Heat stress resistant plant essential oil feed additive as well as preparation method and application thereof

Abstract

The invention relates to the technical field of feed additives, in particular to a plant essential oil feed additive as well as a preparation method and application thereof. The plant essential oil feed additive comprises 0.1-0.5 part of green prickleyash essential oil, 0.2-0.5 part of cinnamon essential oil, 0.1-0.5 part of chili oil, 5-10 parts of a honeysuckle flower extract, 1-5 parts of a yucca extract, 5-10 parts of chicory powder, 1-5 parts of menthol, 55-70 parts of a carrier, 1-5 parts of lactic acid, 1-5 parts of cobalt chloride, 1-5 parts of saccharin sodium salt and 1-5 parts of guar gum. The carrier is attapulgite and calcium silicate, and the mass ratio of the attapulgite to the calcium silicate is (5-7): 1. The plant essential oil feed additive can obviously improve the heat stress reaction of animals, is especially suitable for heat stress resistance of ruminants such as sheep and beef cattle, improves the dry matter feed intake and the coarse feed feed intake by helping the ruminants to resist heat stress, further improves the daily gain, and is obvious in application effect and wide in market prospect.

Description

Technical Field

[0001] The invention relates to the technical field of feed additives, and in particular to a heat stress resistant plant essential oil feed additive and a preparation method and application thereof. Background Art

[0002] Intensive and large-scale farming has made stress an important factor affecting animal production performance and the economic benefits of the farming industry. According to statistics, the global economic losses caused by stress amount to hundreds of millions of yuan. Heat stress refers to a stress response that occurs when the ambient temperature rises above the optimum temperature zone, causing an imbalance in the animal's heat storage and heat dissipation mechanisms. The increase in ambient temperature and humidity makes it more difficult for ruminants to dissipate heat to the environment and achieve internal balance. The process of ruminants adapting to high ambient temperatures will lead to reduced feed intake, increased respiratory rate, reduced activity and increased water consumption to promote the dissipation of excess heat. In addition, heat stress can also have a series of adverse effects on metabolic processes, endocrine status and immune responses. In severe cases, it can also lead to the death of ruminants, causing huge economic losses to the farming industry. The way the farming industry copes with heat stress is mainly through physical cooling and antibiotics. The cost of physical cooling in high temperature and high humidity in summer is very high, and the long-term use of antibiotics may produce toxic side effects and drug residues. And due to public health risks and environmental issues, regulatory restrictions on the use of antibiotics have been imposed around the world. Therefore, the research, development and innovation of green, efficient and eco-friendly breeding technologies are of great significance to maintaining my country's food and public health security, promoting the transformation and upgrading of animal husbandry and improving the overall competitiveness of livestock products.

[0003] Plant essential oils have small molecules, strong permeability, can penetrate cell walls and cell membranes, damage cell membranes and plasma membranes of organelles, cause extravasation of cell contents and changes in ion gradients, affect the gene expression regulation process of pathogenic microorganisms, and ultimately cause the death of microorganisms. Due to its wide range of anti-inflammatory, antibacterial, antiviral and antioxidant biological activities, plant essential oils have great application potential in the field of aquaculture. They are a potential source of new antibacterial compounds and have become a frontier in the world's research on antibiotic-free aquaculture. However, the high volatility of plant essential oils means that they cannot act continuously on pathogenic microorganisms, which limits their application in livestock and poultry production.

[0004] At present, oregano essential oil has excellent effects in resisting heat stress, improving immunity and anti-oxidation of livestock and poultry, and has been widely recognized by the breeding industry at home and abroad. However, due to the small planting area of ​​oregano in China, the price of imported oregano is about ten times that of domestic oregano. At the same time, there is a large gap between my country and developed countries such as the United States in the basic research field of plant essential oil application, especially the late start of research on plant essential oil immobilization, micronization, preparation technology and its practical application in the field of breeding. The stability of plant essential oil is poor, and the advantages of rich aromatic plant resources have not been transformed into product advantages, which limits its application in efficient and healthy livestock breeding. Therefore, it is of great economic value to screen domestically distributed, simple purification process, high essential oil yield, stable and consistent performance, and relatively low cost characteristic aromatic plant resources, develop plant essential oil fixation and micronization technology, determine a cost-effective plant essential oil preparation process technology system, and combine with non-nutritional additives to create functional plant essential oil health maintenance products.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a plant essential oil feed additive and a preparation method and application thereof.

