A rumen-protected nicotinic acid additive for preventing ketosis in dairy cows and its preparation method

Abstract

The present application relates to the technical field of prevention of ketosis in dairy cows, and specifically discloses a rumen-passing niacin additive for preventing ketosis in dairy cows and a preparation method thereof. The rumen-passing niacin additive comprises a coating and a core material, wherein the core material comprises niacin and an auxiliary material, wherein the auxiliary material comprises sodium ferric ethylenediaminetetraacetate; the preparation method comprises the following steps: uniformly mixing niacin and the auxiliary material in proportion, modulating with water, drying, and making core material particles; and coating the core material particles with a coating to obtain a rumen-passing niacin additive. The present application has the characteristics of providing rumen-passing niacin with a better effect on preventing ketosis in dairy cows, improving the effect of niacin on preventing ketosis in dairy cows, and increasing the income of the ranch.

Description

Technical Field

[0001] This application relates to the technical field of preventing ketosis in dairy cows. More specifically, it relates to a rumen-protected nicotinic acid additive for preventing ketosis in dairy cows and a preparation method thereof. Background Art

[0002] In recent years, the dairy farming industry in China has developed rapidly with an expanding scale. However, there are many problems in the breeding process. For example, ketosis in dairy cows is a metabolic disease of systemic dysfunction mainly caused by disorders in the metabolism of carbohydrates and volatile fatty acids in the body. Ketosis in dairy cows not only reduces the milk production and the quality of milk, but also affects the reproductive performance of dairy cows. Effectively preventing the occurrence of ketosis in dairy cows has become a key issue.

[0003] Some studies have shown that the addition of nicotinic acid has a good effect on preventing ketosis in dairy cows. However, ordinary nicotinic acid is largely degraded in the rumen of dairy cows, and the content that can be effectively absorbed is greatly reduced. How to further improve the effect of nicotinic acid in preventing ketosis in dairy cows is an urgent problem to be solved. Summary of the Invention

[0004] In order to further improve the effect of nicotinic acid in preventing ketosis in dairy cows and increase the income of pastures, this application provides a rumen-protected nicotinic acid additive for preventing ketosis in dairy cows and a preparation method thereof.

[0005] In the first aspect, this application provides a rumen-protected nicotinic acid additive for preventing ketosis in dairy cows, adopting the following technical solution:

[0006] A rumen-protected nicotinic acid additive for preventing ketosis in dairy cows includes a coating and a core material. The core material includes nicotinic acid and auxiliary materials. The auxiliary materials include sodium ferric ethylenediaminetetraacetate. The mass ratio of sodium ferric ethylenediaminetetraacetate to nicotinic acid added is 1:(20 - 40).

[0007] By adopting the above technical solution, the rumen-protected technology is used in this application. The nicotinic acid and auxiliary materials are protected by the coating, so that they will not be degraded in the rumen of ruminants, but will be degraded and absorbed after reaching the abomasum and small intestine with an acidic environment. As an active ingredient, nicotinic acid, on the one hand, is a precursor of coenzyme I (NAD+) and coenzyme II (NADP+). These two coenzymes play the role of hydrogen donors in the oxidative energy supply of animals, and can promote the complete oxidation of fatty acids in the liver, effectively avoiding the production of ketone bodies and the accumulation of fatty acids in the liver; on the other hand, rumen-protected nicotinic acid can promote the secretion of neuropeptides and orexin A, thereby increasing the feed intake of dry matter, inhibiting the mobilization of body fat in dairy cows, reducing the generation of non-esterified fatty acids NEFA in dairy cows from the source, and further reducing the production of ketone bodies and triglycerides, thus effectively preventing the occurrence of ketosis, increasing the milk production of dairy cows, reducing costs such as those of ranch veterinarians, and increasing the income of pastures.

[0008] The functions of sodium ferric ethylenediaminetetraacetate in this application mainly include the following two aspects:

[0009] On the one hand, as a cofactor of nicotinic acid, sodium ferric ethylenediaminetetraacetate can promote the complete oxidation of fatty acids by nicotinic acid. This may be because nicotinic acid and nicotinamide are absorbed by the small intestine, and nicotinic acid is converted into nicotinamide in the body. Nicotinamide in the body is combined with ribose, phosphate, adenine, etc. through several consecutive enzymatic reactions to form coenzyme I (NAD+) and coenzyme II (NADP+). Coenzyme I (NAD+) and coenzyme II (NADP+) play the role of hydrogen donors in the oxidative energy supply of animals, and can promote the complete oxidation of fatty acids in the liver. The addition of sodium ferric ethylenediaminetetraacetate has a certain impact on the conversion of nicotinic acid to nicotinamide, thus affecting the formation of coenzyme I (NAD+) and coenzyme II (NADP+), and further promoting the complete oxidation of fatty acids. Specifically, it may be that when the rumen bypass technology is used, sodium ferric ethylenediaminetetraacetate in the excipients hydrolyzes and releases ferric ions in the abomasum and small intestine environment with a pH of 2-3. Coupled with the oxidation of ferric ions, after partial carbon-nitrogen bonds in the ethylenediaminetetraacetic acid radical ions generated by hydrolysis are broken, a secondary amine structure is formed, and the hydrogen atoms of the secondary amine are replaced by acyl groups, and the N-acylation process occurs to obtain nicotinamide, thereby promoting the full conversion of nicotinic acid to nicotinamide, and further promoting the complete oxidation of fatty acids, achieving the effect of preventing ketosis in dairy cows.

[0010] On the other hand, the added sodium ferric ethylenediaminetetraacetate in this application also acts as a substance to promote the complete oxidation of fatty acids. It may be that the ferric ions released by the hydrolysis of sodium ferric ethylenediaminetetraacetate have a certain impact on the oxidation process, can promote the complete oxidation of fatty acids, further reduce the formation of ketones and promote the oxidation of ketones. Sodium ferric ethylenediaminetetraacetate is compounded with nicotinic acid, and the two work synergistically to have a better preventive and alleviating effect on ketosis in dairy cows.

[0011] In addition, since the formed anion-cation difference in the system can affect the number of free calcium in the system, and thus also has a certain effect on ketosis. In this application, sodium ferric ethylenediaminetetraacetate is selected, and combined with the control of the addition amount of sodium ferric ethylenediaminetetraacetate, it may be that the anion-cation difference formed by the hydrolysis of sodium ferric ethylenediaminetetraacetate is suitable, so that within this addition amount range, the preventive effect on ketosis is better.

[0012] In summary, in this application, sodium ferric ethylenediaminetetraacetate is selected as a cofactor of nicotinic acid, and the two work synergistically to greatly improve the promotion of the complete oxidation of fatty acids, effectively reducing the production of ketone bodies and the accumulation of fatty acids in the liver, obtaining rumen bypass nicotinic acid with a better preventive or alleviating effect on ketosis in dairy cows, and improving the income of the ranch.

[0013] Optionally, the adjuvant further includes one or both of riboflavin and L-carnitine, and the addition mass ratio of riboflavin and / or L-carnitine to nicotinic acid added is 1:(12 - 16).

[0014] By adopting the above technical solution, riboflavin and L-carnitine participate in the in-vivo oxidation-reduction process, affect the oxidation process of fatty acids, promote the complete oxidation of fatty acids, cause fatty acids to be completely oxidized into carbon dioxide and water, supply energy, relieve the negative energy balance of dairy cows, enhance the effect of nicotinic acid in promoting the oxidation and decomposition of fatty acids, thus achieving the effect of preventing ketosis in dairy cows, reducing the cost of the ranch, and increasing the income of the ranch.

[0015] Optionally, the adjuvant further includes a mixture of riboflavin and L-carnitine with a mass ratio of 1:(2 - 3).

[0016] By adopting the above technical solution, through the control of the addition amounts of riboflavin and L-carnitine, the two act synergistically to participate in the oxidation-reduction reaction of fat and fatty acids in the body, influence each other, and have a stronger promoting effect on the complete oxidation of fatty acids.

[0017] Optionally, the mass ratio of the coating to the core material is (40 - 60):(45 - 60).

[0018] By adopting the above technical solution, with the coating and core material in the above mass ratio, the thickness of the coating is adjusted, so that the degradation rate of the core material in the rumen is low, while the release rate in the abomasum and small intestine is high, having a good nicotinic acid supplementation effect and improving the utilization rate. Preventing the coating from being too thick, resulting in a corresponding decrease in the release rate of the core material in the abomasum and small intestine, and also affecting the flow rate of rumen chyme and the bypass effect. While a too thin coating cannot protect the core material, and it will be degraded by a large number of microorganisms in the rumen.

[0019] Optionally, the coating includes polyacrylic resin II and bypass fat powder with a mass ratio of 1:(2 - 3).

