阅读说明：本技术 一种包膜小分子有机酸组合物及其制备方法和应用 (Coated small-molecule organic acid composition and preparation method and application thereof ) 是由 萧文聪 闫方权 吴世林 江华峰 于 2020-12-29 设计创作，主要内容包括：本发明提供一种包膜小分子有机酸组合物及其制备方法和应用,所述包膜小分子有机酸组合物,包括酸化剂,酸化剂包括组分：小分子有机酸、吸附剂、螯合剂和稳定剂。本发明使用螯合剂、稳定剂和/或粘合剂可以很好地和小分子有机酸进行螯合,并且在稳定剂和粘合剂的稳定体系内可以很好防止小分子有机酸的挥发损失。所述包膜小分子有机酸组合物还包括包膜层,使用两种包膜材料可以很好保护小分子有机酸,防止其穿透,第二包膜层为脂类包膜层,其在胃中不溶解,可以靶向地在各肠道中缓解释放,特别是还能降低消化道中后段的pH,使其成为不利于致病性有害菌生长的环境,从而减少动物的腹泻和其他疾病的发生几率。(The invention provides an coated small-molecule organic acid composition and a preparation method and application thereof, wherein the coated small-molecule organic acid composition comprises an acidifier, and the acidifier comprises the following components: small molecule organic acid, adsorbent, chelating agent and stabilizer. The chelating agent, the stabilizing agent and/or the binding agent can be well chelated with the small-molecular organic acid, and the volatilization loss of the small-molecular organic acid can be well prevented in a stabilizing system of the stabilizing agent and the binding agent. The coated small molecular organic acid composition also comprises a coating layer, the two coating materials can well protect the small molecular organic acid and prevent the small molecular organic acid from penetrating, the second coating layer is a lipid coating layer which is insoluble in stomach and can be released in various intestinal tracts in a targeted manner, and particularly, the pH value of the middle and later sections of the digestive tract can be reduced, so that the coated small molecular organic acid composition becomes an environment which is not beneficial to the growth of pathogenic harmful bacteria, and the occurrence probability of diarrhea and other diseases of animals is reduced.)

1. An enveloped small molecule organic acid composition characterized by: comprises an acidifier which comprises the following components: small molecule organic acid, adsorbent, chelating agent and stabilizer.

2. The coated small molecule organic acid composition of claim 1, wherein: the acidulant also includes a binder.

3. The coated small molecule organic acid composition of claim 1, wherein: the mass ratio of the small molecular organic acid to the adsorbent is (1.5-2): 1.

4. the coated small molecule organic acid composition of claim 1, wherein: the mass of the chelating agent accounts for 5-10% of the total mass of the coated small molecular organic acid composition.

5. The coated small molecule organic acid composition of claim 1, wherein: the mass of the stabilizer accounts for 0.01-1% of the total mass of the coated small molecular organic acid composition.

6. The coated small molecule organic acid composition of claim 1, wherein: the film packaging structure further comprises a film packaging layer, wherein the film packaging layer comprises a first film packaging layer and a second film packaging layer.

7. The coated small molecule organic acid composition of claim 6, wherein: the first coating layer coats the acidifying agent, and the second coating layer coats the first coating layer.

8. The coated small organic acid composition of claim 6 or 7, wherein: the mass of the first coating layer accounts for 1-2% of the total mass of the coated small molecular organic acid composition; preferably, the mass of the second coating layer accounts for 7-15% of the total mass of the coated small molecular organic acid composition.

9. A method for preparing the coated small organic acid composition according to any one of claims 1 to 8, comprising the steps of:

(1) stirring and chelating the raw materials except the adsorbent, adding the adsorbent, mixing, and then extruding and granulating to obtain acidulant particles;

(2) and (2) placing the acidulant particles obtained in the step (1) in a stirrer, wrapping the first coating layer and then the second coating layer, and sieving to obtain the coated small-molecule organic acid composition.

10. Use of the coated small organic acid composition according to any one of claims 1 to 8 in animal feed.

Technical Field

The invention belongs to the technical field of animal feed additives, and particularly relates to an enveloped small-molecular organic acid composition and a preparation method and application thereof.