[0007] Specifically, the technical solution of the present invention is as follows: In the first aspect, the present invention provides a plant essential oil feed additive, which includes the following components in mass fractions: 0.1-0.5 parts of green pepper essential oil, 0.2-0.5 parts of cinnamon essential oil, 0.1-0.5 parts of chili oil, 5-10 parts of honeysuckle extract, 1-5 parts of yucca extract, 5-10 parts of chicory powder, 1-5 parts of menthol, 55-70 parts of a carrier, 1-5 parts of lactic acid, 1-5 parts of cobalt chloride, 1-5 parts of saccharin sodium and 1-5 parts of guar gum; the carrier is attapulgite and calcium silicate, and the mass ratio of attapulgite to calcium silicate is 5-7:1, preferably 6:1.

[0008] Preferably, the plant essential oil feed additive comprises the following components in parts by mass: 0.1-0.3 parts of green pepper essential oil, 0.2-0.3 parts of cinnamon essential oil, 0.1-0.3 parts of chili oil, 5-6 parts of honeysuckle extract, 4-5 parts of yucca extract, 5-7 parts of chicory powder, 1-3 parts of menthol, 65-70 parts of carrier, 1-2 parts of lactic acid, 1-2 parts of cobalt chloride, 3-5 parts of saccharin sodium and 1-2 parts of guar gum.

[0009] More preferably, the plant essential oil feed additive comprises the following components in parts by mass: 0.3 parts of green pepper essential oil, 0.2 parts of cinnamon essential oil, 0.1 parts of chili oil, 5 parts of honeysuckle extract, 5 parts of yucca extract, 5 parts of chicory powder, 1 part of menthol, 70 parts of carrier, 1 part of lactic acid, 1 part of cobalt chloride, 5 parts of saccharin sodium and 1 part of guar gum.

[0010] In a second aspect, the present invention provides a method for preparing the plant essential oil feed additive, comprising the following steps: placing green pepper essential oil, cinnamon essential oil and chili oil in an emulsified dispersion system, subjecting them to emulsified ultrasonic treatment, and then fixing them on a carrier wall material, and finally mixing them with the remaining components.

[0011] Preferably, the emulsified dispersion system comprises Tween 80, Span 60 and anhydrous ethanol, and the volume ratio of Tween 80, Span 60 and anhydrous ethanol is 1-2:1-2:1-2, more preferably 1:1:1.

[0012] Preferably, the emulsification ultrasonic treatment includes an emulsification step and an ultrasonic step, the rotation speed of the emulsification step is 2000-3000rpm, more preferably 2500rpm; the frequency of the ultrasonic treatment is 15-25kHz, more preferably 20kHz; the time is 5-15min, more preferably 10min.

[0013] Preferably, the fixing method is: stirring at room temperature (20-30°C) for 25-35 minutes.

[0014] In a third aspect, the present invention provides an animal feed, which comprises a basic feed and also comprises the plant essential oil feed additive or the plant essential oil feed additive prepared by the preparation method.

[0015] In a fourth aspect, the present invention provides use of the plant essential oil feed additive or the plant essential oil feed additive prepared by the preparation method or the animal feed in improving animal resistance to heat stress.

[0016] Preferably, the animal is a ruminant.

[0017] More preferably, the animal is sheep and / or beef cattle, wherein the beef cattle preferably include Simmental cattle.

