Feed additive, feed, feeding method, selenium-enriched cow milk and obtaining method

Abstract

The invention discloses a feed additive, feed, a feeding method and a selenium-enriched cow milk obtaining method. The feed additive comprises a core material and a coating film, the core material comprises a carrier and organic selenium, and the coating at least comprises a material which is stable in a rumen environment and has a swelling effect in a small intestine; the selenium content in the feed additive is 0.6 to 1.5 g / kg. According to the invention, cow milk with higher selenium content can be obtained under the condition that a smaller amount of organic selenium is added, the selenium content in the cow milk can be increased to 9ug / 100g or above, and the absorption and utilization rate of the organic selenium is remarkably increased.

Description

Technical Field

[0001] The invention relates to the field of milk, and in particular to a feed additive, a feed, a feeding method and a method for obtaining selenium-enriched cow's milk. Background Art

[0002] Milk is rich in various nutrients and can provide some of the nutrients needed by the human body in daily life, such as protein and calcium. However, with the increasing incidence of sub-health, the nutritional components in cow's milk cannot meet the needs of the human body, especially selenium. Selenium is a trace element in animals with strong antioxidant properties and can enhance the body's immunity.

[0003] At present, the method of increasing selenium in milk includes directly adding selenium-containing ingredients to milk. The stability and taste of milk produced by this method are affected by additives, and it does not conform to the consumption trend of pure natural and additive-free. Another method of adding selenium is to add selenium-containing raw materials to the feed of dairy cows, which is converted into natural milk selenium through milk metabolism, thereby increasing the selenium content in milk.

[0004] Among the existing feeding methods, organic selenium is usually added directly to the feed, for example, in a selenium-enriched feed composition for dairy cows and its application disclosed in Chinese patent application document CN112868917A, 15 parts of organic selenium source in terms of selenium are added to 100 parts of basic feed. Alternatively, the selenium content of milk can be increased by feeding selenium-enriched raw materials such as high-selenium corn powder and high-selenium broccoli powder, for example, in a feeding method for increasing the selenium content in milk disclosed in Chinese patent application document CN114431186A, a selenium-enriched feed additive for dairy cows and a method for producing selenium-enriched milk disclosed in CN111972555A, etc.; furthermore, the selenium content can be increased by feeding yeast selenium, for example, in a selenium-enriched feed additive for dairy cows and a method for producing selenium-enriched milk disclosed in CN111972555A, etc.

[0005] The above methods all have the problem of relatively high cost and low conversion rate of selenium from feed to milk. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is that the conversion rate of selenium in the prior art is low; thus, a feed additive, a feed, a feeding method and a method for obtaining selenium-enriched milk are provided.

[0007] To this end, the present invention provides the following technical solutions:

[0008] A feed additive, comprising a core material and a coating;

[0009] The core material includes a carrier and organic selenium, and the envelope at least includes a material that is stable in the rumen environment and has a swelling effect in the small intestine;

[0010] The selenium content in the feed additive is 0.6-1.5 g / kg.

[0011] The carrier is at least one of starch, β-cyclodextrin, hydroxypropyl methylcellulose, chitosan, sodium alginate, and silicon dioxide;

[0012] And / or, the coating is at least one of glyceryl monostearate, glyceryl monolaurate, carnauba wax, palm oil, polyacrylic acid resin and ethyl cellulose. When the coating is at least one of glyceryl monostearate, glyceryl monolaurate, carnauba wax, palm oil and ethyl cellulose, an outer film is further provided on the coating, and the outer film is polyacrylic acid resin;

[0013] And / or, the organic selenium is at least one of methionine selenium and homolanine selenium.

[0014] The mass ratio of the sum of the mass of the envelope and the core material to the mass of the outer film is 1:(0.6-0.8);

[0015] And / or, the outer layer film is polyacrylic acid resin II and / or polyacrylic acid resin III; preferably, when the outer layer film is polyacrylic acid resin II and polyacrylic acid resin III, the mass ratio of polyacrylic acid resin II to polyacrylic acid resin III is (0.6-1): (2-3.3).

[0016] The weight ratio of the organic selenium to the carrier is 1:0.5-0.8, preferably 1:0.7;

[0017] And / or, the mass ratio of the coating to the core material is (0.15-0.60):10, preferably (0.3-0.6):10.

