Gallnut tannic acid feed for improving calf diarrhea, nitrogen utilization and immunity and preparation method of gallnut tannic acid feed

Abstract

The invention belongs to the technical field of feed preparation, and relates to a gallnut tannic acid feed for improving calf diarrhea, nitrogen utilization and immunity and a preparation method thereof, and the preparation method specifically comprises the following steps: preparing gallnut tannic acid and a gallnut-poplar and willow branch extract, and mixing the gallnut tannic acid and the gallnut-poplar and willow branch extract with a pretreatment base material, puffed corn, mineral salt and probiotics to obtain the gallnut tannic acid feed; by means of natural antibacterial components such as tannic acid and gallic acid in the gallnut extract and means of a multi-stage extraction and fermentation process and the like, the probiotic-antioxidant synergistic effect is achieved, technical breakthrough is achieved in the aspects of replacing antibiotics, improving the nitrogen utilization rate and enhancing immunity, and compared with the prior art, the preparation method has the advantages that the preparation method is simple, and the cost is low. The method has the core advantages that natural components are efficiently utilized, byproducts are recycled and regenerated, multi-target-point functions are coordinated, and a solution with economical efficiency and sustainability is provided for healthy breeding of the calves.

Description

Technical Field

[0001] The invention belongs to the technical field of feed preparation, and particularly relates to a gallnut tannic acid feed capable of improving calf diarrhea, nitrogen utilization and immunity, and a preparation method thereof. Background Art

[0002] Against the backdrop of a comprehensive antibiotic ban in feed, effectively alleviating calf diarrhea has become a pressing technical challenge. Calf diarrhea is one of the most detrimental diseases to calf health, due to its high morbidity and mortality, slowed growth, high treatment costs, and severe impact on later growth and production performance. Calf diarrhea not only slows growth, reduces resistance, and delays calving, but is also the most common cause of mortality in the first 30 days of life, with 57% of weaned calf deaths attributed to diarrhea. Calf diarrhea not only impacts the calf's own growth and development, but also severely impacts herd renewal and the sustainable development of the dairy industry.

[0003] Traditionally, antibiotics (such as tetracycline and bacitracin) have been added to calf feed to prevent or treat diarrhea. However, long-term use of antibiotics can lead to the development of drug-resistant strains, and drug residues can potentially harm human health through the food chain. With the tightening of global anti-antibiotic policies in feed in recent years, adding antibiotics to feed is no longer feasible.

[0004] Probiotics are commonly used in existing feeds to control diarrhea, but the limited effectiveness of a single strain makes them ineffective in achieving both antibacterial and diarrhea-control effects. Calves have a poor ability to digest protein in feed, and existing feeds lack adequate integration of enzymatic hydrolysis and fermentation technologies, resulting in high nitrogen excretion, a waste of resources and environmental pollution. Existing feeds lack targeted immune-boosting ingredients and rely heavily on vitamin or trace element supplementation, which fails to activate the intestinal immune barrier through synergistic effects.

[0005] Therefore, providing a feed that can replace traditional antibiotics and improve nitrogen utilization and immune ability of calves has become an urgent problem to be solved. Summary of the Invention

[0006] In order to solve the above problems, the present invention adds tannic acid to the feed to improve the intestinal function of calves. Tannic acid can increase the abundance of beneficial bacteria, reduce the abundance of potential pathogenic bacteria, and improve antioxidant capacity. However, different types of tannic acid have different chemical structures, and their ability to reduce diarrhea and regulate intestinal function also varies.

[0007] The tannic acid used in the present invention is derived from the Chinese herbal medicine Galla chinensis, which has the highest tannic acid content among plants (60-80%). Therefore, the present invention provides a Galla chinensis tannic acid feed that improves calf diarrhea, nitrogen utilization and immunity.