[0018] Beneficial effects: The present invention provides a plant essential oil feed additive and a preparation method and application thereof. The plant essential oil feed additive provided by the present invention comprises the following components by mass: 0.1-0.5 parts of green pepper essential oil, 0.2-0.5 parts of cinnamon essential oil, 0.1-0.5 parts of chili oil, 5-10 parts of honeysuckle extract, 1-5 parts of yucca extract, 5-10 parts of chicory powder, 1-5 parts of menthol, 55-70 parts of carrier, 1-5 parts of lactic acid, 1-5 parts of cobalt chloride, 1-5 parts of saccharin sodium and 1-5 parts of guar gum; the carrier is attapulgite and calcium silicate, and the mass ratio of attapulgite to calcium silicate is 5-7:1. The plant essential oil feed additive provided by the present invention can significantly improve the heat stress reaction of animals, and is particularly suitable for the heat stress resistance of ruminants such as sheep and beef cattle. It helps ruminants resist heat stress to increase dry matter intake and roughage intake, thereby increasing daily weight gain, and has obvious application effects and broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be described below.

[0020] Figure 1 The particle size comparison under a microscope of the essential oil droplets after emulsification treatment in Example 5 of the present invention and the essential oil droplets without emulsification treatment is shown.

[0021] Figure 2 The temperature and humidity index changes in the animal experiments in Examples 6 and 7 of the present invention are shown. DETAILED DESCRIPTION

[0022] The object of the present invention is to provide a plant essential oil feed additive for resisting heat stress of ruminants, and its active ingredients are composed of a variety of plant essential oils and Chinese herbal medicine extracts. The nutrients contained in plant essential oils and Chinese herbal medicine extracts are diverse, and the biologically active ingredients are rich, and they have the dual nature of nutrition and medicine. The present invention deeply excavates the biological activities of different plant essential oils and the synergistic and antagonistic effects between them and Chinese herbal medicine extracts, and accurately formulates the plant essential oil feed additive formula, which is of great significance for improving the conversion efficiency of nutrients, so that it can not only help ruminants resist heat stress, but also effectively prevent the invasion of harmful pathogens. At the same time, the plant essential oil feed additive of the present invention also has the characteristics of being natural, less toxic and side effects, not easy to produce drug resistance and drug residues, and can meet the needs of intensive and large-scale breeding industry.

[0023] Specifically, the above object of the present invention is achieved through the following technical solutions: First, the present invention provides a feed additive for ruminants for relieving heat stress, which is made of the following raw materials in parts by mass: 0.1-0.5 parts of green pepper essential oil, 0.2-0.5 parts of cinnamon essential oil, 0.1-0.5 parts of chili oil, 5-10 parts of honeysuckle extract, 1-5 parts of yucca extract, 5-10 parts of chicory powder, 1-5 parts of menthol, 55-70 parts of a carrier, 1-5 parts of lactic acid, 1-5 parts of cobalt chloride, 1-5 parts of saccharin sodium and 1-5 parts of guar gum; the carrier is attapulgite and calcium silicate, and the mass ratio of attapulgite to calcium silicate is 5-7:1, preferably 6:1.

[0024] Further, the present invention provides a preparation method of the feed additive, which specifically comprises the following steps: firstly, the emulsifiers Tween 80 and Span 60 are mixed in a volume ratio of 1:1, and then an equal volume of anhydrous ethanol of a co-surfactant is added to mix (the volume ratio of Tween 80, Span 60 and anhydrous ethanol is 1:1:1), and then placed in a water bath pot with a magnetic stirrer and heated in a water bath at 20°C to fully melt the emulsifier and mix evenly. Then, the mixed essential oil (green pepper oleoresin, cinnamon essential oil, chili oil) is stirred and poured into the mixed emulsifier (the ratio of the mixed essential oil to the emulsifier is 1:6), and then deionized water is added dropwise, and the mixture is stirred in a vortex for 5 minutes, and an Ultra-Turrax homogenizer is used for pre-emulsification for 3 minutes at a speed of 2500 rpm, and then a VCX 750 ultrasonic processor is used to ultrasonically treat the sample at a frequency of 20 kHz for 10 minutes to prepare an essential oil emulsion with a mass fraction of 5%±1%. The emulsion is then loaded into a carrier. Through the essential oil emulsion and the carrier, the essential oil is fixed and micronized, and the essential oil is converted into droplets. The diameter of the released essential oil droplets is less than 5 microns, the surface area is increased by 20 times, and it is highly stable in the acidic environment of the gastrointestinal tract. It can be better preserved and improve the disadvantage of essential oil volatility. At the same time, it is more conducive to fully mixing with feed and making full use of plant essential oils. Its resistance to heat stress, antioxidant, and immunity is improved, and the intake of roughage and nutrient absorption are increased, the palatability of feed is improved, and better response to disease challenges is achieved to achieve health maintenance.