[0018] The core material further comprises at least one of fucoidan, corn protein powder hydrolyzate and an emulsifier;

[0019] Preferably, the corn gluten powder hydrolysate is a supernatant obtained by centrifuging a corn gluten powder aqueous solution after protease hydrolysis and enzyme inactivation; and / or, the emulsifier is phospholipid;

[0020] Preferably, the mass ratio of the organic selenium to fucoidan is 1:(0.02-0.08); and / or, the added amount of the corn protein powder hydrolyzate solution is 2-4 times that of the organic selenium; and / or, the mass of the emulsifier is 0.3% of the total weight of the carrier and the organic selenium.

[0021] The preparation process of the corn protein powder hydrolyzate is as follows:

[0022] Weigh corn gluten powder, add water and mix well, adjust the substrate concentration to 6-10g / 100mL, adjust the pH to 10-12 with sodium hydroxide, stir well for 10-15min at 60°C, and then stand for hydration to obtain a hydrolysis substrate; adjust the pH to the reaction pH of protease with an acid-base regulator, add 2200-4000U / g of protease, perform enzymolysis at 50-60°C, and after enzymolysis for 2-4h, heat to 85°C to inactivate the enzyme for 10-15min; centrifuge to obtain a supernatant, which is the corn gluten powder hydrolyzate, the centrifugation parameter is 4500-5000r / min, the centrifugation is 15-25min, and the soluble solid concentration in the supernatant is 30mg / kg;

[0023] The protease includes at least one of alkaline protease, neutral protease, trypsin and papain.

[0024] A preparation process of a feed additive, comprising:

[0025] Preparation of core material: the carrier and organic selenium are mixed in a solvent, and after homogenization, they are dried, crushed, and granulated to obtain core material particles. Preferably, the homogenization conditions are 40-50°C, 160-180 bar, and the drying temperature is 70-90°C; or, after mixing the organic selenium with the solvent, they are sprayed onto the carrier that is boiling and expanding under high temperature conditions, and the core material particles are prepared after drying and low-temperature curing. Preferably, the temperature of the high temperature condition is 220-240°C, the drying temperature is 110-120°C, and the low-temperature curing temperature is -10--15°C;

[0026] Preparation of the coating: Mix the coating with an organic solvent to prepare an embedding layer solution. Preferably, the mass ratio of the coating to the organic solvent is 1:(5-10). Then, the core material particles are coated with the embedding layer solution. Preferably, the mass ratio of the core material particles to the embedding layer solution is 10:(2-4).

[0027] The parameters when the embedding layer solution is used to coat the core material particles are: embedding layer solution flow rate 0.05-3.5 L / min, air inlet temperature 45-85°C, air outlet temperature 20-30°C, time 3-4h;

[0028] And / or, in the preparation of the core material, the solvent is water and / or corn protein powder hydrolyzate.

[0029] A feed comprising the above feed additive.

[0030] The feed additive is added in an amount of 0.02 to 0.10%;

[0031] Preferably, the feed comprises feed additives, concentrated feed and roughage in a mass ratio of (0.03-0.06):(15-25):(45-60);

[0032] More preferably, the concentrate feed comprises at least one of rumen bypass choline, rumen bypass glucose, rumen bypass lysine, yeast powder, vitamins, minerals, corn flour, and soybean meal; preferably, the vitamins comprise at least one of vitamin D3, vitamin K3, vitamin B1, vitamin B2, vitamin B6, folic acid, pantothenic acid, and niacin; and / or, the mineral elements comprise at least one of copper, iron, manganese, zinc, and iodine;

[0033] More preferably, the roughage includes at least one of silage corn, oat hay, alfalfa hay and forage grass.

[0034] A method for obtaining selenium-enriched cow milk is disclosed, which comprises feeding the above-mentioned feed continuously for 15 to 45 days to obtain selenium-enriched cow milk with a lactation period of 10 to 210 days.

[0035] A method for processing selenium-enriched cow's milk, comprising the steps of obtaining milk obtained by the above-mentioned obtaining method, and subjecting the milk to the steps of milk purification, impurity removal, microfiltration and sterilization, concentration and sterilization;

[0036] The selenium content in the milk after the processing step reaches above 9ug / 100g.