Background

Because the digestive tract of young animals is not well developed, the activity of digestive enzymes is not enough, particularly the activity of pepsin is reduced, most of daily ration protein enters the middle and rear segments of the digestive tract without being fully digested, a large amount of undigested and absorbed protein is fermented, harmful substances are generated, and diarrhea is caused. Therefore, the activity of pepsin is improved, the digestibility of protein in the front section of the digestive tract, particularly in the stomach and the intestine is improved, and the activity has an important effect on reducing the diarrhea of weaned piglets.

After the 21 st century, the concern of human beings on food safety has been unprecedented, the prohibition of antibiotics and other chemicals to prevent harm such as drug residue is a necessary path for the development of global aquaculture, and as the current situation of continuously increasing diseases and stress factors for the intensive and large-scale development of global aquaculture, people are forced to seek substitutes for antibiotics and other drugs to ensure the safety and stability of animal production. As one of acidifiers, small molecular organic acids such as formic acid can lower the pH of the stomach and promote the digestion of protein; more importantly, in addition to digestive acids, it acts as intestinal bacteriostatic acid, inhibiting bacteria in molecular form at different locations in the intestine, thereby preventing disease and weaning diarrhea. And the small molecular acid such as formic acid has weak killing performance on beneficial bacteria, can adjust the flora balance in intestinal tracts, and can indirectly adjust the immunity through a signal path. In patent CN107821788A, monoglyceride is mentioned to be used for coating small molecular acid, but the formic acid and other small molecular organic acids have strong penetrating power and are difficult to be directly coated, and the monoglyceride is solidified relatively slowly and is basically impossible to coat in a fluidized bed, so that the process has defects; patent CN101965909A also mentions an acidulant coating, but the same problem can also exist. And small molecular acids such as formic acid and the like are active in nature, easy to volatilize and strong in penetrating power and difficult to effectively wrap.

Disclosure of Invention

The invention aims to overcome the defects of easy moisture absorption, easy volatilization, unstable property and the like of a product caused by high irritation and corrosion of an acidifier in the prior art, and provides a coated small-molecular organic acid composition, a preparation method and application thereof.

The technical scheme adopted by the invention is as follows:

in a first aspect of the present invention, there is provided:

an encapsulated small molecule organic acid composition comprising an acidulant comprising the following components: small molecule organic acid, adsorbent, chelating agent and stabilizer.

Preferably, the acidulant also includes a binder.

Preferably, the mass ratio of the small-molecular organic acid to the adsorbent is (1.5-2): 1, the micromolecular organic acid and the adsorbent with the mass ratio are selected, so that the micromolecular organic acid can meet the requirement of extrusion granulation.

Preferably, the mass of the chelating agent accounts for 5-10% of the total mass of the coated small molecular organic acid composition. The use of chelating agents in this ratio results in the best results.

Preferably, the mass of the stabilizer and/or the adhesive accounts for 0.01-1% of the total mass of the coated small molecular organic acid composition. The addition amount of the stabilizer and the adhesive is not suitable to be too much or too little, the excessive addition can cause the material of the whole coated small molecular organic acid composition to be too thick, the subsequent processing of the coated small molecular organic acid composition is influenced, the stabilizing effect and the adhesive effect generated by the too little addition are insufficient, and the formed coated small molecular organic acid composition particles are unstable. The stabilizer and the adhesive in percentage by mass can ensure that the material of the coated small molecular organic acid composition has moderate consistency, good viscosity and easy processing and granulation, and the obtained coated small molecular organic acid composition has better and more stable particle formation.

Preferably, the small-molecule organic acid is at least one selected from formic acid, acetic acid and propionic acid.

Preferably, the adsorbent is at least one selected from the group consisting of silica and rice bran.

Preferably, the chelating agent is at least one selected from the group consisting of calcium lignosulfonate and sodium lignosulfonate.

Preferably, the stabilizer is at least one selected from xanthan gum, carrageenan and hydroxypropyl cellulose sodium.

Preferably, the binder is at least one selected from xanthan gum and sodium alginate.

Preferably, the coated small molecule organic acid composition further comprises a coating layer, wherein the coating layer comprises a first coating layer and a second coating layer.