[0025] In one of the more specific embodiments (Example 5), the present invention provides a method for preparing a mixed plant essential oil feed additive that can relieve heat stress in ruminants. During the preparation, the liquid essential oil is loaded in a carrier, and the essential oil is converted into droplets, so that the diameter of the released essential oil droplets is less than 5 microns, the surface area is increased by 20 times, and it has a high degree of stability in the acidic environment of the gastrointestinal tract, such as Figure 1 This preparation method realizes the micronization of essential oils, which can continuously act on pathogenic microorganisms, reduce various stresses, improve immune function and nutrient absorption, improve palatability, better cope with disease challenges and thus achieve health maintenance.

[0026] Under moderate and severe heat stress conditions (Example 6 and Example 7), when the present invention is used, the plant essential oil feed additive is evenly added to the concentrate at an amount of 0.3-0.5%, and after feeding, the antioxidant property is improved, the immune performance is promoted, the dry matter intake and the roughage intake are promoted, the rectal temperature, the body surface temperature and the respiratory rate are reduced, the daily weight gain is increased, and the feed conversion rate percentage can be increased. Moreover, this product does not contain any antibiotics and chemicals, does not pollute the environment, and has no harmful substance residues.

[0027] Compared with the prior art, the present invention has the following significant advantages: by using emulsifiers Tween and Span to convert essential oil into droplets, the diameter of the released essential oil droplets is less than 5 microns, the surface area is increased by 20 times, and it has high stability in the acidic environment of the gastrointestinal tract, and through the carrier, the essential oil is fixed and micronized, and can continuously act on pathogenic microorganisms, reduce various stresses, improve immune function and nutrient absorption, improve palatability, better respond to disease challenges and achieve health maintenance. In addition, the product of the present invention is green and pollution-free, eliminates safety hazards such as drug resistance and drug residues, and has broad market prospects.

[0028] The technical solutions provided by the present invention are described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present invention. Unless otherwise specified, the test methods used in the examples are conventional methods; the materials and reagents used can be obtained from commercial sources.

[0029] In the following embodiments: Green pepper essential oil was purchased from Guizhou Xuande Biotechnology Co., Ltd.; cinnamon essential oil was purchased from Guizhou Xuande Biotechnology Co., Ltd.; chili oil was purchased from Guizhou Xuande Biotechnology Co., Ltd.; honeysuckle extract was purchased from Lanzhou Yunyuan Biotechnology Development Co., Ltd.; yucca extract was purchased from Xi'an Ruierli Bioengineering Co., Ltd.; chicory powder was purchased from Xi'an Ruierli Bioengineering Co., Ltd.; menthol was purchased from Jiangxi Xinsen Natural Vegetable Oil Co., Ltd.; attapulgite was purchased from Zhaochen Mineral Products Co., Ltd., Lingshou County, Shijiazhuang City, Hebei Province (specification: 60-80 mesh); calcium silicate was purchased from Lanzhou Yunyuan Biotechnology Development Co., Ltd.; lactic acid was purchased from Henan Xiaoxun Biotechnology Co., Ltd.; cobalt chloride was purchased from Bainachuan Chemical Business Department, Licheng District, Jinan City; saccharin sodium was purchased from Hebei Jiuxing Chemical Products Co., Ltd.; guar gum: Hebei Jiuxing Chemical Products Co., Ltd.

[0030] Example 1

[0031] This embodiment provides a mixed plant essential oil feed additive that can alleviate heat stress in ruminants, and its formula is as follows: According to the weight ratio, take 0.3 parts of green pepper essential oil; 0.2 parts of cinnamon essential oil; 0.1 parts of chili oil; 5 parts of honeysuckle extract; 5 parts of yucca extract; 5 parts of chicory powder; 1 part of menthol; 70 parts of carrier; 1 part of lactic acid, 1 part of cobalt chloride, 5 parts of saccharin sodium, and 1 part of guar gum.