[0008] The specific preparation method comprises the following steps:

[0009] Step 1: Dry the gallnut and willow branches at 40-50° C. to a moisture content of ≤5%, grind them into 40-50 mesh powder, mix the gallnut powder with an organic acid solution with a pH of 4.5-5.5 at a solid-liquid mass ratio of 1:8, and stir at 40-50° C. and 120-150 rpm for 2-2.5 hours to obtain an activation solution;

[0010] Adding extractant 1 to the activated solution, performing reflux extraction at 70-75° C. for 1.5-2 hours, filtering through a 180-220 mesh filter to obtain a primary filtrate and a primary residue, adding extractant 1 to the primary residue, performing ultrasonic extraction at 50-60° C. and 40-50 kHz for 40-50 minutes, filtering through a 180-220 mesh filter to obtain a secondary filtrate and a secondary residue, combining the primary filtrate and the secondary filtrate, and drying at (-30)° C. to (-20)° C. and 10-20 Pa to obtain gallic tannic acid;

[0011] The secondary filter residue, poplar and willow branch powder and the extractant are mixed, reflux extracted at 70-75° C. for 2-2.5 hours, filtered through a 180-220 mesh filter to obtain a tertiary filtrate and a tertiary filter residue, and the tertiary filtrate is dried at 25-35° C. to obtain a gallnut-poplar and willow branch extract.

[0012] Preferably, the organic acid solution is one or more of acetic acid solution, citric acid solution and lactic acid solution.

[0013] Preferably, the volume ratio of the activation solution to the extractant 1 is 1:1, and the mass ratio of the primary filter residue to the extractant 1 is 1:1. Most preferably, the extractant 1 is anhydrous ethanol.

[0014] Preferably, the mass ratio of the secondary filter residue, poplar and willow branch powder and the second extractant is 2:1:4. Most preferably, the second extractant is ethanol and ethyl acetate in a mass ratio of 2:1.

[0015] Step 2: Grind the corn into 20-30 mesh powder, and then put it into the puffing device for puffing.

[0016] The first stage: 115-125℃, rotation speed 250-280rpm, water content 15-18%.

[0017] The second stage: 95-105℃, rotation speed 300-320rpm, 0.1-0.2MPa water vapor.

[0018] The third stage: 75-85°C, rotation speed 230-250 rpm, (-0.1)-(-0.08) MPa, dehydration to a moisture content of ≤7% to obtain puffed corn.

[0019] Step three, the forage grass, soybean meal, wheat bran and the third-level filter residue are mixed and crushed to 20-30 mesh in a mass ratio of 10:7:3:4 to obtain a base material, the composite bacterial agent is added to the base material, and then the water content is adjusted to 60-70% with an enzymatic hydrolyzate, and fermented at 35-40°C, 50-60% humidity, and 10-12% oxygen concentration for 12-14 hours, during which the fermentation is stirred once every 1.5-2 hours, and then statically fermented at 45-50°C, 55-65% humidity, and 12-15% carbon dioxide concentration for 24-26 hours, and then matured at 55-60°C and 25-30% humidity for 12-14 hours. After the fermentation is completed, the base material is inactivated at 90-95°C for 15-20 minutes to obtain the pretreated base material.

[0020] Preferably, the mass ratio of the base material to the composite bacterial agent is 50:1.

[0021] Preferably, the composite bacterial agent is an EM bacterial agent.

[0022] Preferably, the enzymatic hydrolysis solution comprises 1800-2200 U / g of cellulase, 4800-5200 U / g of xylanase and 3800-4200 U / g of protease.

[0023] Step 4: The pretreated base material, puffed corn, gallnut tannic acid, gallnut-willow branch extract, mineral salts and probiotics are mixed and granulated in a mass ratio of (60-65):(30-35):(3-5):(10-12):(1-2):(0.1-0.2) to obtain a particle size of 3-5 mm and a particle moisture content of ≤8% to obtain a gallnut tannic acid feed.

[0024] Preferably, the mineral salts include sodium chloride, calcium hydrogen phosphate and magnesium sulfate in a mass ratio of 3:1:2.

[0025] Preferably, the probiotics include lactic acid bacteria and yeast in a mass ratio of 3:1.

[0026] The present invention has the following advantages:

[0027] (1) The present invention uses natural antibacterial ingredients (tannic acid) to replace antibiotics. Tannic acid has strong astringency, can reduce intestinal water exudation, directly inhibit the adhesion and proliferation of pathogens (such as Escherichia coli and Salmonella), and repair intestinal mucosal damage through antioxidant and anti-inflammatory effects. Compared with traditional feed, diarrhea can be controlled without antibiotics, avoiding drug resistance and residual risks.

