Plant extraction slow-release agent for reducing ammonia and methane emission of dairy cow and preparation method of plant extraction slow-release agent

Abstract

The invention provides a plant extraction slow-release agent for reducing ammonia and methane emission of dairy cows and a preparation method thereof, and relates to the technical field of veterinary plant extract preparations. The sustained-release agent is mainly prepared from lychee seed extract, mushroom extract, centella asiatica extract, rosa laevigata michx extract, eucalyptus leaf extract and myrobalan extract. Supplementary feeding of the plant-extracted slow-release agent in daily ration of dairy cows has an obvious improvement effect on production performance and milk quality of the dairy cows. Meanwhile, the apparent digestibility of the organism to nutrient substances such as crude protein, crude fat and neutral detergent fiber can be remarkably improved, the absorption of the organism to the nutrient substances in the feed is promoted, and the bioavailability is improved. What's more important is that when the plant extraction slow-release agent is supplemented and fed in daily ration of dairy cows, the total discharge amount of manure nitrogen, urine nitrogen and nitrogen can be remarkably reduced, meanwhile, the rumen fermentation index is improved, methane emission is reduced, environmental pollution is reduced, and green and efficient development of the breeding industry is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of veterinary plant extract preparations, and in particular to a plant extract sustained-release agent for reducing ammonia and methane emissions from dairy cows and a preparation method thereof. Background Art

[0002] In recent years, with the improvement of people's living standards, the demand for dairy products has gradually increased, driving the rapid development of the dairy farming industry. Dairy farming is a highly polluting industry, prone to causing serious environmental pollution problems. Therefore, the environmental protection requirements for dairy farming are becoming increasingly stringent, which is also one of the major challenges facing dairy farming. Among them, nitrogenous excrement and methane are the most significant sources of pollution emissions in dairy farming.

[0003] Cattle are the livestock that emit the most greenhouse gases, with the majority of these emissions occurring during farming as methane. Methane not only exacerbates global warming but also contributes to feed energy loss. One kilogram of methane produced is equivalent to approximately 17.7 kilograms of standard milk or 1.3 kilograms of beef, making it crucial to control methane emissions from dairy cows.

[0004] Nitrogen is an essential nutrient for animals, and its metabolism plays a crucial role in animal growth, development, and product quality. Compared to non-ruminant animals, dairy cows have a relatively low efficiency in utilizing dietary nitrogen. Reports indicate that the efficiency of converting dietary nitrogen into milk nitrogen or body weight gain is 27% and 14%, respectively. 70%-80% of this nitrogen (not retained in body tissues or secreted in milk) is excreted in urine and feces, with approximately 50% of this nitrogen excreted in urine and 25-30% excreted in feces. This leads to resource waste, water pollution (urinary nitrogen emissions), and air pollution (gaseous nitrogen emissions and the formation of small particulate matter in the atmosphere). With the rapid growth of the global population, the demand for nitrogen resources and a healthy environment continues to increase.

[0005] Nitrogen and methane excretion from dairy cattle production can negatively impact ecosystem sustainability and human health. Furthermore, the rising price of soybean meal is placing a burden on dairy production costs. Conserving nitrogen and carbon resources, improving nitrogen and carbon metabolism, and reducing nitrogen and carbon emissions to the environment are pressing challenges in dairy farming.

[0006] Due to the risk of antibiotic resistance and drug residues in livestock products, people have paid more attention to it. Most countries, including my country, have banned the use of antibiotics in feed. Plant extracts have several secondary metabolites that have antibacterial activity against bacteria, fungi and viruses when extracted and concentrated. At the same time, these secondary compounds have strong antibacterial activity and can affect certain physiological parameters of animals, so they are considered to be substitutes for antibiotics. Some bioactive phytochemicals can be used as potential natural substitutes for antibiotics, which are beneficial for regulating rumen fermentation and animal growth performance. Based on the above background, the present invention aims to provide a multi-plant extract composite sustained-release agent for reducing ammonia and methane emissions from dairy cows. Summary of the Invention

[0007] (1) Technical problems solved

[0008] In view of the deficiencies in the prior art, the present invention provides a plant-extracted slow-release agent for reducing ammonia and methane emissions from dairy cows and a preparation method thereof.