[0037] A selenium-enriched milk is prepared by adopting the above-mentioned obtaining method or the above-mentioned processing method.

[0038] The technical solution of the present invention has the following advantages:

[0039] 1. The feed additive provided by the present invention adopts organic selenium as raw material, and the organic selenium and other carrier components are combined to form a core material, and then the organic selenium is embedded with a coating material. At the same time, a coating material that is stable in the rumen environment and has a swelling effect in the small intestine is selected, so that the coating can pass through the rumen and release the organic selenium in the small intestine, thereby improving the absorption and utilization rate of selenium. With the addition of a smaller amount of organic selenium, cow's milk with a higher selenium content can be obtained, and the selenium content in the cow's milk can be increased to more than 9ug / 100g, which significantly improves the absorption and utilization rate of organic selenium.

[0040] 2. In view of the properties of organic selenium, the present invention preferably adds antioxidants, antibacterial substances, and substances that promote selenium absorption into the carrier to further improve the embedding effect and the absorption and utilization rate of selenium.

[0041] 3. The invention preferably uses a double-layer coating to coat the core material. Feed additives embedded with organic selenium are added to feed for feeding experiments. It is known that the double-layer coating can further improve the absorption and utilization rate of selenium; the selenium content is increased to more than 12ug / 100g.

[0042] 4. In the steps of microfiltration membrane sterilization, membrane concentration, and steam direct sterilization of the selenium-containing fresh milk provided by the present invention, the selenium content can be further increased by membrane concentration, while the degree of heat during the processing can be reduced to maintain the flavor and taste of the product.

[0043] 5. The selenium-enriched milk provided by the present invention has been verified through mouse experiments and found that the selenium-enriched milk of the present invention can effectively improve immunity and antioxidant performance, and the effect is remarkable. DETAILED DESCRIPTION

[0044] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0045] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0046] The process of obtaining corn protein meal hydrolyzate is as follows:

[0047] ① Weigh a certain amount of corn gluten powder, add a certain proportion of water and mix well, adjust the substrate concentration to 8g / 100mL, adjust the pH to 11 with sodium hydroxide, stir well for 12min at 60℃ and let stand for 30min. ② Use an acid-base regulator to adjust the pH to the reaction pH of each protease, add 3000U / g protease, and perform enzymatic hydrolysis at 55℃. The protease is alkaline protease. After hydrolysis for 3h, heat to 85℃ and inactivate the enzyme for 13min. ③ Centrifuge in a centrifuge to obtain the supernatant, which is the corn gluten powder hydrolyzate. The centrifugation parameters are 48000r / min, centrifugation for 20min, and the soluble solid concentration of the obtained solution is 30mg / kg.

[0048] The selenium content of methionine selenium is 2000mg / kg.

[0049] The selenium content of homolanine selenium is 4000mg / kg.

[0050] Embodiment 1:

[0051] 1. Preparation of feed additives:

[0052] ① β-cyclodextrin, methionine selenium and fucoidan were mixed evenly in a mass ratio of 0.7:1:0.05. That is, 70 kg of β-cyclodextrin, 100 kg of methionine selenium and 5 kg of fucoidan were mixed evenly to obtain a mixture, which was mixed with 300 kg of corn protein powder hydrolysate as the core material (the solid content of corn protein powder hydrolysate was 30 mg / kg), and 0.51 kg of phospholipid was added. The mixture was passed through a homogenizer at 45°C and 170 bar, and then dried at 80°C, crushed and granulated to obtain core material particles.

[0053] ② Weigh ethyl cellulose in a mass ratio of 1:9 and mix and dissolve in 95% ethanol solution. Stir and dissolve at 150 rpm / min to prepare the embedding layer solution.

[0054] ③ According to the mass ratio of ethyl cellulose content in the embedding layer solution to the core material of 0.3:10, weigh the core material particles and the embedding layer solution, mix them and send them into the coating equipment at a flow rate of 2L / min and an inlet air temperature of 65℃ for embedding to obtain single-layer coated particles.