[0020] By adopting the above technical solution, the core material obtained by using polyacrylic resin II and bypass fat powder in the above ratio is used to coat nicotinic acid and the adjuvant. Compared with using a single coating material, the rumen degradation rate is lower, and it has a better protection effect on the core material. At this time, compared with other iron compounds, sodium ferric edetate has iron stably existing in the form of a complex, thus preventing free iron from polymerizing or coordinating with polyacrylic resin II, preventing polyacrylic resin II from consuming iron when added together with iron-containing compounds, and thus reducing the promoting effect of iron on the complete oxidation of fatty acids.

[0021] Optionally, the bypass fat powder is selected as palm fat powder.

[0022] Optionally, the adjuvant further includes starch, and the mass ratio of sodium iron edetate to starch added is 1:(15 - 20).

[0023] By adopting the above technical solution, the addition of starch has the effect of promoting the formation of core material particles and has little influence on effects such as ketosis prevention.

[0024] Second, this application provides a method for preparing a rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows, adopting the following technical solution:

[0025] A method for preparing a rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows includes the following steps:

[0026] Preparation of core material particles: Mix nicotinic acid and adjuvant evenly in proportion, modulate with water, granulate, and dry to obtain core material particles; Coating of nicotinic acid particles: Coating the core material particles with a coating to obtain a rumen - bypass nicotinic acid additive.

[0027] Preferably, the coating includes polyacrylic resin II and rumen - bypass fat powder with a mass ratio of 1:(2 - 3). The specific operation of the step of coating nicotinic acid particles is as follows: Dissolve polyacrylic resin II in ethanol to obtain a polyacrylic resin II solution, spray the polyacrylic resin II solution as an inner coating layer on the surface of the core material particles, and dry to obtain polyacrylic resin II - coated nicotinic acid particles;

[0028] Then spray the melted rumen - bypass fat powder as an outer coating layer onto the surface of the polyacrylic resin II - coated nicotinic acid particles and dry to obtain rumen - bypass nicotinic acid additive particles.

[0029] By adopting the above technical solution, when L - carnitine is contained in the core material, L - carnitine has hygroscopicity. Using polyacrylic resin II with good waterproof performance as the inner coating layer effectively solves the problem of L - carnitine hygroscopicity. Then continue to coat the surface of the polyacrylic resin II - coated nicotinic acid particles with rumen - bypass fat powder. Rumen - bypass fat powder is made from vegetable fat and is a commonly used high - energy feed raw material in ruminant production. It is safe, has good rumen - bypass effect, high small intestine digestibility, and good rumen - bypass coating effect. Using the compound of rumen - bypass fat powder and polyacrylic resin II as the coating material, the nicotinic acid particles are small and evenly coat the core material particles. Finally, the prepared rumen - bypass nicotinic acid particles are round and have good formability, and can be used as a dietary additive for ruminants such as dairy cows.

[0030] In summary, this application has the following beneficial effects:

[0031] 1. In this application, sodium iron ethylenediaminetetraacetate is used as an auxiliary material for nicotinic acid. On the one hand, it affects the oxidation of fatty acids, promotes the complete oxidation of fatty acids, and alleviates the negative energy balance of dairy cows. On the other hand, it affects the transformation of nicotinic acid and nicotinamide, as well as the formation of coenzyme I (NAD+) and coenzyme II (NADP+), thereby enhancing the complete oxidation of fatty acids by nicotinic acid. The two work synergistically to enhance the effect of preventing ketosis in dairy cows, reduce the cost of the ranch, and increase the income of the ranch;

[0032] 2. With the addition of sodium iron ethylenediaminetetraacetate in this application, iron exists stably in the form of a complex, which can prevent the polymerization or coordination of free iron with polyacrylic resin II, and prevent polyacrylic resin II from consuming iron when added together with iron-containing compounds, thereby reducing the promoting effect of iron on the complete oxidation of fatty acids;

[0033] 3. In this application, polyacrylic resin II and rumen-protected fat powder are used as coating materials. Polyacrylic resin II with good waterproof performance is used as the inner coating layer, which can effectively solve the problem of the hygroscopicity of L-carnitine. Rumen-protected fat powder as the outer coating layer has a better rumen-protected effect. Using the compound of rumen-protected fat powder and polyacrylic resin II as the coating material, the nicotinic acid particles are small and evenly coated as the core particles. Finally, the prepared rumen-protected nicotinic acid particles are round and well-shaped, and can be added to the diet of ruminants such as dairy cows. Detailed implementation mode

[0034] The following further elaborates on this application in combination with examples. It should be specifically noted that: for those not indicating specific conditions in the following examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. Except for special instructions, the raw materials used in the following examples can all be obtained from ordinary commercial sources.