[0032] Example 2

[0033] This embodiment provides a mixed plant essential oil feed additive that can alleviate heat stress in ruminants, and its formula is as follows: According to the weight ratio, take 0.1 parts of green pepper essential oil; 0.2 parts of cinnamon essential oil; 0.3 parts of chili oil; 6 parts of honeysuckle extract; 4 parts of yucca extract; 7 parts of chicory powder; 3 parts of menthol; 65 parts of carrier; 2 parts of lactic acid, 2 parts of cobalt chloride, 3 parts of saccharin sodium, and 2 parts of guar gum.

[0034] Example 3

[0035] This embodiment provides a mixed plant essential oil feed additive that can alleviate heat stress in ruminants, and its formula is as follows: According to the weight ratio, take 0.2 parts of green pepper essential oil; 0.3 parts of cinnamon essential oil; 0.1 parts of chili oil; 10 parts of honeysuckle extract; 3 parts of yucca extract; 5 parts of chicory powder; 3 parts of menthol; 60 parts of carrier; 4 parts of lactic acid, 3 parts of cobalt chloride, 5 parts of saccharin sodium, and 1 part of guar gum.

[0036] Example 4

[0037] This embodiment provides a mixed plant essential oil feed additive that can alleviate heat stress in ruminants, and its formula is as follows: According to the weight ratio, take 0.5 parts of green pepper essential oil, 0.5 parts of cinnamon essential oil, 0.5 parts of chili oil, 7 parts of honeysuckle extract, 1 part of yucca extract, 10 parts of chicory powder, 5 parts of menthol, 55 parts of carrier, 5 parts of lactic acid, 5 parts of cobalt chloride, 1 part of saccharin sodium, and 5 parts of guar gum.

[0038] Example 5

[0039] This embodiment provides a method for preparing the plant essential oil feed additive described in embodiments 1-4, comprising the following steps: (1) Micronization of essential oils: Tween 80, Span 80 and anhydrous ethanol were mixed at a ratio of 1:1:1 (volume ratio) at room temperature to form a mixed surfactant. Mixed essential oils (green pepper essential oil, cinnamon essential oil, chili oil) were weighed and mixed with the mixed surfactant at a ratio of 1:6 (volume ratio), and then deionized water was added dropwise, vortexed for 5 minutes, and pre-emulsified for 3 minutes using an Ultra-Turrax homogenizer at a speed of 2500 rpm, and then the sample was ultrasonicated for 10 minutes using a VCX 750 ultrasonic processor at a frequency of 20 kHz to prepare an emulsified solution of essential oil with a mass fraction of 5%.

[0040] (2) Fixation of essential oils: The emulsified solution of the mixed plant essential oils and the carrier are mixed at a mass ratio of 12:70 and stirred for 30 minutes, so that the emulsified solution of the mixed essential oils is fixed in the essential oil carrier (carrier) to maintain higher thermal stability.

[0041] (3) Mixing: After fixation and micronization, pour the remaining components (honeysuckle extract, yucca extract, chicory powder, menthol, lactic acid, cobalt chloride, saccharin sodium and guar gum) into the blender and stir at a fixed speed of 60r / min for two hours to fully mix all the components of the additive. This is a plant essential oil feed additive that can relieve heat stress in ruminants and improve their meat quality.

[0042] The preparation method provided in this embodiment loads the liquid essential oil into a carrier, converts the essential oil into droplets, makes the diameter of the released essential oil droplets less than 5 microns, increases the surface area by 20 times, and has high stability in the acidic environment of the gastrointestinal tract, can be better preserved, improves the disadvantage of the essential oil being volatile, and is more conducive to fully mixing with the feed, making full use of the plant essential oil. For the comparison of the particle size of the essential oil droplets after emulsification in this embodiment and the essential oil droplets without emulsification treatment, see Figure 1 .