[0055] ④ Weigh the single-layer coated particles and the outer layer membrane material in a mass ratio of 1:0.7, wherein the outer layer membrane material is polyacrylic resin II (Polyacrylic Resin II) that meets pharmaceutical standards and polyacrylic resin III (Polyacrylic Resin III) that meets pharmaceutical standards in a mass ratio of 0.8:2.5; mix the outer layer membrane material with 95% polyethylene glycol in a ratio of 1:5 to prepare an outer layer membrane solution; send the single-layer coated particles and the outer layer membrane solution into the coating equipment to prepare a feed additive with a methionine selenium content of about 33g / 100g, and the embedding conditions are the same as those in the preparation of the single-layer coated particles.

[0056] 2. Preparation of feed: The feed additive prepared in the above step 1 is fully mixed with concentrated feed and roughage in a mass ratio of 0.05:20:55 to obtain feed for the experimental group, and the concentrated feed and roughage are fully mixed in a mass ratio of 20:55 to obtain feed for the blank control group; in this embodiment, the concentrated feed is soybean meal and the roughage is silage corn.

[0057] 3. Acquisition of fresh milk: Dairy cows with a lactation period of 150 days were used to feed the blank control group and the experimental group feed for 20 consecutive days, and the fresh milk produced by the cows after 20 days of feeding was obtained for processing and testing.

[0058] 4. Use the following process for processing

[0059] ① After the fresh milk has gone through the processes of milk purification, impurity removal and fat separation, it is microfiltered and sterilized using a ceramic membrane at a temperature of 50°C and a membrane pore size of 1.4um.

[0060] ②Use RO membrane concentration technology to make the protein reach 3.8±0.02g / 100g.

[0061] ③ Steam injection sterilization was used at a temperature of 154°C / 0.25s and a preheating temperature of 78°C, and milk was obtained after aseptic filling.

[0062] 5. Testing experiment

[0063] The detection methods in Table 1 were used to detect the milk selenium and DHA in the processed milk corresponding to the blank control group and the experimental group.

[0064] The processed milk corresponding to the blank control group and the experimental group was subjected to a mouse experiment, and the mouse experiment was conducted according to the following method:

[0065] ① 60 rats over 10 months old (weight 20-22g / rat) were selected and divided into two groups, one experimental group and one blank control group, with 30 rats in each group.

[0066] ②The recommended intake of this product is 2 packs (250g*2) / day. Calculated based on an adult body weight of 60kg, the converted intake is: 8g / kg (BW). In the mouse experiment, 10ml / kg (BW) was used for oral gavage (approximately 1 times the adult dose). The control group was fed with the same amount of processed cow's milk from the blank control group, once a day.

[0067] ③ After continuous intragastric administration for 30 days, the mice were subjected to the following tests in Table 1: glutathione peroxidase (GSH-Px activity), total superoxide dismutase (T-SOD), malondialdehyde (MDA), antibody-producing cell detection, serum hemolysin determination, and delayed-type hypersensitivity index test:

[0068] Table 1

[0069]

[0070] In this embodiment, the test results are shown in Table 2 below.

[0071] Table 2

[0072]

[0073] In the fresh milk processing process of the present invention, there is no significant difference in milk selenium before and after sterilization; by comparing the blank control group and the experimental group, it can be seen that the selenium content in the cow's milk of the experimental group is significantly higher than that of the blank control group. Compared with the blank control group, when the amount of selenium added in the feed is only about 0.44 mg / kg, the milk selenium content is increased from 2.32 ug / 100g to 13.5 ug / 100g, and the effect is significant.

[0074] Embodiment 2:

[0075] 1. Preparation of feed additives:

[0076] ① Starch and methionine selenium are mixed evenly in a mass ratio of 0.5:1, and the above substances are dissolved in corn protein powder hydrolyzate. The weight of the corn protein powder hydrolyzate solution is 4 times that of organic selenium. The above mixture is used as the core material raw material, and 0.3% of the phospholipids based on the total weight of the carrier and organic selenium are added. The mixture is passed through a homogenizer at 50°C and 160bar. After mixing evenly, the mixture is dried at 70°C, crushed and granulated to obtain core material particles.

[0077] ② Weigh carnauba wax in a ratio of 1:6 and dissolve in 95% ethanol solution, stirring at 100 rpm / min to dissolve as the embedding layer solution;

[0078] ③ Weigh the core material particles and the embedding layer solution, mix them at a mass ratio of ethyl cellulose to core material of 0.5:10, and then send them into the coating equipment at a flow rate of 3.5L / min and an inlet air temperature of 85℃ for embedding to obtain single-layer coated particles.