[0035] The rumen-protected nicotinic acid additive in this application can be prepared by conventional rumen-protected technology methods in the art. Preferably, considering that L-carnitine has hygroscopicity, polyacrylic resin II is selected as the inner coating layer and rumen-protected fat powder as the outer coating layer in this application. The specific coating process can adopt conventional methods in the art. The rumen-protected nicotinic acid additive in this application can specifically include the following steps:

[0036] Preparation of core particles: Mix nicotinic acid and auxiliary materials evenly in proportion, modulate with water, then granulate in a granulator, and then perform shot blasting and drying to obtain core particles with a size of 0.3 - 0.5 mm;

[0037] Coating of nicotinic acid particles: Dissolve polyacrylic resin II in ethanol to obtain a polyacrylic resin II solution. The mass ratio of polyacrylic resin II to ethanol is 1:2. Spray the polyacrylic resin II solution as the inner coating layer on the surface of the core particles. The spraying process is carried out in a fluidized granulation coating machine to obtain polyacrylic resin II-coated nicotinic acid particles;

[0038] Then, the molten protected rumen fat powder is sprayed onto the surface of the polyacrylic resin II-coated nicotinic acid granules as an outer coating layer. This process is carried out using a fluidized granulation and coating machine for coating, followed by drying and screening to obtain protected rumen nicotinic acid additive granules with a particle size of 0.8 - 1.2 mm.

[0039] In the coating step, the spraying parameters of the polyacrylic resin II solution and the molten protected rumen fat powder can be: compressed air temperature of 90 °C, peristaltic pump speed of 8 rpm, induced air frequency of 28 Hz, rotation speed of 50 Hz, induced air temperature of 45 °C, and outlet air temperature of 40 °C.

[0040] In the following examples, polyacrylic resin II can be purchased from Shanxi Jinyang Pharmaceutical Excipients Co., Ltd., with a superior grade, model cp2015, and brand Jinyang Excipients;

[0041] Riboflavin can be purchased from Nanjing Ximeinuo Biotechnology Co., Ltd., with a food-grade model and in powder form;

[0042] L-carnitine can be purchased from Nanjing Tongying Biotechnology Co., Ltd., with the brand Tongying and a food-grade model;

[0043] The palm fat powder can be the palm fat powder purchased from Henan Noah Biotechnology Co., Ltd., with the brand Yihai.

[0044] Example 1

[0045] A preparation method of a protected rumen nicotinic acid additive for preventing ketosis in dairy cows includes the following steps:

[0046] Preparation of core material particles: The raw materials of the core material particles include nicotinic acid and excipients. The excipients include sodium ferric edetate and starch. Specifically, nicotinic acid, sodium ferric edetate, and starch are taken as the core material. Nicotinic acid, sodium ferric edetate, and starch are mixed evenly, modulated with water, and then granulated, polished, and dried in sequence to obtain core material particles. The addition amount of nicotinic acid is 20 kg, the mass ratio of nicotinic acid to sodium ferric edetate is 20:1, and the added mass ratio of sodium ferric edetate to starch is 1:15;

[0047] Coating of nicotinic acid granules: Polyacrylic resin II and protected rumen fat powder with a mass ratio of 1:2 are used as the coating. The mass ratio of the coating to the core material is 40:60, that is, the mass ratio of the sum of polyacrylic resin II and protected rumen fat powder to the sum of nicotinic acid, starch, and sodium ferric edetate is 40:60. The core material is coated with the coating through a fluidized granulation and coating machine. The specific operation is as follows:

[0048] Dissolve polyacrylic resin II in ethanol to obtain a polyacrylic resin II solution, where the mass ratio of polyacrylic resin II to ethanol is 1:2. Spray the polyacrylic resin II solution as the inner coating layer on the surface of the core material particles. The spraying process is carried out in a fluidized granulation coating machine to obtain polyacrylic resin II-coated nicotinic acid particles.

[0049] Then spray the molten protected fat powder as the outer coating layer onto the surface of the polyacrylic resin II-coated nicotinic acid particles. This process is carried out using a fluidized granulation coating machine for coating, followed by drying and screening to obtain protected nicotinic acid additive particles with a particle size of 0.8 - 1.2 mm.

[0050] In the step of coating the nicotinic acid particles: the mass ratio of polyacrylic resin II to protected fat powder is 1:2.