[0043] Example 6

[0044] In this example, sheep were used as test animals to verify the effect of the plant essential oil feed additive, and the application effect was obvious.

[0045] Specifically, firstly, a 10-day preliminary test was conducted on sheep by feeding the feed additives provided in Examples 1-4 of the present invention, and the optimal feed additive formula was screened based on daily weight gain. The test method is as follows: Forty crossbred (Mongolian × Slender-tailed Han) female lambs (about 3 months old, initial body weight 18.3 ± 0.23 kg) were selected as subjects and randomly divided into 5 groups (8 lambs in each group). The experimental treatments included (1) the CON group, which was fed with a basal diet supplemented with 4 g of carrier (attapulgite and calcium silicate mixed at a mass ratio of 6:1) per kg of concentrate; (2) the ESE1 group, which was fed with a basal diet supplemented with 4 g of ESE1 (the feed additive provided in Example 1) per kg of concentrate; (3) the ESE2 group, which was fed with a basal diet supplemented with 4 g of ESE2 (the feed additive provided in Example 2) per kg of concentrate; (4) the ESE3 group, which was fed with a basal diet supplemented with 4 g of ESE3 (the feed additive provided in Example 3) per kg of concentrate; (5) the ESE4 group, which was fed with a basal diet supplemented with 4 g of ESE4 (the feed additive provided in Example 4) per kg of concentrate; the basal diets were formulated according to the nutritional requirements of sheep of NRC (2012). The CON group and the ESE (1-4) groups were housed in the same environment, had the same feeding time (06:00 and 18:00), and were fed twice a day. Roughage (corn straw, alfalfa straw, wheat straw, etc.) and concentrated feed (corn, soybean meal, compound plant essential oil, etc.) were fed separately. The feeding interval was half an hour, and the roughage was fed first and then the concentrated feed. The test results are shown in Table 1.

[0046] Table 1

[0047] The test results showed that there was no significant difference in the initial body weight of the sheep in the control group and the test groups ( P >0.05), and there was no significant difference in the final weight of sheep between the control group and each experimental group ( P >0.05), but the final weight of the sheep in the ESE1 group was higher than that in the control group and other experimental groups, and the daily weight gain in the ESE1 group was also significantly higher than that in the control group and other experimental groups ( P <0.001). Therefore, the feed additive used in the ESE1 group had the best effect on alleviating heat stress in sheep and improving feed intake and growth performance.

[0048] The feed additive provided in Example 1 of the present invention was used to feed sheep, and the test method was as follows: Thirty-two female crossbred (Mongolian × fine-tailed Han sheep) lambs (approximately 3 months old, with an initial body weight of 18.3 ± 0.23 kg) were selected as subjects. Lambs were randomly divided into 2 groups (16 lambs in each group), with 4 replicates in each group (4 lambs in each replicate). The experimental treatments included (1) the CON group, which was fed a basal diet supplemented with 4 g of carrier (attapulgite and calcium silicate mixed in a mass ratio of 6:1) per kg of concentrate; and (2) the ESE group, which was fed a basal diet supplemented with 4 g of ESE per kg of concentrate; the basal diet was formulated according to the nutritional requirements of sheep in the NRC (2012). The CON and ESE groups were housed in the same environment and fed at the same time (06:00 and 18:00) twice a day for a total of 45 days. Roughage (corn straw, alfalfa straw, wheat straw, etc.) and concentrate (corn, soybean meal, compound plant essential oil, etc.) were fed separately. The feeding interval is half an hour, and roughage is fed first, followed by concentrated feed.

[0049] The test results are shown in Table 2-10.