Preferably, the first coating layer covers the acidifying agent, and the second coating layer covers the first coating layer. The two coating layers can better protect active micromolecular organic acid with strong volatile penetrating power, and the second coating layer can also better protect the acidifier to slowly release formic acid in gastric juice, so that the loss of the formic acid in the stomach is reduced.

Preferably, the mass of the first coating layer accounts for 1-2% of the total mass of the coated small molecular organic acid composition.

Preferably, the mass of the second coating layer accounts for 7-15% of the total mass of the coated small molecular organic acid composition.

Preferably, the first coating layer comprises polyacrylic resin containing 8% to 15% of ethanol.

Preferably, the polyacrylic acid resin is a type II polyacrylic acid resin.

Preferably, the second coating layer is at least one selected from rice bran wax, hydrogenated oil, and shortening.

Preferably, the melting point of the rice bran wax, the hydrogenated oil or the shortening is 60 to 70 ℃.

In a second aspect of the present invention, there is provided:

a preparation method of the coated small molecular organic acid composition comprises the following steps:

(1) stirring and chelating the raw materials except the adsorbent, adding the adsorbent, mixing, and then extruding and granulating to obtain acidulant particles;

(2) and (2) placing the acidulant particles obtained in the step (1) in a stirrer, wrapping the first coating layer and then the second coating layer, and sieving to obtain the coated small-molecule organic acid composition.

Preferably, the extrusion granulator used in the extrusion granulation in the step (1) is a circular arc surface rotary extrusion granulator.

Preferably, the rotating speed of the extrusion granulator is 40-60 r/min, and the aperture of the screen mesh of the extrusion granulator is 0.6-0.9 mm.

Preferably, the stirrer in the step (2) is a tank-type stirrer, and the tank-type stirrer is provided with a jacket capable of controlling temperature and adjusting steering.

Preferably, in the step (2), the first coating layer and the second coating layer are respectively coated by a peristaltic pump and a spray gun.

Preferably, the atomization pressure of the spray gun is 0.2-0.5 MPa when the first coating layer is coated, and the liquid conveying capacity of the peristaltic pump is 100-200 g/min.

Preferably, the atomization pressure of the spray gun is 0.2-0.5 MPa when the second coating layer is coated, the liquid conveying capacity of the peristaltic pump is 0.5-1.0 Kg/min, and the temperature of the jacket of the groove type stirrer is 45-50 ℃.

In a third aspect of the present invention, there is provided:

an application of the coated micromolecular organic acid composition in animal feed.

The invention has the beneficial effects that:

(1) the chelating agent, the stabilizing agent and/or the binding agent can be well chelated with the small-molecule organic acid, and the volatilization loss of the small-molecule organic acid can be well prevented in a stabilizing system of the stabilizing agent and/or the binding agent.

(2) The effective content of the micromolecule organic acid is more than 40 percent, and the micromolecule organic acid can be well protected by using two coating materials, so that unnecessary loss caused by penetration of the micromolecule organic acid is avoided; and the second coating layer is a lipid coating layer which is insoluble in the stomach and can release small molecular organic acid in each intestinal tract in a targeted manner, and particularly, the pH value of the middle and rear sections of the digestive tract can be reduced, so that the second coating layer becomes an environment which is not beneficial to the growth of harmful bacteria such as pathogenic escherichia coli, salmonella and the like, and the occurrence rate of diarrhea and other diseases of animals is reduced.

(3) The preparation method of the coated small-molecular organic acid composition has the advantages of simple process flow, wide raw material source and low production cost, is suitable for industrial popularization, can replace antibiotics to a certain extent, and has good social and economic benefits.