[0009] (2) Technical solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0011] Firstly, the present invention provides a plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows. The plant extract slow-release agent is made of 70-80% plant extract, 10-20% coating wall material and 5-10% slow-release auxiliary material.

[0012] Furthermore, the plant extract sustained-release agent is made of 70-75% of plant extract, 15-20% of coating wall material and 5-10% of sustained-release excipient.

[0013] Furthermore, the plant extract sustained-release agent is made of 70% plant extract, 20% coating wall material and 10% sustained-release excipient.

[0014] Furthermore, the plant extract is prepared from the following raw materials in parts by weight: 10-30 parts of litchi kernel extract, 5-20 parts of shiitake mushroom extract, 5-20 parts of Centella asiatica extract, 10-30 parts of Rosa laevigata extract, 1-10 parts of eucalyptus leaf extract, and 5-20 parts of Terminalia chebula extract.

[0015] Furthermore, the plant extract sustained-release agent is prepared from the following raw materials in parts by weight: 15-25 parts of litchi seed extract, 10-20 parts of shiitake mushroom extract, 5-15 parts of Centella asiatica extract, 15-25 parts of Rosa laevigata extract, 1-6 parts of eucalyptus leaf extract, and 5-15 parts of Terminalia chebula extract.

[0016] Furthermore, the plant extract sustained-release agent is made from the following raw materials in parts by weight: 20 parts of litchi kernel extract, 16 parts of shiitake mushroom extract, 10 parts of Centella asiatica extract, 20 parts of Rosa laevigata extract, 3 parts of eucalyptus leaf extract, and 10 parts of Terminalia chebula extract.

[0017] Furthermore, litchi seed extract, shiitake mushroom extract, Centella asiatica extract, Rosa laevigata extract, eucalyptus leaf extract, and Terminalia chebula extract are respectively prepared into powdered products using litchi seed, shiitake mushroom, Centella asiatica, Rosa laevigata, eucalyptus leaf, and Terminalia chebula as raw materials using conventional extraction methods. The conventional extraction methods include solvent extraction, supercritical carbon dioxide extraction, ultrasound-assisted extraction, and microwave-assisted extraction.

[0018] Furthermore, litchi seed extract, shiitake mushroom extract, Centella asiatica extract, Rosa laevigata fruit extract, eucalyptus leaf extract, and Terminalia chebula fruit extract can be purchased commercially.

[0019] Furthermore, the coating wall material is one of hydroxypropyl methylcellulose, polyacrylic acid resin III, and cellulose acetate phthalate; preferably, the coating wall material is cellulose acetate phthalate.

[0020] Furthermore, the sustained-release excipient is one of methylcellulose, alginate, and chitosan; preferably, the sustained-release excipient is methylcellulose.

[0021] In addition, the present invention also provides a plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows. The plant extract slow-release agent is prepared according to the following steps:

[0022] (1) Weigh 10-30 parts of litchi seed extract, 5-20 parts of shiitake mushroom extract, 5-20 parts of Centella asiatica extract, 10-30 parts of Rosa laevigata extract, 10-30 parts of eucalyptus leaf extract, and 5-20 parts of Terminalia chebula extract according to the following weight parts, mix them evenly to obtain the plant extract, and set aside;

[0023] (2) After uniformly mixing 70-80% of the plant extract and 5-10% of the sustained-release excipient, a starch slurry with a concentration of 10-15% was added, and the mixture was stirred for more than 30 minutes to obtain a pelleting material, which was then extruded and spheronized to obtain wet pellets with a particle size of 2-3 mm, and then dried at below 50°C to a moisture content of less than 3%;

[0024] (3) dissolving 10-20% of the coating wall material in a mixed solution of acetone and ethanol at a volume ratio of 1:1 to prepare a coating solution with a concentration of 15-20%;

[0025] (4) Using fluidized bed coating technology, the dried pellets are placed in a fluidized bed and hot air at a temperature of 40-50°C is introduced to fluidize the pellets. The coating liquid is sprayed into the fluidized bed at a flow rate of 2-3 mL / min. The coating process lasts for 25-30 minutes, and the coating weight gain is controlled to be 3-6%. After the coating is completed, hot air is continued to be dried for more than 15 minutes to completely solidify the coating film, thereby obtaining the plant extract sustained-release agent.