[0050] The test results show that after adding 4g of the product of the present invention to each kg of concentrate, the heat stress index during the entire test period is generally higher than that of ordinary heat stress (see Figure 2 ), the average daily dry matter intake of the experimental group was 33.21 g higher than that of the control group, and the average daily roughage intake of the experimental group was 101.66 g higher than that of the control group, with extremely significant differences ( P <0.001), the feed conversion rate of the experimental group was also significantly higher than that of the control group ( P <0.001)(see Table 2); the average final weight of lambs in the experimental group was 1.6 kg higher than that in the control group, and the difference was significant ( P =0.06); and the average daily weight gain of the experimental group was 56.8 g higher than that of the control group, and the difference was significant ( P <0.05)(see Table 3); the measured sheep physiological parameters including respiratory rate, rectal temperature and body surface temperature in the experimental group were significantly lower than those in the control group ( P <0.05), which shows that adding ESE to sheep diet under heat stress conditions can alleviate the adverse effects of heat stress on sheep's physiological indicators (see Table 4). Among the blood immune indicators measured, except IL-6, the numerical experiments of other immune indicators

[0051] The test group was higher than the control group (see Table 5), and the difference in IgM was significant ( P=0.06), indicating that the immune level of the experimental group has been greatly improved; in the measured blood antioxidant index, the T-SOD value of the experimental group was higher than that of the control group, indicating that the T-SOD level of the experimental group has been greatly improved (see Table 6); in the measured blood heat stress index, the HSP-70 value of the experimental group was higher than that of the control group, indicating that the HSP-70 level of the experimental group has been improved (see Table 7); during the experiment, the serum biochemical indexes, blood leukocyte indexes, and blood image indexes of sheep were also measured, but after comparing the control group with the experimental group, it was found that there were no significant differences in these indexes ( P >0.05) (see Tables 8, 9, and 10).

[0052] Table 2 Concentrated feed, roughage and water intake

[0053] Table 3 Weight changes

[0054] Table 4 Physiological response indexes of sheep

[0055] Table 5 Blood immune indexes

[0056] Table 6 Blood antioxidant indexes

[0057] Table 7 Blood heat stress index

[0058] Table 8 Serum biochemical indexes

[0059] Table 9 Blood white blood cell index

[0060] Table 10 Blood picture index

[0061] Example 7

[0062] In this example, Simmental crossbred bulls were used as test animals to verify the effect of the plant essential oil feed additive, and the application effect was obvious.

[0063] Specifically, the feed additive provided in Example 1 of the present invention (the feed additive in Example 1 with the best effect in the sheep preliminary test) is used to feed beef cattle, and the test method is as follows: Twenty Simmental crossbred bulls in good health and weighing 442 (± 72.49) kg were randomly divided into two groups. The experimental treatments included (1) the CON group, which was fed a basal diet supplemented with 4 g of carrier (attapulgite and calcium silicate mixed in a mass ratio of 6:1) per kg of concentrate; and (2) the ESE group, which was fed a basal diet supplemented with 4 g of ESE per kg of concentrate. The pre-feeding period was 14 days, and the experimental period was 30 days, for a total of 44 days. According to the weight and fattening goals of the experimental cattle, the target daily weight gain, the minimum cost and the best effect of the nutritional standards of beef cattle in NRC (2016) were used to design the complete feed in stages. Before the start of the experiment, the cattle shed was disinfected, the health of the experimental cattle was checked, the internal deworming, vaccination and numbering were performed. The experiment adopted a total mixed ration (TMR) feeding mode, feeding once at 06:00 and 18:00 each day, free feeding, and careful observation of the feeding of the experimental cattle every day, and data records were kept.

[0064] The test results are shown in Tables 11-13.

[0065] The test results show that after adding 4g of the product of the present invention to each kg of concentrate, the heat stress index during the entire test period is generally higher than that of ordinary heat stress (see Figure 2 ), as shown in Table 11, the difference in body weight between the control group and the experimental group was very small at d0, but at the end of the experiment at d42, the average body weight of the experimental group was 23 kg higher than that of the control group, and during the experiment, the average daily weight gain of the experimental group was 0.51 kg higher than that of the control group, and the difference was extremely significant ( P <0.05). In the physiological and biochemical indicators of beef cattle blood, as shown in Table 12, the reduced glutathione of the control group at d0 was 78.5 higher than that of the experimental group, and the difference was extremely significant; while at d42, the reduced glutathione of the control group and the experimental group were basically equal. In the routine indicators of beef cattle blood, as shown in Table 13, there was no significant difference in the number of basophils between the control group and the experimental group at d0, but at d42, the number of basophils in the experimental group was significantly higher than that in the control group, and the difference was extremely significant ( P <0.05); at d0, the mean corpuscular hemoglobin concentration of the control group was higher than that of the experimental group, while at d42, the mean corpuscular hemoglobin concentration of the control group was lower than that of the experimental group, and the difference was significant ( P =0.055).

