiae for co-fermentation to prepare detoxified cottonseed meal, reduced the free gossypol content to 32-35 mg / kg, the NDF degradation rate to 58.8%-59.2%, and the daily weight gain to 338-340 g / d, which is superior to the chemical detoxification method in Example 1. This indicates that microbial co-fermentation has the dual advantages of detoxification and improved protein utilization.

[0106] Based on Examples 1-13 and Tables 1-2, it can be seen that after adjusting the proportions of each component and functional additives based on Example 1, the free gossypol content in all examples was controlled at 32-45 mg / kg, the NDF degradation rate was maintained at 57.2%-59.1%, the daily weight gain was between 328-338 g / d, and the feed conversion ratio was 6.2-6.4:1, all significantly better than the comparative examples. Among them, Example 1 showed the best performance in terms of daily weight gain and feed conversion ratio. In Examples 12-13, when the ratio of cotton stalks to detoxified cottonseed meal was controlled at 2.1-2.4:1, with a combined proportion of 54%-58%, the daily weight gain was slightly lower than that of Example 1, but the difference was small. In Examples 4-5, 6-7, and 10-11, after adjusting the proportions of detoxifying agents, enzyme preparations, or buffers, the daily weight gain remained stable at 328-332 mg / kg. The g / d indicates that the technical solution of this application can maintain a stable and efficient feeding effect within a wide formula window, with the parameter combination determined in Example 1 showing the best overall performance.

[0107] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A pelleted feed diet based on a combination of cotton by-products, characterized in that, Composed of the following raw materials by dry weight percentage: Cotton stalks 30%–45%; 12%–20% of detoxified cottonseed meal; Energy feed 25%–35%; Mixed oilseed meals 5%–10%; Compound enzyme preparations: 0.1%–0.3%; Gossypol detoxification synergist: 0.3%–0.6%; Rumen-protected amino acids: 0.1%–0.3%; Buffer 0.5%–1.0%; Premixed feed 2.5%–3.5%; Salt content: 0.5%–0.8%; Stone powder 0.5%–1.5%; Calcium hydrogen phosphate 0.3%–1.0%; And the sum of the weight percentages of all components is 100%; The cotton stalks are cotton stalks that have been shredded, with a shred length of 1-3 cm; The detoxified cottonseed meal is cottonseed meal fermented by microorganisms.

2. The pelleted feed ration according to claim 1, characterized in that, The gossypol detoxification synergist comprises ferrous sulfate, vitamin C, and montmorillonite in a mass ratio of (5-10):(1-2):(3-5); the compound enzyme preparation is a mixture of cellulase, xylanase, phytase, and laccase, wherein the mass percentage of laccase is 5%-15%; the rumen-protected amino acid is pH-sensitive coated methionine and / or lysine; the buffer is a mixture of sodium bicarbonate and magnesium oxide in a mass ratio of 3-5:1; the premix contains vitamin A, vitamin D, vitamin E, and amino acid chelated trace elements iron, zinc, manganese, and copper, as well as inorganic iodine, selenium, and cobalt.

3. The pelleted feed ration according to claim 1, characterized in that, The mass ratio of cotton stalks to detoxified cottonseed meal is (2.1-2.4):1, and the two together account for 54%-58% of the total weight of the diet.

4. The pelleted feed ration according to claim 1, characterized in that, The cotton stalks are further modified by the following methods: Soak cotton stalks in a 0.5%–2.0% sodium hydroxide solution at a solid-liquid ratio of 1:3–1:5 for 2–6 hours. After draining, place it in a microwave device and treat it at a microwave power of 500-1000W for 3-8 minutes; Wash with water until neutral, and dry until the moisture content is ≤12% to obtain modified cotton stalks.

5. The pelleted feed ration according to claim 1, characterized in that, The method for preparing the detoxified cottonseed meal includes the following steps: Adjust the moisture content of cottonseed meal to 40%–50%, and inoculate it with Bacillus subtilis and Saccharomyces cerevisiae at inoculation rates of 1%–3% and 0.5%–1.5%, respectively. Solid-state fermentation at 28–37°C for 48–72 hours; Dry until the moisture content is ≤10%, then crush and sieve to obtain detoxified cottonseed meal.

6. A method for preparing a pelleted diet as described in any one of claims 1-5, characterized in that, Includes the following steps: Weigh all raw materials except the compound enzyme preparation according to the proportions described in any one of claims 1-5, mix them evenly, and obtain a mixture. The mixture is conditioned by steam at a temperature of 85–90°C for 5–8 minutes. After conditioning, the moisture content of the mixture is 16%–18%. The conditioned mixture is pressed into granules at a granulation temperature of 85–95℃ and a granule diameter of 6–8 mm. After cooling the granules to room temperature, the compound enzyme preparation was formulated into a liquid and sprayed onto the surface of the cooled granules, and then dried until the moisture content was ≤12.5%.

7. The preparation method according to claim 6, characterized in that, In the granulation step, the compression ratio of the mixture into granules is 1:8 to 1:

10.

8. The preparation method according to claim 6, characterized in that, The solid content of the compound enzyme preparation when formulated into the spraying liquid is 5% to 15%, and the atomization pressure during spraying is 0.2 to 0.4 MPa, and the temperature of the spraying liquid is 25 to 35°C.