Detailed Description

In order to make the objects, technical solutions and technical effects of the present invention more clear, the present invention will be described in further detail with reference to specific embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Example 1: an enveloped micromolecular organic acid composition and a preparation method thereof are as follows:

taking 60Kg of formic acid with the mass concentration of 90 percent, adding calcium lignosulfonate (the adding amount is 6.0 percent of the total mass of the coated micromolecule organic acid composition) and xanthan gum (the adding amount is 0.5 percent of the total mass of the coated micromolecule organic acid composition), starting stirring and mixing for 20min under a sealed environment, adding 37.5Kg of white carbon black (the mass ratio of the formic acid to the white carbon black is 1.6:1) to adsorb and mix uniformly, feeding into a rotary extrusion granulator (the rotating speed is 50r/min, and the aperture is 0.6mm) for granulation, and sieving by a 30-mesh sieve. Wrapping the coating layer by using a peristaltic pump and a spray gun, and coating by using a II type polypropylene resin solution containing 10% ethanol for the first time (the addition amount is 1.0% of the total mass of the coated micromolecule organic acid composition, the atomization pressure of the spray gun is 0.3MPa, and the liquid delivery capacity of the peristaltic pump is 130 g/min); the second coating is performed by using rice bran wax with the melting point of 68 ℃ (the addition amount is 8.0% of the total mass of the coated small molecular organic acid composition, the temperature of the rice bran wax during coating is 85 ℃, the jacket temperature of a groove-shaped mixer is 48 ℃, the atomizing pressure of a spray gun is 0.3MPa, and the liquid output of a peristaltic pump is 600g/min), and finally magnesium stearate accounting for 0.5% of the total mass of the coated small molecular organic acid composition is added into the coated small molecular organic acid composition to be dispersed, and the mixture is sieved by a 20-mesh screen to obtain the stable coated small molecular organic acid composition.

Example 2: an enveloped micromolecular organic acid composition and a preparation method thereof are as follows:

taking 60Kg of 90% formic acid and acetic acid mixed solution (the volume ratio of formic acid to acetic acid is 1:1), adding calcium lignosulfonate (the addition amount is 8.0% of the total mass of the coated micromolecule organic acid composition) and xanthan gum (the addition amount is 0.5% of the total mass of the coated micromolecule organic acid composition), starting stirring and mixing for 20min under a sealed environment, adding 35.3Kg of white carbon black ((formic acid + acetic acid): the mass ratio of white carbon black is 1.7:1), adsorbing and mixing uniformly, feeding into a rotary extrusion granulator (the rotating speed is 50r/min, the aperture is 0.6mm), granulating, and sieving by a 30-mesh sieve. Wrapping the coating layer by using a peristaltic pump and a spray gun, and coating by using a II type polypropylene resin solution containing 10% ethanol for the first time (the addition amount is 1.0% of the total mass of the coated micromolecule organic acid composition, the atomization pressure of the spray gun is 0.3MPa, and the liquid delivery capacity of the peristaltic pump is 150 g/min); and the second coating is carried out by using hydrogenated oil with the melting point of 68 ℃ (the addition amount is 10.0% of the total mass of the coated small molecular organic acid composition, the temperature of the hydrogenated oil during coating is 85 ℃, the jacket temperature of a groove-shaped mixer is 48 ℃, the atomizing pressure of a spray gun is 0.3MPa, and the liquid output of a peristaltic pump is 700g/min), and finally, magnesium stearate accounting for 0.5% of the total mass of the coated small molecular organic acid composition is added into the coated small molecular organic acid composition to be dispersed, and the mixture is sieved by a 20-mesh screen to obtain the stable coated small molecular organic acid composition.

Example 3: an enveloped micromolecular organic acid composition and a preparation method thereof are as follows:

taking 60Kg of 90 mass percent of mixed solution of formic acid, acetic acid and propionic acid (the volume ratio of the formic acid to the acetic acid to the propionic acid is 2: 1:1), adding calcium lignosulfonate (the addition amount is 10.0 percent of the total mass of the coated micromolecule organic acid composition) and xanthan gum (the addition amount is 1.0 percent of the total mass of the coated micromolecule organic acid composition), starting stirring and mixing for 20min under a sealed environment, adding 33.3Kg of white carbon black ((the formic acid + the acetic acid + the propionic acid): the mass ratio of the white carbon black is 1.8:1), adsorbing and mixing uniformly, feeding into a rotary extrusion granulator (the rotating speed is 50r/min, the aperture is 0.6mm), granulating, and sieving by a 30-mesh sieve. Wrapping the coating layer by using a peristaltic pump and a spray gun, and coating by using a II type polypropylene resin solution containing 11% ethanol for the first time (the addition amount is 1.5% of the total mass of the coated micromolecule organic acid composition, the atomization pressure of the spray gun is 0.3MPa, and the liquid delivery capacity of the peristaltic pump is 180 g/min); and the second coating is performed by using shortening with the melting point of 38 ℃ (the addition amount is 12.0% of the total mass of the coated small molecular organic acid composition, the temperature of the shortening during coating is 85 ℃, the jacket temperature of a groove type mixer is 48 ℃, the atomizing pressure of a spray gun is 0.3MPa, and the liquid output of a peristaltic pump is 800g/min), and finally, the coated small molecular organic acid composition coated with the coating layer is added into magnesium stearate accounting for 0.5% of the total mass of the coated small molecular organic acid composition for dispersion, and then the magnesium stearate is sieved by a 20-mesh screen to obtain the stable coated small molecular organic acid composition.