[0051] Example 2

[0052] A preparation method of a protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 1, with the difference that the added mass ratio of nicotinic acid to sodium ferric ethylenediaminetetraacetate in the core material is 30:1, and the added mass ratio of sodium ferric ethylenediaminetetraacetate to starch is 1:17; in the coating, the mass ratio of polyacrylic resin II to protected fat powder is 1:2.5, and the mass ratio of the coating to the core material is 50:50.

[0053] Example 3

[0054] A preparation method of a protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 1, with the difference that the added mass ratio of nicotinic acid to sodium ferric ethylenediaminetetraacetate in the core material is 40:1, and the added mass ratio of sodium ferric ethylenediaminetetraacetate to starch is 1:20; in the coating, the mass ratio of polyacrylic resin II to protected fat powder is 1:3, and the mass ratio of the coating to the core material is 60:45.

[0055] Example 4

[0056] A preparation method of a protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that the added mass ratio of nicotinic acid to sodium ferric ethylenediaminetetraacetate in the core material is 20:1.

[0057] Example 5

[0058] A preparation method of a protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that the added mass ratio of nicotinic acid to sodium ferric ethylenediaminetetraacetate in the core material is 40:1.

[0059] Example 6

[0060] A preparation method of a rumen - protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that

[0061] In the preparation step of the core - material particles: the coating also includes riboflavin and L - carnitine with a mass ratio of 1:2, and the sum of the addition amounts of riboflavin and L - carnitine and the added mass ratio of nicotinic acid is 1:12. Riboflavin and L - carnitine are added together with nicotinic acid and sodium ferric ethylenediaminetetraacetate. The mass ratio of the coating to the core material is 50:50, that is, the sum of polyacrylic resin II and rumen - protected fat powder and the sum of nicotinic acid, sodium ferric ethylenediaminetetraacetate, riboflavin, L - carnitine, and starch have a mass ratio of 50:50.

[0062] Example 7

[0063] A preparation method of a rumen - protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that

[0064] In the preparation step of the core - material particles: the coating also includes riboflavin and L - carnitine with a mass ratio of 1:3, and the sum of the addition amounts of riboflavin and L - carnitine and the added mass ratio of nicotinic acid is 1:16. Riboflavin and L - carnitine are added together with nicotinic acid and sodium ferric ethylenediaminetetraacetate. The mass ratio of the coating to the core material is 50:50, that is, the sum of polyacrylic resin II and rumen - protected fat powder and the sum of nicotinic acid, sodium ferric ethylenediaminetetraacetate, riboflavin, L - carnitine, and starch have a mass ratio of 50:50.

[0065] Example 8

[0066] A preparation method of a rumen - protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 6, with the difference that

[0067] In the preparation step of the core - material particles, riboflavin is replaced equally with L - carnitine, and the added mass ratio of L - carnitine to nicotinic acid is 1:12.

[0068] Example 9

[0069] A preparation method of a rumen - protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 8, with the difference that in the preparation step of the core - material particles, L - carnitine is replaced equally with riboflavin, and the added mass ratio of riboflavin to nicotinic acid is 1:12.

[0070] Example 10

[0071] A preparation method of a rumen - protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that in the nicotinic acid particle coating step, polyacrylic resin II in the coating is replaced equally with rumen - protected fat powder, and the coating material of the core - material particles is a single - layer coating of rumen - protected fat powder.

[0072] Example 11

[0073] A preparation method of a rumen - protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 2. The difference is that in the step of coating nicotinic acid particles, the rumen - protected fat powder in the coating is replaced with polyacrylic resin II in equal amount, and the coating material of the core particles is a single - layer coating of polyacrylic resin II.

[0074] Example 12

[0075] A preparation method of a rumen - protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 6. The difference is that in the step of coating nicotinic acid particles, the polyacrylic resin II in the coating is replaced with rumen - protected fat powder in equal amount, and the coating material of the core particles is a single - layer coating of rumen - protected fat powder.

[0076] Example 13

[0077] A preparation method of a rumen - protected nicotinic acid additive for preventing ketosis in dairy cows is carried out according to the method in Example 6. The difference is that in the step of coating nicotinic acid particles, the rumen - protected fat powder in the coating is replaced with polyacrylic resin II in equal amount, and the coating material of the core particles is a single - layer coating of polyacrylic resin II.

[0078] Control Example

[0079] Control Example 1

[0080] A preparation method of a rumen - protected additive for preventing ketosis in dairy cows is carried out according to the method in Example 2. The difference is that in the core material, sodium ferric ethylenediaminetetraacetate is not added, and only nicotinic acid is added.