[0079] ④ Weigh single-layer coated particles and outer layer membrane materials in a mass ratio of 1:0.6, wherein the outer layer membrane material is polyacrylic acid resin II, and prepare an outer layer membrane solution by mixing the outer layer membrane material with polyethylene glycol in a ratio of 1:3. The single-layer coated particles and the outer layer membrane solution are sent into a coating device to prepare a feed additive with a methionine selenium content of 40g / 100g. The encapsulation conditions in this step are the same as those in the preparation of single-layer coated particles.

[0080] 2. Preparation of feed: The feed additive prepared in the above step 1 is fully mixed with concentrated feed and roughage in a mass ratio of 0.03:25:60 to obtain feed for the experimental group, and the concentrated feed and roughage are fully mixed in a mass ratio of 25:60 to obtain feed for the blank control group; in this embodiment, the concentrated feed is soybean meal and the roughage is silage corn.

[0081] 3. Acquisition of fresh milk: Dairy cows in lactation period of 10 days were used to feed blank control group and experimental group feed for 25 consecutive days, and fresh milk produced by the cows after 25 days of feeding was obtained.

[0082] 4. Use the following process for processing

[0083] ① After the fresh milk has gone through the milk purification and impurity removal processes, it is microfiltered and sterilized using a ceramic membrane at a temperature of 50°C and a membrane pore size of 1.4um.

[0084] ②Use RO membrane concentration technology to make the protein reach 3.8±0.02g / 100g.

[0085] ③Use tubular sterilization at a temperature of 137°C / 4s, and obtain milk after aseptic filling.

[0086] The test was carried out in the same manner as in Example 1, and the test results are shown in Table 3 below.

[0087] Table 3

[0088]

[0089] In the fresh milk processing process of the present invention, there is no significant difference in milk selenium before and after sterilization; by comparing the blank control group and the experimental group, it can be seen that the selenium content in the cow's milk of the experimental group is significantly higher than that of the blank control group. Compared with the blank control group, when the amount of selenium added in the feed is only about 0.28 mg / kg, the milk selenium content is increased from 2.4 ug / 100g to 12.1 ug / 100g, and the effect is significant.

[0090] Embodiment 3:

[0091] 1. Preparation of feed additives:

[0092] ① Mix hydroxypropyl methylcellulose and methionine selenium in a mass ratio of 0.8:1, dissolve the above substances in water to prepare a 55% solution (that is, the sum of the masses of hydroxypropyl methylcellulose and methionine selenium is 55% of the total mass), which is used as the core material raw material. After mixing evenly, dry at 80°C, crush and granulate to obtain core material particles.

[0093] ② Weigh polyacrylic acid resin II in a mass ratio of 0.5:10 to the core material, mix and dissolve in 95% ethanol solution in a ratio of 1:5, and stir and dissolve at 200 rpm / min to obtain the embedding layer solution.

[0094] ③ Weigh the core material particles and the embedding layer solution in a ratio of 10:2, mix them and send them into the coating equipment at a flow rate of 1L / min and an inlet air temperature of 70°C for embedding to obtain a feed additive with a methionine selenium content of about 54g / 100g.

[0095] 2. Preparation of feed: The feed additive prepared in the above step 1 is fully mixed with concentrated feed and roughage in a mass ratio of 0.03:25:60 to obtain feed for the experimental group, and the concentrated feed and roughage are fully mixed in a mass ratio of 25:60 to obtain feed for the blank control group; in this embodiment, the concentrated feed is soybean meal and the roughage is silage corn.

[0096] 3. Acquisition of fresh milk: Dairy cows with a lactation period of 150 days were used to feed the blank control group and the experimental group feed for 20 consecutive days, and fresh milk produced by the cows after 20 days of feeding was obtained.

[0097] 4. Use the following process for processing

[0098] ① After the fresh milk has gone through the milk purification and impurity removal processes, it is microfiltered and sterilized using a ceramic membrane at a temperature of 50°C and a membrane pore size of 1.4um.

[0099] ②Use RO membrane concentration technology to make the protein reach 3.8±0.02g / 100g.