[0026] (3) Beneficial effects

[0027] The present invention first takes traditional Chinese veterinary medicine syndrome differentiation and treatment as its principle, starting from spleen and stomach deficiency, qi stagnation and food accumulation, endogenous dampness and heat, and weak essence and fine particles, and targeting the growth characteristics and lactation characteristics of dairy cows, following the principle of monarch, minister, assistant and envoy compatibility, obtains a plant extract composed of litchi seed, shiitake mushroom, Rosa laevigata fruit, Centella asiatica, eucalyptus leaves, and Terminalia chebula as raw materials. Litchi seed warms the middle and promotes qi circulation, dissipates stagnation and relieves pain, and its yang-warming property can enhance the transportation and transformation of the spleen and stomach. Its qi-promoting and stagnation-dispersing properties can dredge the milk meridians, eliminate stagnation and relieve stagnation, making it the monarch drug. Shiitake mushroom is sweet in taste and neutral in nature, and has the functions of strengthening the body's resistance and replenishing deficiency, invigorating the spleen and stimulating the appetite. Together with litchi seed, it can enhance the transportation and transformation functions of the spleen and stomach, stimulate the appetite and help digestion, and promote nutrient absorption; Rosa laevigata fruit has the effects of consolidating essence and reducing urine, astringing the intestines and stopping diarrhea, can consolidate kidney essence, and improve the body's metabolic efficiency. The two are jointly ministerial drugs. Centella asiatica and eucalyptus leaves clear dampness and heat, detoxify and fight bacteria, and together maintain intestinal and mammary health, reduce the incidence of diarrhea and mastitis, and improve milk quality. Terminalia chebula has astringent and antidiarrheal properties, and together with Lentinus edodes and Rosa laevigata, it improves the body's absorption and utilization of nutrients. Terminalia chebula is also neutral in nature and can harmonize various medicinal herbs, guiding the meridians and collaterals. Together, the three herbs serve as adjuvants. The plant extract provided by the present invention improves digestion and absorption, reduces nutrient loss, and maintains health through comprehensive conditioning by regulating qi and promoting digestion, strengthening the spleen and replenishing qi, clearing heat and removing dampness, and consolidating essence and astringing the intestines, thereby achieving the purpose of improving the growth performance of dairy cows and milk quality.

[0028] The present invention uses the above-mentioned plant extract as a raw material to prepare a sustained-release formulation suitable for the rumen of dairy cows, which can exert a long-lasting effect, avoid the waste of active ingredients, and promote the body's absorption of active ingredients. Supplementing the plant extract sustained-release agent of the present invention in the diet of dairy cows can significantly increase the milk production of dairy cows, increase the milk fat rate and milk protein rate in milk, reduce the somatic cell count content, have a significant improvement effect on the production performance and milk quality of dairy cows, and can achieve the regulation of breast health level and reduce the risk of mastitis. At the same time, the plant extract sustained-release agent of the present invention can significantly increase the apparent digestibility of nutrients such as crude protein, crude fat and neutral detergent fiber, promote the body's absorption of nutrients in feed, and improve bioavailability. Importantly, supplementing the plant extract sustained-release agent of the present invention in the diet of dairy cows can significantly reduce fecal nitrogen, urine nitrogen and total nitrogen emissions, while improving rumen fermentation indicators, reducing methane emissions, reducing environmental pollution, and being conducive to the green and efficient development of the breeding industry. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] Example 1

[0031] A plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows, wherein the plant extract slow-release agent is prepared according to the following steps:

[0032] (1) According to the following weight parts, 20 parts of litchi seed extract, 16 parts of shiitake mushroom extract, 10 parts of Centella asiatica extract, 20 parts of Rosa laevigata extract, 3 parts of eucalyptus leaf extract, and 10 parts of Terminalia chebula extract were weighed and mixed uniformly to obtain a plant extract for later use;

[0033] (2) After 75% of the plant extract and 5% of the sustained-release excipient are mixed evenly, a starch slurry with a concentration of 15% is added, and the mixture is stirred for more than 30 minutes to obtain a pelleting material. Subsequently, wet granules of micropellets with a particle size of 2-3 mm are prepared by an extrusion-spheronization method, and then dried at below 50°C to a moisture content of less than 3%;

[0034] (3) dissolving 20% ​​of the coating wall material in a mixed solution of acetone and ethanol in a volume ratio of 1:1 to prepare a coating solution with a concentration of 20%;

[0035] (4) Using fluidized bed coating technology, the dried pellets were placed in a fluidized bed and hot air at 40°C was introduced to fluidize the pellets. The coating liquid was sprayed into the fluidized bed at a flow rate of 3 mL / min. The coating process lasted for 30 minutes, and the coating weight gain was controlled to be 4%. After the coating was completed, hot air was continued to be introduced for drying for more than 15 minutes to completely solidify the coating film, thereby obtaining the plant extract sustained-release agent.

[0036] The above-mentioned lychee seed extract, shiitake mushroom extract, Centella asiatica extract, Rosa laevigata fruit extract, eucalyptus leaf extract, and Terminalia chebula fruit extract were all purchased from commercial sources. Product specifications are shown in the following table:

[0037] name Product Specifications Main active ingredient content Lychee seed extract 10:1 Total saponins in litchi kernel ≥30% Shiitake mushroom extract 10:1 Lentinan ≥30% Centella asiatica extract 10:1 Centella asiatica total saponins ≥40% Rosa Laevigata Extract 10:1 Rosaponins ≥ 20% Eucalyptus leaf extract 10:1 Total flavonoids ≥ 10% Terminalia chebula extract 10:1 Tannin ≥10%

[0038] The coating wall material is one of hydroxypropyl methylcellulose, polyacrylic acid resin III, and cellulose acetate phthalate; preferably, the coating wall material is cellulose acetate phthalate.

[0039] Furthermore, the sustained-release excipient is one of methylcellulose, alginate, and chitosan; preferably, the sustained-release excipient is methylcellulose.

[0040] Example 2

[0041] The difference between this embodiment and embodiment 1 is that the plant extract sustained-release agent is made of 70% plant extract, 20% coating wall material and 10% sustained-release excipient.

[0042] Example 3

[0043] The difference between this embodiment and embodiment 1 is that the plant extract sustained-release agent is made of 80% plant extract, 15% coating wall material and 5% sustained-release excipient.

[0044] Example 4

[0045] The difference between this embodiment and embodiment 1 is that the plant extract is made from the following raw materials in parts by weight: 10 parts of litchi kernel extract, 5 parts of shiitake mushroom extract, 5 parts of Centella asiatica extract, 10 parts of Rosa laevigata extract, 1 part of eucalyptus leaf extract, and 5 parts of Terminalia chebula extract.

[0046] Example 5

[0047] The difference between this embodiment and embodiment 1 is that the plant extract is made from the following raw materials in parts by weight: 16 parts of litchi kernel extract, 12 parts of shiitake mushroom extract, 12 parts of Centella asiatica extract, 16 parts of Rosa laevigata extract, 3 parts of eucalyptus leaf extract, and 12 parts of Terminalia chebula extract.

[0048] Example 6

[0049] The difference between this embodiment and embodiment 1 is that the plant extract is made from the following raw materials in parts by weight: 30 parts of litchi kernel extract, 20 parts of shiitake mushroom extract, 20 parts of Centella asiatica extract, 30 parts of Rosa laevigata extract, 8 parts of eucalyptus leaf extract, and 20 parts of Terminalia chebula extract.