Comparative example 1: an enveloped micromolecular organic acid composition and a preparation method thereof are as follows:

taking 60Kg of formic acid with the mass concentration of 90 percent, adding xanthan gum (the addition amount is 0.5 percent of the total mass of the coated micromolecule organic acid composition), starting stirring and mixing for 20min under a sealed environment, adding 37.5Kg of white carbon black (the mass ratio of the formic acid to the white carbon black is 1.6:1) to adsorb and mix uniformly, feeding the mixture into a rotary extrusion granulator (the rotating speed is 50r/min, the pore diameter is 0.6mm) for granulation, and sieving the mixture by a 30-mesh sieve. Wrapping the coating layer by using a peristaltic pump and a spray gun, and coating by using a II type polypropylene resin solution containing 10% ethanol for the first time (the addition amount is 1.0% of the total mass of the coated micromolecule organic acid composition, the atomization pressure of the spray gun is 0.3MPa, and the liquid delivery capacity of the peristaltic pump is 130 g/min); the second coating is performed by using rice bran wax with the melting point of 68 ℃ (the addition amount is 8.0% of the total mass of the coated small molecular organic acid composition, the temperature of the rice bran wax during coating is 85 ℃, the jacket temperature of a groove-shaped mixer is 48 ℃, the atomizing pressure of a spray gun is 0.3MPa, and the liquid output of a peristaltic pump is 600g/min), finally, magnesium stearate accounting for 0.5% of the total mass of the coated small molecular organic acid composition is added into the coated small molecular organic acid composition to be dispersed, and the mixture is sieved by a 20-mesh screen to obtain the stable coated small molecular organic acid composition.

Comparative example 2: an enveloped micromolecular organic acid composition and a preparation method thereof are as follows:

60Kg of a 90% formic acid/acetic acid mixed solution (the volume ratio of formic acid to acetic acid is 1:1) is added with calcium lignosulfonate (the addition amount is 8.0% of the total mass of the coated small molecular organic acid composition), after stirring and mixing are started for 20min in a sealed environment, 35.3Kg of white carbon black ((formic acid + acetic acid): the mass ratio of white carbon black is 1.7:1) is added for uniform adsorption and mixing, the mixture is fed into a rotary extrusion granulator (the rotating speed is 50r/min, the pore diameter is 0.6mm) for granulation, and a 30-mesh screen is screened. Wrapping the coating layer by using a peristaltic pump and a spray gun, and coating by using a II type polypropylene resin solution containing 10% ethanol for the first time (the addition amount is 1.0% of the total mass of the coated micromolecule organic acid composition, the atomization pressure of the spray gun is 0.3MPa, and the liquid delivery capacity of the peristaltic pump is 150 g/min); and the second coating is carried out by using hydrogenated oil with the melting point of 68 ℃ (the addition amount is 10.0% of the total mass of the coated small molecular organic acid composition, the temperature of the hydrogenated oil during coating is 85 ℃, the jacket temperature of a groove-shaped mixer is 48 ℃, the atomizing pressure of a spray gun is 0.3MPa, and the liquid output of a peristaltic pump is 700g/min), and finally, magnesium stearate accounting for 0.5% of the total mass of the coated small molecular organic acid composition is added into the coated small molecular organic acid composition to be dispersed, and the mixture is sieved by a 20-mesh screen to obtain the stable coated small molecular organic acid composition.