[0028] (2) The present invention adopts a multi-stage extraction process of organic acid activation + reflux extraction + ultrasound-assisted extraction to improve the utilization rate of active ingredients. The citric acid solution activation combined with ethanol step-by-step extraction is used to significantly improve the extraction rate of tannic acid compared with the traditional water extraction method. Freeze vacuum drying retains the activity of heat-sensitive components and avoids the degradation of heat-sensitive components caused by traditional high-temperature drying.

[0029] (3) Secondary filter residue and tertiary filter residue are reused. The present invention mixes the secondary filter residue with willow branches for extraction, further utilizes the active ingredients in the secondary filter residue, and combines salicylic acid to further improve intestinal function; the present invention mixes the tertiary filter residue (rich in cellulose) with soybean meal and wheat bran for fermentation, and generates small molecule peptides and short-chain fatty acids after enzymatic hydrolysis by cellulase and protease, significantly improving protein digestibility and nitrogen utilization rate, dynamically adjusting temperature, humidity and gas environment, promoting EM bacterial agent enzyme production, further decomposing anti-nutritional factors, and releasing available nitrogen sources.

[0030] (4) Probiotics and antioxidants synergistically enhance immunity. Lactic acid bacteria inhibit the colonization of pathogenic bacteria. Yeast metabolites (such as β-glucan) activate intestinal immune cells. Antioxidants scavenge free radicals and reduce the damage of oxidative stress to the intestinal mucosa, forming a double immune protection with gallnut extract.

[0031] (5) The present invention generates porous corn granules through gradient temperature and pressure regulation, thereby increasing starch gelatinization and improving energy supply efficiency. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0033] Example 1

[0034] Step 1: Dry the gallnut and willow branches at 45°C to a moisture content of ≤5%, then grind them into 45-mesh powder. Mix the gallnut powder with a pH 5.0 citric acid solution at a solid-liquid mass ratio of 1:8, and stir at 45°C and 120 rpm for 2 hours to obtain an activation solution.

[0035] Extractant 1 was added to the activation solution at a volume ratio of 1:1, and reflux extraction was carried out at 72°C for 2 hours. After filtering through a 200-mesh filter, a primary filtrate and a primary residue were obtained. Extractant 1 was added to the primary residue at a mass ratio of 1:1, and ultrasonic extraction was carried out at 55°C and 40kHz for 40 minutes. After filtering through a 200-mesh filter, a secondary filtrate and a secondary residue were obtained. The primary filtrate and the secondary filtrate were combined and dried at -25°C and 15Pa to obtain gallic tannic acid.

[0036] The secondary filter residue, poplar and willow branch powder, and extractant 2 were mixed in a mass ratio of 2:1:4, and refluxed at 72°C for 2 hours. After filtering through a 200-mesh filter, a tertiary filtrate and a tertiary filter residue were obtained. The tertiary filtrate was dried at 28°C to obtain the Chinese gallnut-poplar and willow branch extract. The extractant 1 was anhydrous ethanol, and the extractant 2 was ethanol and ethyl acetate in a mass ratio of 2:1.

[0037] Step 2: Grind the corn into 25 mesh powder and then put it into the puffing device for puffing.

[0038] The first stage: 120℃, rotation speed 250rpm, material moisture content 17%.

[0039] The second stage: 100℃, rotation speed 300rpm, injection of 0.1MPa water vapor.

[0040] The third stage: 80°C, rotation speed 230 rpm, -0.08 MPa, dehydration to a moisture content of ≤7%, to obtain puffed corn.