[0081] Control Example 2

[0082] A preparation method of a rumen - protected additive for preventing ketosis in dairy cows is carried out according to the method in Example 2. The difference is that in the core material, nicotinic acid is not added, and only sodium ferric ethylenediaminetetraacetate is added.

[0083] Control Example 3

[0084] A preparation method of a rumen - protected additive for preventing ketosis in dairy cows is carried out according to the method in Example 2. The difference is that sodium ferric ethylenediaminetetraacetate is replaced with nicotinic acid in equal amount.

[0085] Control Example 4

[0086] A preparation method of a rumen - protected additive for preventing ketosis in dairy cows is carried out according to the method in Example 2. The difference is that nicotinic acid is replaced with sodium ferric ethylenediaminetetraacetate in equal amount.

[0087] Control Example 5

[0088] A preparation method of a rumen - bypass additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that the mass ratio of nicotinic acid to sodium ferric ethylenediaminetetraacetate is 18:1.

[0089] Comparative Example 6

[0090] A preparation method of a rumen - bypass additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that the mass ratio of nicotinic acid to sodium ferric ethylenediaminetetraacetate is 43:1.

[0091] Comparative Example 7

[0092] A preparation method of a rumen - bypass additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that sodium ferric ethylenediaminetetraacetate is replaced with ferric chloride in equal amount.

[0093] Comparative Example 8

[0094] A preparation method of a rumen - bypass additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that sodium ferric ethylenediaminetetraacetate is replaced with ferrous sulfate in equal amount.

[0095] Comparative Example 9

[0096] A preparation method of a rumen - bypass additive for preventing ketosis in dairy cows is carried out according to the method in Example 2, with the difference that sodium ferric ethylenediaminetetraacetate is replaced with ferrous lactate in equal amount.

[0097] Performance detection

[0098] 1. Detection of rumen - bypass effect of rumen - bypass nicotinic acid additive

[0099] Considering that the rumen - bypass effect of the rumen - bypass nicotinic acid additive is mainly related to the coating material and the quality of the coating and core materials, therefore, in this application, the rumen - bypass effect performance of the rumen - bypass nicotinic acid additives prepared in Examples 1 - 3 and Examples 10 - 13 is mainly evaluated. Specifically:

[0100] Taking Holstein lactating dairy cows as experimental objects, the rumen - bypass nicotinic acid additives prepared in Examples 1 - 3 and Examples 10 - 13 are used as the experimental groups, and the uncoated nicotinic acid additive in Example 2 (that is, the nicotinic acid core - material particles in Example 2) is used as the control group. The rumen degradation rates of the additives in the experimental groups and the control group of this application are measured at 4 culture points of 2h, 8h, 12h, and 24h by the rumen nylon - bag method. Four parallel tests are carried out for each experimental group and the control group, and the test results are shown in Table 1 below. The data in Table 1 are the average values of four repeated experiments.

[0101] Table 1 Degradation rate of rumen - bypass nicotinic acid additive (%)

[0102]

[0103] As can be seen from Table 1 above, more than 95% of the nicotinic acid without coating treatment in this application is degraded. However, the degradation rate of the rumen-protected nicotinic acid after coating treatment in the examples is reduced to 5-15% after 12 hours of incubation in the rumen, less than 20% after 24 hours of incubation, and less than 10% after 2 hours of incubation, greatly reducing its degradation rate. In particular, the degradation rates of the rumen-protected nicotinic acid in Example 2 after 12 hours and 24 hours of incubation in the rumen are 5.64% and 7.98% respectively, with a low degradation rate, greatly improving the rumen bypass rate. In addition, referring to the test results of Example 2 and Examples 11 and 12, it can be seen that the degradation rate of the compound of polyacrylic resin II and rumen-protected fat powder selected in this application in the rumen is much lower than that of their single use.

[0104] 2. Effects of Rumen-Protected Nicotinic Acid Additive on the Production Performance of Lactating Cows

[0105] Test method:

[0106] Select Holstein cows with similar postpartum days (5-10 days), age, parity, body condition, and milk production as experimental cows, with 8 cows in each group. One group is the control group, fed a basal diet, and the remaining groups are experimental groups. Each experimental cow is added with the rumen-protected nicotinic acid additive prepared in the examples and comparative examples at a dose of 20 g per cow per day. The experimental cows are fed in single stalls, fed 3 times a day (morning, noon, and evening), and milked 3 times. The rumen-protected nicotinic acid is mixed in the concentrate. The experimental period is 30 days.