[0050] Example 7

[0051] Furthermore, the plant extract sustained-release agent is made from the following raw materials in parts by weight: 15 parts of litchi seed extract, 10 parts of shiitake mushroom extract, 5 parts of Centella asiatica extract, 15 parts of Rosa laevigata extract, 1 part of eucalyptus leaf extract, and 5 parts of Terminalia chebula extract.

[0052] Example 8

[0053] Furthermore, the plant extract sustained-release agent is made from the following raw materials in parts by weight: 25 parts of litchi seed extract, 20 parts of shiitake mushroom extract, 15 parts of Centella asiatica extract, 25 parts of Rosa laevigata extract, 6 parts of eucalyptus leaf extract, and 15 parts of Terminalia chebula extract.

[0054] Example 9

[0055] Furthermore, the plant extract sustained-release agent is made from the following raw materials in parts by weight: 22 parts of litchi seed extract, 18 parts of shiitake mushroom extract, 14 parts of Centella asiatica extract, 20 parts of Rosa laevigata extract, 4 parts of eucalyptus leaf extract, and 12 parts of Terminalia chebula extract.

[0056] Test example

[0057] 1 Materials and Methods

[0058] 1.1 Test materials

[0059] The plant extract sustained-release agent prepared in Example 1.

[0060] 1.2 Experimental design

[0061] Sixty healthy Holstein cows with similar milk production, lactation days, and parity were selected (Table 1) and divided into three groups of 20 cows each using a completely randomized experimental design. The control group was fed a basal diet, while the low-dose and high-dose groups were supplemented with the basal diet at 5g / d / cow and 10g / d / cow, respectively.

[0062] The test period is 60 days, with a pre-test period of 10 days and a formal period of 50 days.

[0063] To ensure the same external factors, all experimental cows were raised in the same cowshed. The cows were fed and milked three times a day on a regular basis. The daily residual feed rate was guaranteed to be 5-10%. They had free access to food and water, and the cowshed was disinfected daily.

[0064] The information of the experimental cattle and the composition of the basal diet and the nutritional level of the diet (dry matter basis) are shown in Tables 1 and 2, respectively.

[0065] Table 1 Information of experimental cattle

[0066] project control group Low-dose group High-dose group Breastfeeding days / d 74.29±10.69 77.36±13.09 72.39±12.67 Parity 2.40±0.68 2.45±0.60 2.45±0.69 Milk production / (kg / d) 44.09±5.78 43.81±6.03 44.51±4.36

[0067] Table 2 Composition of basal diet and nutritional level of diet (dry matter basis)

[0068] Diet composition content% Nutritional levels content Silage corn 20.00 Crude protein% 14.27 Peanut vines 40.00 Neutral detergent fiber% 34.37 corn 26.00 Acid detergent fiber% 22.72 bran 2.88 Crude fat% 3.40 soybean meal 2.00 calcium% 0.95 Distillers grains protein feed 4.00 phosphorus% 0.48 cottonseed 3.20 Crude ash% 9.89 Premix 1.60 Gross energy (MJ kg-1) 16.73 Xiao Su Da 0.32 total 100

[0069] Note: ① Premix provides the following per kilogram of diet: 100 mg iron, 500 mg copper, 350 mg zinc, 20,000 IU vitamin A, 6,000 IU vitamin D, 15,000 IU vitamin E; ② Nutritional levels are measured values.

[0070] 1.3 Production index performance measurement

[0071] Feed intake and residual feed were counted daily to calculate average daily dry matter intake (DMI). Milk production data for each group was recorded and average daily milk production was calculated. On the 60th day of the formal period, milk was milked at 6:00 AM, 12:00 PM, and 6:00 PM. Milk was collected and mixed in equal proportions. Milk fat percentage, milk protein percentage, lactose percentage, and milk cell count were measured for each group using a milk composition and milk cell analyzer.

[0072] 1.4 Apparent digestibility

[0073] Refer to the "Feed Analyzer Feed Quality Testing Technology" to test the apparent substance digestibility.