Comparative example 3: an enveloped micromolecular organic acid composition and a preparation method thereof are as follows:

taking 60Kg of 90 mass percent of mixed solution of formic acid, acetic acid and propionic acid (the volume ratio of the formic acid to the acetic acid to the propionic acid is 2: 1:1), adding calcium lignosulfonate (the addition amount is 10.0 percent of the total mass of the coated micromolecule organic acid composition) and xanthan gum (the addition amount is 1.0 percent of the total mass of the coated micromolecule organic acid composition), starting stirring and mixing for 20min under a sealed environment, adding 33.3Kg of white carbon black ((the formic acid + the acetic acid + the propionic acid): the mass ratio of the white carbon black is 1.8:1), adsorbing and mixing uniformly, feeding into a rotary extrusion granulator (the rotating speed is 50r/min, the aperture is 0.6mm), granulating, and sieving by a 30-mesh sieve. Wrapping the coating layer by using a peristaltic pump and a spray gun, wrapping the coating layer by using a II type polypropylene resin solution containing 11% ethanol (the addition amount is 1.5% of the total mass of the coated micromolecule organic acid composition, the atomization pressure of the spray gun is 0.3MPa, and the liquid output of the peristaltic pump is 180g/min), finally adding magnesium stearate accounting for 0.5% of the total mass of the coated micromolecule organic acid composition into the coated micromolecule organic acid composition for dispersing, and then sieving by using a 20-mesh sieve to obtain the stable coated micromolecule organic acid composition.

Comparative example 4: an acidifier and its preparation method are disclosed:

taking 60Kg of formic acid with the mass concentration of 90 percent, adding calcium lignosulfonate (the adding amount is 6.0 percent of the total mass of the coated micromolecule organic acid composition) and xanthan gum (the adding amount is 0.5 percent of the total mass of the coated micromolecule organic acid composition), starting stirring and mixing for 20min under a sealed environment, adding 37.5Kg of white carbon black (the mass ratio of the formic acid to the white carbon black is 1.6:1) to adsorb and mix uniformly, feeding into a rotary extrusion granulator (the rotating speed is 50r/min, and the aperture is 0.6mm) for granulation, and sieving by a 30-mesh sieve to obtain acidulant granules.

Test example 1: stability assessment of coated Small molecule organic acid compositions

The total acid loss rate determination method comprises the following steps: loss rate (initial mass-mass after storage)/initial mass 100%

TABLE 1 evaluation results of content stability of respective acidifying agents

As can be seen from Table 1, the loss rate of the coated small organic acid compositions of examples 1 to 3 was within 0.28 after 7 days of packaging, was only within 0.42% even after 30 days of packaging, and was at a low level in all cases. The coated small-molecular organic acid composition of the comparative examples 1-2 has a loss rate of more than 4.0% at least and 4.56% at most after being packaged for 7 days, and a loss rate of 10.92% at most after being packaged for 30 days due to the removal of the chelating agent, the stabilizer or the adhesive, so that the loss rate of the comparative example 1 or the comparative example 2 is relatively serious under normal storage; comparative example 3 since the second coating layer was not included, the sample also had a serious loss rate of the small molecule organic acid.

Test example 2: simulated digestion test

To further verify the technical effect of the coated small molecule organic acid composition of the present invention, digestion tests of gastric and intestinal digestive juices were performed.

The test method comprises the following steps: the in vitro digestion simulation technology is a method for evaluating the digestion and absorption of the feed in vitro by simulating the digestion physiological characteristics of animals and adopting a digestion environment and a digestion enzyme system which are similar to those in the animal bodies, and the specific method refers to the research progress of the single-stomach animal in vitro digestion simulation technology [ J ] animal nutrition report, 2005(02):3-10. the results are shown in table 2.