[0107] Test performance

[0108] 1) Determination of β-hydroxybutyric acid (BHBA)

[0109] Feed the experimental cows according to the above test method. The experimental cows are bled from the caudal vein before morning feeding on the day before the experiment, the 5th day, and the 10th day, and the content of BHBA (mmol·L -1 ) is detected with a blood ketone meter. The test results of the examples and comparative examples are shown in Table 2 below, and the test results of the control group are shown in Table 3 below.

[0110] Table 2 Effects of Rumen-Protected Nicotinic Acid Additive in the Experimental Group on the Content of BHBA in the Plasma of Lactating Cows

[0111]

[0112] Table 3 Effects of the Control Group on the Content of BHBA in the Plasma of Lactating Cows

[0113]

[0114] Referring to the test results in Table 3 above, it can be seen that when lactating dairy cows are fed only the basic diet, the BHBA content shows an upward trend after feeding; referring to the test results in the embodiment in Table 2 above, the BHBA content in the test group shows a downward trend after feeding rumen-transfected niacin, and the feeding of rumen-transfected niacin has a positive effect on preventing ketosis in dairy cows.

[0115] Referring to the test results of Example 2, Example 4 and Example 5 and Comparative Example 5 and Comparative Example 6, it can be seen that by changing the ratio of nicotinic acid and sodium ferric ethylenediaminetetraacetate, as the proportion of sodium ferric ethylenediaminetetraacetate increases, the BHBA concentration first decreases significantly, and then decreases slightly. When the amount of sodium ferric ethylenediaminetetraacetate added is too low, the BHBA change is small, and when the amount of sodium ferric ethylenediaminetetraacetate added is too large, its concentration increases instead. The effect of sodium ferric ethylenediaminetetraacetate on the prevention of ketosis is first significantly enhanced and then decreased. This may be because when the amount of sodium ferric ethylenediaminetetraacetate added is too low, its oxidation effect and auxiliary promotion effect on nicotinic acid are small, and when the amount added is too large, on the one hand, the conversion of nicotinic acid and nicotinamide leads to the formation of coenzyme I (NAD+) and coenzyme II (NADP+), and its effect is reduced. On the other hand, when the content is too large, the difference between anions and cations in the system is not within an appropriate range, and its effect is reduced.

[0116] Referring to the test results of Comparative Examples 1 and 2 and the control group, it can be seen that the addition of nicotinic acid and sodium ferric ethylenediaminetetraacetate can reduce the BHBA content. Combining the test results of Comparative Examples 4 and 5 and Example 2, it can be seen that when sodium ferric ethylenediaminetetraacetate and nicotinic acid are compounded in a specific ratio, a synergistic effect is achieved, the BHBA content is reduced, and the preventive effect on ketosis in dairy cows is greatly improved. Referring to the test results of Example 2 and Comparative Examples 7-9, it can be seen that when nicotinic acid is compounded with other iron salts, although there is an effect of reducing the BHBA content, the effect is small and far lower than the effect of the embodiment.

[0117] Combined with the test results of Examples 10-11 and Example 2, it can be seen that when only polyacrylic acid resin II or rumen bypass fat powder is used as the coating material, the effect of preventing dairy cow ketosis is low, possibly due to poor rumen bypass effect.

[0118] Referring to the test results of Examples 6-9, it can be seen that the addition of riboflavin and L-carnitine can further reduce the BHBA content and further enhance the effect of preventing ketosis in dairy cows.

[0119] 1. Dry matter intake

[0120] The measurement was carried out according to the above measurement method. Taking the test group fed with the rumen-protected nicotinic acid additive prepared in Example 2 as an example, the daily feed intake and the remaining feed amount after feeding of the test group and the control group in Example 2 were accurately recorded every day, and the dry matter intake of each test cow per day was calculated. The test results are shown in Table 4 below.

[0121] Table 4 Effects of rumen-protected nicotinic acid additive on dry matter intake of lactating dairy cows

[0122] Test items Example 2 Control group Dry matter intake (kg / head·day) 15.24 13.04

[0123] As can be seen from Table 4 above, after the test cows were fed with the rumen-protected nicotinic acid additive prepared in Example 2 of the present application, their dry matter intake increased by 16.87% compared with the control group. The rumen-protected nicotinic acid additive helps to increase the dry matter intake of dairy cows and has the effect of preventing ketosis in dairy cows at the source.