[0074] 1.5 Determination of nitrogen emission indicators

[0075] (1) At the end of the main test period, feces were collected for 24 hours for 3 consecutive days. The feces collected every day were mixed, weighed, and samples were kept. 25 mL of 10% sulfuric acid was added to every 100 g of feces sample for nitrogen fixation and then placed in a refrigerator for freezing at -20°C. On the last day of the sampling period, the feces samples collected every day were mixed with the nitrogen-fixed feces samples for 3 days according to the proportion of feces samples collected every day, and then placed in an oven to dry at 65°C to make air-dried samples.

[0076] (2) At the end of the trial period, urine was collected from dairy cows using the spot urine collection method, which combined artificial urine collection with bladder urine collection. The urine was collected twice a day with an interval of 12 hours for 3 consecutive days. The urine pH was adjusted to 2-3 using concentrated H2SO4 and stored at -20℃.

[0077] Refer to "Feed Analysis and Feed Quality Testing Technology" to determine the crude protein (CP) content in feces and use the Kjeldahl method to determine the urine nitrogen content. The calculation formula is as follows:

[0078] Fecal nitrogen (g / d) = daily fecal output × CP content in feces × 0.16

[0079] Urine nitrogen (g / d) = daily urine output × urine nitrogen content

[0080] Total nitrogen emissions (g / d) = fecal nitrogen + urine nitrogen

[0081] 1.6 Rumen fermentation performance determination

[0082] On the day the experiment ended, 50 mL of rumen fluid was collected from the dairy cows every day using a rumen catheter, filtered through four layers of gauze, and the supernatant was analyzed for rumen fermentation indicators according to the method of Wang Shuiping et al. (2007).

[0083] 1.7 Data Processing

[0084] The data were analyzed using Excel 2010, and one-way analysis of variance was performed using Prism 8.0.2. Duncan's method was used for multiple comparisons. The results were expressed as "mean ± standard deviation". P < 0.01 indicated an extremely significant difference, and P < 0.05 indicated a significant difference.

[0085] 2 Results

[0086] 2.1 Effect of the plant extract sustained-release agent of the present invention on the production performance of dairy cows

[0087] As shown in Table 3, the average daily dry matter intake of the low-dose and high-dose groups was higher than that of the control group, but there was no significant difference (P>0.05); the average daily milk production of the low-dose group was higher than that of the control group, but there was no significant difference (P>0.05); the average daily milk production of the high-dose group was significantly higher than that of the control group, and the difference was significant (P<0.05).

[0088] As shown in Table 4, the milk fat rate and milk protein rate of the low-dose and high-dose groups were significantly higher than those of the control group (P<0.05), and the somatic cell count was significantly lower than that of the control group (P<0.05). There was no significant difference in lactose rate among the groups (P>0.05).

[0089] Table 3 Average daily dry matter intake and average daily milk production of each group of experimental cows

[0090] Group Average daily dry matter intake (kg / d) Average daily milk production (kg / d) control group 23.03±1.75 44.69±0.74 Low-dose group 24.13±2.03 45.36±1.02 High-dose group 23.88±1.59 45.87±1.13*

[0091] Note: *P<0.05 compared with the control group.

[0092] Table 4 Milk composition of each group of experimental cows

[0093] Group Milk fat content (%) Milk protein rate (%) Lactose rate (%) <![CDATA[Somatic cell count (×10 4 / mL)]]> control group 3.68±0.18 3.26±0.07 4.56±0.08 15.36±0.28 Low-dose group 3.84±0.21* 3.46±0.10* 4.57±0.06 14.14±0.44* High-dose group 3.97±0.09* 3.55±0.06* 4.60±0.06 13.26±0.25*

[0094] Note: *P<0.05 compared with the control group.

[0095] 2.2 Effect of the plant extract sustained-release agent of the present invention on the apparent digestibility of nutrients in dairy cows

[0096] As shown in Table 5, the crude protein, crude fat, and neutral detergent fiber contents of the low-dose and high-dose groups were significantly increased compared with the control group (P<0.05). There were no significant differences in dry matter, organic matter, and acid detergent fiber contents among the groups (P>0.05).