[0041] Step 3: Mix and grind the grass, soybean meal, wheat bran and tertiary filter residue in a mass ratio of 10:7:3:4 to 25 mesh to obtain a base material, add EM bacterial agent to the base material in a mass ratio of 50:1, and then adjust the water content to 65% with enzymatic solution, ferment for 12 hours at 35°C, 55% humidity, and 12% oxygen concentration, and stir once every 2 hours. Then, static fermentation for 24 hours at 45°C, 60% humidity, and 13% carbon dioxide concentration, and then mature for 12 hours at 60°C and 28% humidity. After fermentation is completed, inactivate at 90°C for 15 minutes to obtain a pretreated base material. The enzymatic solution includes 1800-2200U / g of cellulase, 4800-5200U / g of xylanase, and 3800-4200U / g of protease.

[0042] Step 4: The pretreated base material, puffed corn, gallnut tannic acid, gallnut-willow branch extract, mineral salts, and probiotics are mixed and granulated in a mass ratio of 63:32:5:12:1:0.1 to obtain a gallnut tannic acid feed with a particle size of 3-5 mm and a moisture content of ≤8%. The mineral salts include sodium chloride, calcium hydrogen phosphate, and magnesium sulfate in a mass ratio of 3:1:2. The probiotics include lactic acid bacteria and yeast in a mass ratio of 3:1.

[0043] Test Example 1

[0044] 1. Experimental Animals

[0045] Forty three-month-old Holstein calves with good health, body condition and birth weight were roughly the same, with an average weight of 98.1 kg. They were evenly divided into four groups, with 10 calves in each group.

[0046] Experimental group: The mice were fed with the feed containing gallnut tannic acid prepared according to the method of Example 1.

[0047] Control group 1: fed with the feed prepared according to the method of Example 1, but without gallnut tannic acid.

[0048] Control group 2: The rats were fed with the feed containing gallnut tannic acid prepared according to the method of Example 1, but without the gallnut-willow branch extract.

[0049] Control group 3: The mice were fed with the feed prepared according to the method of Example 1, but without the gallnut tannic acid and gallnut-willow branch extract.

[0050] 2. Feeding methods and cycles

[0051] Except for the type of feed, the rest of the feeding methods were referred to the Key Technologies for Calf Feeding and Management, written by Sun Peng. The feed amounts for 1-3 days in the experimental and control groups were the same, and the feeding cycle was 45 days.

[0052] 3. Detection indicators

[0053] The content of tannic acid in gallnut tannins and the content of active ingredients in gallnut-willow branch extract were determined.

[0054] The animals were weighed before the start of the experiment and before morning feeding on day 45, and their daily weight gain and feed-to-weight ratio were calculated.

[0055] On the 45th day, blood samples were collected using anticoagulant blood collection tubes before morning feeding. After centrifugation at 2000 rpm for 10 min, plasma samples were collected to detect the levels of IgA, IgG and TNF-α in the blood.

[0056] The diarrhea rate was calculated and averaged daily. The digestion and metabolism test started on the 30th day. Fecal and urine samples were collected using the full fecal collection method to detect nitrogen deposition, urinary nitrogen excretion, urinary nitrogen excretion / nitrogen intake, and nitrogen deposition / nitrogen intake.

[0057] Table 1 Active ingredients in the Gallnut-Willow Branch Extract

[0058] Gallnut tannic acid Gallnut-Willow Branch Extract Tannic acid (mg / g extract) 582.5±15.3 0.47±0.05 Salicylic acid (mg / g extract) - 452.5±11.6

[0059] Table 2 Evaluation results of calf weight gain, nitrogen utilization and plasma immune indicators

[0060] index Experimental group Control group 1 Control group 2 Control group 3 Daily weight gain from 1 to 45 days (kg / day) 1.165 1.106 1.106 1.038 Feed to weight ratio (kg / kg) 3.83 3.88 3.82 4.25 Diarrhea rate (%) 0.0196 17.9 0.0478 28.6 Nitrogen deposition (g / d) 37.1 48.5 43.6 38.3 Urinary nitrogen excretion (g / d) 25.1 33.1 31.8 39.1 Urinary nitrogen excretion / nitrogen intake (g / g) 0.212 0.249 0.232 0.303 Nitrogen deposition / nitrogen intake (g / g) 0.307 0.363 0.346 0.293 IgA content (μg / mL) 2326 2028 2151 1925 IgG content (g / L) 34.8 31.7 33.7 31.2 TNF-α (pg / mL) 346 366 354 383