[0100] ③ Steam injection sterilization was used at a temperature of 154°C / 0.25s and a preheating temperature of 76°C, and milk was obtained after aseptic filling.

[0101] The test was carried out in the same manner as in Example 1, and the test results are shown in Table 4 below.

[0102] Table 4

[0103]

[0104] In the fresh milk processing process of the present invention, there is no significant difference in milk selenium before and after sterilization; by comparing the blank control group and the experimental group, it can be seen that the selenium content in the cow's milk of the experimental group is significantly higher than that of the blank control group. Compared with the blank control group, when the amount of selenium added in the feed is only about 0.4 mg / kg, the selenium content is increased from 2.2 ug / 100g to 10.5 ug / 100g, and the effect is significant.

[0105] Embodiment 4:

[0106] The difference between this embodiment and embodiment 1 is that homolanine selenium is used instead of methionine selenium, and a feed additive containing an equal amount of selenium is added when preparing the feed.

[0107] The test was carried out in the same manner as in Example 1, and the test results are shown in Table 5 below.

[0108] Table 5

[0109]

[0110] In the fresh milk processing process of the present invention, there is no significant difference in milk selenium before and after sterilization; by comparing the blank control group and the experimental group, it can be seen that the selenium content in the cow's milk of the experimental group is significantly higher than that of the blank control group. Compared with the blank control group, the selenium content is increased from 2.12ug / 100g to 9.1ug / 100g.

[0111] At the same time, by comparing this embodiment with Example 1, it can be seen that although the same selenium content and dosage of homolanolin selenium (homollanolin selenium is also an organic selenium) are used, the milk selenium content also decreases significantly, indicating that the conversion of milk selenium depends on the stability of the embedded organic selenium, proving that when the organic selenium in the present invention is methionine selenium, the selenium conversion rate is higher.

[0112] Embodiment 5:

[0113] The only difference between this embodiment and embodiment 1 is that the ratio of β-cyclodextrin, methionine selenium and fucoidan in embodiment 1 is adjusted to 0.7:1.2:0.05, and the rest is the same as embodiment 1; that is, 0.3% of the total weight of phospholipids of the carrier and organic selenium are added to the core material, and the weight of the corn protein powder hydrolyzate solution is 3 times that of the organic selenium; the mass ratio of ethyl cellulose content to core material is 0.3:10; the mass ratio of single-layer coating particles to outer layer membrane material is 1:0.7.

[0114] The test was carried out in the same manner as in Example 1, and the test results are shown in Table 6 below.

[0115] Table 6

[0116]

[0117]

[0118] In the fresh milk processing process of the present invention, there is no significant difference in milk selenium before and after sterilization; by comparing the blank control group and the experimental group, it can be seen that the selenium content in the cow's milk of the experimental group is significantly higher than that of the blank control group. Compared with the blank control group, the selenium content is increased from 2.09ug / 100g to 9.7ug / 100g.

[0119] At the same time, by comparing this embodiment with Example 1, it can be seen that if the ratio of the core material filler to the organic selenium is inappropriate, even if the embedding ratio of the organic selenium is increased, the content of the final conversion to emulsified selenium will also decrease, indicating that the conversion of organic selenium in the feed depends on the ratio of organic selenium to other fillers. It is proved that when the weight ratio of organic selenium to the carrier is within 1: (0.5-0.8), the selenium conversion rate is better, and preferably 1:0.7 when the selenium conversion rate is higher.

[0120] Embodiment 6:

[0121] The only difference between this embodiment and embodiment 1 is that the mass ratio of the core material particles to the embedding layer solution is adjusted to 10:1, and the rest is the same as embodiment 1; that is, the preparation process of the core material particles is exactly the same as that in embodiment 1; the mass ratio of the ethyl cellulose content to the core material is 0.1:10; the mass ratio of the single-layer coating particles to the outer layer membrane material is 1:0.7.

[0122] The test was carried out in the same manner as in Example 1, and the test results are shown in Table 7 below.

[0123] Table 7

[0124]

[0125] In the fresh milk processing process of the present invention, there is no significant difference in milk selenium before and after sterilization; by comparing the blank control group and the experimental group, it can be seen that the selenium content in the milk of the experimental group is significantly higher than that of the blank control group. Compared with the blank control group, the selenium content is increased from 2.51ug / 100g to 11.4ug / 100g.