[0066] Table 11 Growth performance of beef cattle

[0067] Table 12 Blood physiological and biochemical indicators

[0068] Table 13 Routine blood indexes

[0069] In summary, the present invention screened the characteristic aromatic plant resources which are widely distributed in China, have stable and consistent properties and are relatively low in cost, and finally developed a heat-resistant plant essential oil feed additive with good effect. The feed additive utilizes carriers to fix and micronize plant essential oils, overcomes the deficiencies and defects of the prior art, has obvious heat-resistant effects on ruminants such as sheep and beef cattle, and can be combined with non-nutritional additives to create functional plant essential oil health maintenance products.

[0070] The above-described embodiments only express several implementation methods of the present invention, which are convenient for understanding the technical solution of the present invention in detail, but cannot be understood as limiting the scope of protection of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the scope of protection of the present invention.

Claims

1. A plant essential oil feed additive, characterized in that: The invention comprises the following components in parts by mass: 0.1-0.5 parts of green pepper essential oil, 0.2-0.5 parts of cinnamon essential oil, 0.1-0.5 parts of chili oil, 5-10 parts of honeysuckle extract, 1-5 parts of yucca extract, 5-10 parts of chicory powder, 1-5 parts of menthol, 55-70 parts of carrier, 1-5 parts of lactic acid, 1-5 parts of cobalt chloride, 1-5 parts of sodium saccharin and 1-5 parts of guar gum; the carrier is attapulgite and calcium silicate, and the mass ratio of attapulgite to calcium silicate is 5-7:

1.

2. The plant essential oil feed additive according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 0.1-0.3 parts of green pepper essential oil, 0.2-0.3 parts of cinnamon essential oil, 0.1-0.3 parts of chili oil, 5-6 parts of honeysuckle extract, 4-5 parts of yucca extract, 5-7 parts of chicory powder, 1-3 parts of menthol, 65-70 parts of carrier, 1-2 parts of lactic acid, 1-2 parts of cobalt chloride, 3-5 parts of saccharin sodium and 1-2 parts of guar gum.

3. The method for preparing the plant essential oil feed additive according to claim 1 or 2, characterized in that: The method comprises the following steps: placing green pepper essential oil, cinnamon essential oil and chili oil in an emulsified dispersion system, subjecting the system to emulsified ultrasonic treatment, fixing the system to a carrier wall material, and finally mixing the system with the remaining components.

4. The preparation method according to claim 3, characterized in that: The emulsified dispersion system comprises Tween 80, Span 60 and anhydrous ethanol; the volume ratio of Tween 80, Span 60 and anhydrous ethanol is 1-2:1-2:1-2.

5. The preparation method according to claim 3, characterized in that: The emulsification ultrasonic treatment comprises an emulsification step and an ultrasonic step, the rotation speed of the emulsification step is 2000-3000 rpm, the frequency of the ultrasonic treatment is 15-25 kHz, and the time is 5-15 min.

6. The preparation method according to claim 3, characterized in that: The fixing method is: stirring at room temperature for 25-35 minutes.

7. Animal feed, characterized in that The invention comprises a basic feed and also comprises the plant essential oil feed additive according to claim 1 or 2 or the plant essential oil feed additive prepared by the preparation method according to any one of claims 3 to 6.

8. Use of the plant essential oil feed additive according to claim 1 or 2, or the plant essential oil feed additive prepared by the preparation method according to any one of claims 3 to 6, or the animal feed according to claim 7 in improving the heat stress resistance of animals.

9. The use according to claim 8, characterized in that: The animal is a ruminant.

10. The use according to claim 8, characterized in that: The animals are sheep and / or beef cattle.

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