[0061] As shown in Tables 1-2, the gallnut tannic acid and gallnut-willow branch extracts prepared in the present invention are rich in active ingredients such as tannic acid and salicylic acid, and can significantly control diarrhea in calves, improve nitrogen utilization, and enhance calf immunity. The experimental groups showed significantly higher daily weight gain than control groups 1-3. Furthermore, compared with control groups 1-3, the experimental groups showed significantly lower feed-to-weight ratios, urinary nitrogen excretion, diarrhea rates, and plasma TNF-α levels, while significantly increasing nitrogen deposition and plasma IgA levels.

[0062] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a gallnut tannic acid feed for improving calf diarrhea, nitrogen utilization and immunity, characterized in that: The following steps are involved: Step 1: Mix and dry the gallnuts and willow branches, grind them, and mix the gallnut powder with an organic acid solution in a solid-liquid manner to obtain an activation solution; Step 2: adding extractant 1 to the activation solution, performing reflux extraction, and filtering to obtain a primary filtrate and a primary filter residue; adding extractant 1 to the primary filter residue, performing ultrasonic extraction, and filtering to obtain a secondary filtrate and a secondary filter residue; combining the primary filtrate and the secondary filtrate, and freeze-drying in a vacuum to obtain gallnut tannic acid; The secondary filter residue, poplar and willow branch powder and extractant 2 are mixed, reflux extracted, filtered to obtain a tertiary filtrate and a tertiary filter residue, and the tertiary filtrate is dried to obtain a gallnut-poplar and willow branch extract; Step 3: Mix and granulate the pretreated base material, puffed corn, gallnut tannic acid, gallnut-willow branch extract, mineral salts and probiotics in a mass ratio of (60-65):(30-35):(3-5):(10-12):(1-2):(0.1-0.2) to obtain gallnut tannic acid feed.

2. The method for preparing the gallnut tannic acid feed according to claim 1, wherein The extractant 1 in step 2 is anhydrous ethanol.

3. The method for preparing the gallnut tannic acid feed according to claim 1, wherein In step 2, the volume ratio of the activation solution to the extractant 1 is 1:1, and the mass ratio of the primary filter residue to the extractant is 1:

1.

4. The method for preparing the gallnut tannic acid feed according to claim 1, wherein The mass ratio of the secondary filter residue, willow branch powder and extractant 2 in step 2 is 2:1:4, and the extractant 2 is ethanol and ethyl acetate in a mass ratio of 2:

1.

5. The method for preparing the gallnut tannic acid feed according to claim 1, wherein The preparation method of the pretreated base material described in step three is to mix and grind forage grass, soybean meal, wheat bran and tertiary filter residue to obtain a base material, add a composite bacterial agent to the base material, and then adjust the moisture content with an enzymatic hydrolyzate. Ferment for 12-14 hours at 35-50°C, 50-60% humidity, and 10-12% oxygen concentration, turning it over every 1.5-2 hours, and then statically ferment for 24-26 hours at 45-50°C, 55-65% humidity, and 12-15% carbon dioxide concentration, and then mature for 12-14 hours at 55-60°C and 25-30% humidity. After fermentation is completed, inactivate at 90-95°C for 15-20 minutes to obtain the pretreated base material.

6. The method for preparing the gallnut tannic acid feed according to claim 5, wherein: The composite bacterial agent is an EM bacterial agent.

7. The method for preparing the gallnut tannic acid feed according to claim 5, wherein: The enzymatic hydrolysis solution comprises 1800-2200 U / g of cellulase, 4800-5200 U / g of xylanase and 3800-4200 U / g of protease.

8. The method for preparing the gallnut tannic acid feed according to claim 1, wherein: The mineral salts in step 3 include sodium chloride, calcium hydrogen phosphate and magnesium sulfate in a mass ratio of 3:1:

2.

9. The method for preparing the gallnut tannic acid feed according to claim 1, wherein: The probiotics described in step 3 include lactic acid bacteria and yeast, with a mass ratio of 3:

1.

10. Gallnut tannic acid feed prepared by the method according to any one of claims 1 to 9.