[0126] At the same time, by comparing this embodiment with Example 1, it can be seen that by increasing the proportion of core material in the single-layer coated particles, although the content of organic selenium also increases accordingly, the conversion rate is lower than that of Example 1, indicating that the ratio of core material to embedding layer has an impact on the effective release of organic selenium passing through the rumen and in the small intestine. It is proved that when the mass ratio of coating to core material in the present invention is in the range of (0.30-0.60):10, the conversion rate of selenium is higher.

[0127] Example 7

[0128] The difference between this embodiment and embodiment 1 is that the concentrated feed used is corn flour, and the roughage used is alfalfa, and the rest is the same as embodiment 1.

[0129] The test was carried out in the same manner as in Example 1, and the test results are shown in Table 8 below.

[0130] Table 8

[0131]

[0132] In the fresh milk processing process of the present invention, there is no significant difference in milk selenium before and after sterilization; by comparing the blank control group and the experimental group, it can be seen that the selenium content in the cow's milk of the experimental group is significantly higher than that of the blank control group. Compared with the blank control group, the selenium content is increased from 2.36ug / 100g to 13.32ug / 100g.

[0133] At the same time, by comparing this embodiment with embodiment 1, it can be seen that the selection of roughage and concentrated feed has no significant effect on the various indicators of the experimental group.

[0134] Comparative Example 1:

[0135] The difference between this comparative example and Example 1 is that the same amount of methionine selenium as in Example 1 is directly added to the feed, that is, 33% of the weight of the feed additive in Example 1 is added. Specifically, methionine selenium is fully mixed with concentrated feed and roughage according to the mass ratio of (0.05*33%):20:55 to obtain the feed for the experimental group, and the other subsequent steps are the same as in Example 1.

[0136] The test was carried out in the same manner as in Example 1, and the test results are shown in Table 9 below.

[0137] Table 9

[0138]

[0139] In the fresh milk processing process of the present invention, there is no significant difference in milk selenium before and after sterilization; by comparing the blank control group and the experimental group, it can be seen that the selenium content in the cow's milk of the experimental group is higher than that of the blank control group. Compared with the blank control group, the selenium content is increased from 2.42ug / 100g to 5.91ug / 100g, which is smaller than that of Example 1. It can be seen that the effect of unencapsulated selenium is significantly inferior to that of embedded selenium.

[0140] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A feed additive, characterized in that: Including core material and coating; The core material includes a carrier and organic selenium, and the envelope at least includes a material that is stable in the rumen environment and has a swelling effect in the small intestine; The selenium content in the feed additive is 0.6-1.5 g / kg.

2. A feed additive according to claim 1, characterized in that: The carrier is at least one of starch, β-cyclodextrin, hydroxypropyl methylcellulose, chitosan, sodium alginate, and silicon dioxide; And / or, the coating is at least one of glyceryl monostearate, glyceryl monolaurate, carnauba wax, palm oil, polyacrylic acid resin and ethyl cellulose. When the coating is at least one of glyceryl monostearate, glyceryl monolaurate, carnauba wax, palm oil and ethyl cellulose, an outer film is further provided on the coating, and the outer film is polyacrylic acid resin; And / or, the organic selenium is at least one of methionine selenium and homolanine selenium.

3. A feed additive according to claim 2, characterized in that: The mass ratio of the sum of the mass of the envelope and the core material to the mass of the outer film is 1:(0.6-0.8); And / or, the outer layer film is polyacrylic acid resin II and / or polyacrylic acid resin III; preferably, when the outer layer film is polyacrylic acid resin II and polyacrylic acid resin III, the mass ratio of polyacrylic acid resin II to polyacrylic acid resin III is (0.6-1): (2-3.3).

4. A feed additive according to any one of claims 1 to 3, characterized in that: The weight ratio of the organic selenium to the carrier is 1:0.5-0.8, preferably 1:0.7; And / or, the mass ratio of the coating to the core material is (0.15-0.60):10, preferably (0.3-0.6):

10.