TABLE 2 Release rates of the respective acidifying agents in simulated gastric and intestinal fluids

As can be seen from Table 2, the coated small-molecule organic acid compositions of examples 1 to 3 of the present invention released about 30% in gastric juice, and the release rate was low, whereas the acidifying agents of comparative examples 1 to 4 did not include a chelating agent, a stabilizer, a binder, or a second coating layer, and the coating layer was not included in comparative example 4, resulting in the low release of the acidifying agent in stomach, especially in comparative example 4, the release rate in gastric juice was as high as 98.25% without the coating layer, resulting in the large reduction of small-molecule organic acids that can reach the posterior intestinal tract, and failing to exert the original functions of the small-molecule organic acids. The coated small molecular organic acid composition prepared by the invention has the advantages that the small molecular organic acid can be well and slowly released in the rear intestinal tract, the bacteriostatic and bactericidal effects are achieved, and the intestinal health is better promoted.

Test example 3: animal experiments

In order to further verify the technical effect of the coated small molecular organic acid composition, the coated small molecular organic acid composition is used for animal application experiments.

The experimental diets are shown in table 3:

TABLE 3 basic daily ration

The experimental design is shown in table 4:

table 4 experimental design

The test method comprises the following steps: 192 healthy weaned piglets of consistent age in days (about 8.5 kg/head) were selected and randomized into 4 treatments, 4 replicates each, with 12 piglets per replicate. Each group was given the corresponding test ration according to the test design, the period was 21 days, and each group was weighed before and after the test.

Feeding management: the test pigsty daily management during the test was performed according to the normal program of the pigsty. Adopts a feeding method of free food intake and free water drinking. Keep the pigsty clean and sanitary and has good ventilation condition. The disease, death, etc. of piglets were observed and recorded regularly every day during the test period.

Measurement items:

1. growth performance

The feed intake of the test pigs, the number and weight of dead pigs were recorded daily, and the average daily gain, daily feed consumption, feed conversion ratio and death and culling rate at each stage during the test period were calculated.

Average daily feed intake ═ total feed added-trough remainder)/(column remainder number x total number of test days + number of dead pigs x number of test days)

Average daily gain (weight at end of column-initial weight at end of column + weight at end of dead pan pigs)/(number of remaining heads at column x total days of test + number of heads of dead pan pigs x days of test)

Feed/average daily gain

The mortality and elimination rate (total mortality and elimination multiplied by 100%)/total number of piglets per group

2. Rate of diarrhea

The diarrhea of the experimental piglets was recorded daily.

The diarrhea rate is the total number of diarrhea x 100%/(total number of trials x total number of days).

3. Appearance rating

The pig is observed and compared once a week, and can be divided into 4 grades of poor, medium, good and excellent according to the hair and color of the pig (the grades are respectively 1, 2, 3 and 4)

Data statistics and analysis

The experimental data were collated using Excel 2010, single factor analysis of variance using SPSS16.0 software, and significance of differences tested using the Dun-can method, with the results expressed as mean ± standard error, as shown in table 5.

Analysis of results

TABLE 5 Effect of different treatment groups on piglet growth Performance

Item	Treatment group 1	Treatment group 2	Treatment group 3	Treatment group 4
					Initial weight (kg)	8.35±0.01	8.32±0.01	8.31±0.00	8.33±0.01
Terminal weight (kg)	12.59±0.19	13.12±0.11	12.76±0.15	12.65±0.01
					Average daily food intake (g/d)	342.45±30.32	422.59±8.92	397.83±10.45	383.13±25.77
Average daily gain (g/d)	239.37±9.15	269.30±22.72	259.37±9.14	246.31±12.96
					Meat ratio of materials	1.56±0.07	1.37±0.02	1.53±0.08	1.46±0.02
Diarrhea Rate (%)	3.25±1.75	1.58±0.57	2.57±1.04	2.74±0.31
					Hair colour score	4.32±0.01	4.34±0.01	4.31±0.02	4.33±0.02
Eliminating number of heads	2	2	1	1

As can be seen from table 5, in the piglet diet, the average end weight, average feed intake and average daily gain of the piglets in the treatment group 2 were significantly higher than those in the treatment groups 1 and 4; from the aspect of feed conversion ratio, the feed conversion ratio of the piglets of the treatment group 2 is superior to that of the piglets of the control treatment group 1 and the treatment group 4; from the aspect of diarrhea rate, the diarrhea rate of the piglets of the treatment group 2 is lower; the appearance of the fur color of the piglets of each treatment group was not significantly different.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.