[0124] In addition, the dry matter intake of other test groups was detected according to the above method. It can be seen that after feeding with the rumen-protected nicotinic acid additive prepared in the examples of the present application, the dry matter intake increased by 10.2 - 17.5% compared with the control group. It can be seen that the rumen-protected nicotinic acid additive helps to increase the dry matter intake of dairy cows.

[0125] 2. Measurement of milk yield

[0126] The milk yield was measured according to the above-mentioned feeding and measurement method. Taking the test group fed with the rumen-protected nicotinic acid additive prepared in Example 2 as an example, the milk yields of the test dairy cows were recorded before the test, on the 10th day and on the 30th day, and the milk yields of the test cows in Example 2 were obtained. The test results are shown in Table 5 below.

[0127] Table 5 Effects of rumen-protected nicotinic acid additive on milk yield of lactating dairy cows

[0128] Test items Before the test On the 10th day On the 30th day Milk yield of Example 2 (kg·d-1) 24.35 27.32 31.78 Milk yield of the control group (kg·d-1) 24.29 24.67 27.42

[0129] As can be seen from Table 5 above, after the test cows were fed with the rumen-protected nicotinic acid additive prepared in Example 2 of the present application, the milk yield of the test cows on the 30th day increased by 15.90% compared with the control group. The addition of the rumen-protected nicotinic acid additive helps the milk yield of dairy cows.

[0130] In addition, the milk yield of other test groups was detected according to the above method. It can be seen that after feeding with the rumen-protected nicotinic acid additive prepared in the examples of the present application, the milk yield increased by 10.5 - 16.7% compared with the control group. It can be seen that the rumen-protected nicotinic acid additive helps to increase the milk yield of dairy cows.

[0131] In summary, it can be seen that adding the rumen - protected nicotinic acid additive obtained in the present application to the dairy cow diet can effectively prevent the occurrence of ketosis in dairy cows, while significantly increasing the feed intake and milk yield of dairy cows, and greatly improving the economic benefits of the ranch.

[0132] This specific embodiment is only an explanation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows, comprising a coating and a core material, characterized in that, the core material comprises nicotinic acid and auxiliary materials, the auxiliary materials include sodium ferric ethylenediaminetetraacetate, and the mass ratio of sodium ferric ethylenediaminetetraacetate to nicotinic acid added is 1:(20 - 40); the auxiliary materials further comprise at least L - carnitine; the coating comprises polyacrylic resin II and rumen - bypass fat powder with a mass ratio of 1:(2 - 3). The rumen - bypass fat powder is selected as palm fat powder, and polyacrylic resin II serves as the inner coating layer while the rumen - bypass fat powder serves as the outer coating layer.

2. The rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows according to claim 1, characterized in that: the auxiliary materials further comprise one or both of riboflavin and L - carnitine, and the addition amount of riboflavin and / or L - carnitine to the added mass of nicotinic acid is 1:(12 - 16).

3. The rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows according to claim 1, characterized in that: the auxiliary materials further comprise a mixture of riboflavin and L - carnitine with a mass ratio of 1:(2 - 3).

4. The rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows according to claim 1, characterized in that: the mass ratio of the coating to the core material is (40 - 60):(45 - 60).

5. The rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows according to claim 1, characterized in that: the auxiliary materials further comprise starch, and the mass ratio of sodium ferric ethylenediaminetetraacetate to starch added is 1:(15 - 20).

6. A preparation method of the rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows as claimed in claim 1, comprising the following steps: Preparation of core material particles: Mix nicotinic acid and auxiliary materials evenly according to the ratio, modulate with water, granulate, and dry to obtain core material particles; Coating of nicotinic acid particles: Coat the core material particles with a coating to obtain the rumen - bypass nicotinic acid additive.

7. The preparation method of the rumen - bypass nicotinic acid additive for preventing ketosis in dairy cows according to claim 6, characterized in that: the coating comprises polyacrylic resin II and rumen - bypass fat powder with a mass ratio of 1:(2 - 3). The specific operation of the nicotinic acid particle coating step is: Dissolve polyacrylic resin II in ethanol to obtain a polyacrylic resin II solution, spray the polyacrylic resin II solution as the inner coating layer on the surface of the core material particles, and dry to obtain polyacrylic resin II - coated nicotinic acid particles; Then spray the melted rumen - bypass fat powder as the outer coating layer onto the surface of the polyacrylic resin II - coated nicotinic acid particles, and dry to obtain rumen - bypass nicotinic acid additive particles.

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