5. A feed additive according to any one of claims 1 to 4, characterized in that: The core material further comprises at least one of fucoidan, corn protein powder hydrolyzate and an emulsifier; Preferably, the corn gluten powder hydrolysate is a supernatant obtained by centrifuging a corn gluten powder aqueous solution after protease hydrolysis and enzyme inactivation; and / or, the emulsifier is phospholipid; Preferably, the mass ratio of the organic selenium to fucoidan is 1:(0.02-0.08); and / or, the added amount of the corn protein powder hydrolyzate solution is 2-4 times that of the organic selenium; and / or, the mass of the emulsifier is 0.3% of the total weight of the carrier and the organic selenium.

6. A feed additive according to claim 5, characterized in that: The preparation process of the corn protein meal hydrolyzate is as follows: Weigh corn gluten powder, add water and mix well, adjust the substrate concentration to 6-10g / 100mL, adjust the pH to 10-12 with sodium hydroxide, stir well for 10-15min at 60°C, and then stand for hydration to obtain a hydrolysis substrate; adjust the pH to the reaction pH of protease with an acid-base regulator, add 2200-4000U / g of protease, perform enzymolysis at 50-60°C, and after enzymolysis for 2-4h, heat to 85°C to inactivate the enzyme for 10-15min; centrifuge to obtain a supernatant, which is the corn gluten powder hydrolyzate, the centrifugation parameter is 4500-5000r / min, the centrifugation is 15-25min, and the soluble solid concentration in the supernatant is 30mg / kg; The protease includes at least one of alkaline protease, neutral protease, trypsin and papain.

7. A process for preparing a feed additive, characterized in that: include: Preparation of core material: the carrier and organic selenium are mixed in a solvent, and after homogenization, they are dried, crushed, and granulated to obtain core material particles. Preferably, the homogenization conditions are 40-50°C, 160-180 bar, and the drying temperature is 70-90°C; or, after mixing the organic selenium with the solvent, they are sprayed onto the carrier that is boiling and expanding under high temperature conditions, and the core material particles are prepared after drying and low-temperature curing. Preferably, the temperature of the high temperature condition is 220-240°C, the drying temperature is 110-120°C, and the low-temperature curing temperature is -10--15°C; Preparation of the coating: Mix the coating with an organic solvent to prepare an embedding layer solution. Preferably, the mass ratio of the coating to the organic solvent is 1:(5-10). Then, the core material particles are coated with the embedding layer solution. Preferably, the mass ratio of the core material particles to the embedding layer solution is 10:(2-4).

8. The preparation process according to claim 7, characterized in that: The parameters when the embedding layer solution is used to coat the core material particles are: embedding layer solution flow rate 0.05-3.5 L / min, air inlet temperature 45-85°C, air outlet temperature 20-30°C, time 3-4h; And / or, in the preparation of the core material, the solvent is water and / or corn protein powder hydrolyzate.

9. A feed, characterized in that: The feed additive comprises the feed additive according to any one of claims 1 to 6.

10. A feed according to claim 9, characterized in that: The feed additive is added in an amount of 0.02 to 0.10%; Preferably, the feed comprises feed additives, concentrated feed and roughage in a mass ratio of (0.03-0.06):(15-25):(45-60); More preferably, the concentrate feed comprises at least one of rumen bypass choline, rumen bypass glucose, rumen bypass lysine, yeast powder, vitamins, minerals, corn flour, and soybean meal; preferably, the vitamins comprise at least one of vitamin D3, vitamin K3, vitamin B1, vitamin B2, vitamin B6, folic acid, pantothenic acid, and niacin; and / or, the mineral elements comprise at least one of copper, iron, manganese, zinc, and iodine; More preferably, the roughage includes at least one of silage corn, oat hay, alfalfa hay and forage grass.

11. A method for obtaining selenium-enriched milk, characterized in that: The feed is obtained by continuously feeding the feed according to claim 9 or 10 to dairy cows with a lactation period of 10 to 210 days for 15 to 45 days.

12. A method for processing selenium-enriched milk, characterized in that: The method comprises the steps of milk obtained by the method of claim 11, which is obtained after milk purification, impurity removal, microfiltration and sterilization, concentration and sterilization; The selenium content in the milk after the processing step reaches above 9ug / 100g.

13. A selenium-enriched milk, characterized in that: The product is prepared by the obtaining method of claim 11 or the processing method of claim 12.

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