[0097] Table 5 Apparent digestibility of nutrients in each group of experimental cattle (%)

[0098] project control group Low-dose group High-dose group dry matter 63.19±0.48 64.22±0.69 64.98±0.71 organic matter 70.22±0.84 72.16±0.76 73.23±0.85 crude protein 63.06±0.59 65.34±0.39* 66.72±0.58* crude fat 70.18±2.61 77.16±3.06* 83.64±2.43* Neutral detergent fiber 46.18±1.13 54.26±0.87* 56.39±0.76* Acid detergent fiber 37.66±0.63 38.39±0.74 39.09±0.39

[0099] Note: *P<0.05 compared with the control group.

[0100] 2.3 Effect of the plant extract sustained-release agent of the present invention on nitrogen emission of dairy cows

[0101] As shown in Table 6, compared with the control group, the total nitrogen excretion of fecal nitrogen and urine nitrogen in the low-dose group and the high-dose group were significantly reduced, and the difference was extremely significant (P<0.01).

[0102] Table 6 Nitrogen emissions of each group of experimental cattle (g / d)

[0103] Group fecal nitrogen Urine nitrogen Total nitrogen emissions control group 147.44±6.44 240.44±9.12 387.88±11.67 Low-dose group 129.20±5.34** 220.34±5.25** 349.54±7.39** High-dose group 117.48±5.79** 211.79±7.21** 239.27±10.28**

[0104] Note: Compared with the control group, *P<0.05, **P<0.01.

[0105] 2.4 Effect of the plant extract sustained-release agent of the present invention on rumen fermentation performance of dairy cows

[0106] As shown in Table 7, compared with the control group, the concentrations of ammonia nitrogen, volatile fatty acids, and butyrate in the low-dose group were slightly lower, with no significant differences (P>0.05). Acetic acid in the low-dose group was significantly lower, while propionic acid was significantly higher (P<0.05), and the acetic acid / propionic acid ratio was also significantly lower (P<0.05). Methane emissions in the low-dose group decreased by 19.14% compared with the control group, with a significant difference (P<0.05). Compared with the control group, the concentrations of ammonia nitrogen, volatile fatty acids, and propionic acid in the high-dose group were significantly lower (P<0.05), while the propionic acid concentration was significantly increased (P<0.05), and the acetic acid / propionic acid ratio was significantly lower than the control group (P<0.05). Methane emissions in the high-dose group decreased by 22.84% compared with the control group, with a significant difference (P<0.05).

[0107] Table 7 Rumen fermentation indexes of each group of experimental cattle

[0108] project control group Low-dose group High-dose group pH 6.58±0.03 6.59±0.01 6.58±0.02 Ammonia nitrogen (mg / dL) 20.19±1.03 19.49±0.14 17.47±1.28* Volatile fatty acids / mmol 57.37±0.33 56.22±0.56 53.05±0.74* Acetic acid (%) 37.45±0.54 35.68±0.30* 34.62±0.47* Propionic acid (%) 9.46±0.03 9.69±0.09* 10.01±0.24* Butyric acid (%) 7.03±0.14 7.23±0.14 7.66±0.04 Acetic acid / Propionic acid 3.96±0.06 3.68±0.03* 3.46±0.04* Methane (g / 100g VFA) 12.49±0.41 10.10±0.40* 9.64±0.12*

[0109] Note: *P<0.05 compared with the control group.

[0110] 3 Conclusion

[0111] Supplementing the plant extract slow-release agent of the present invention in the diet of dairy cows can significantly increase the milk production of dairy cows, increase the milk fat rate and milk protein rate in milk, reduce the somatic cell count content, have a significant improvement effect on the production performance and milk quality of dairy cows, can achieve the regulation of breast health level, and reduce the risk of mastitis. At the same time, the plant extract slow-release agent of the present invention can significantly increase the apparent digestibility of nutrients such as crude protein, crude fat and neutral detergent fiber, promote the body's absorption of nutrients in feed, and improve bioavailability. Importantly, supplementing the plant extract slow-release agent of the present invention in the diet of dairy cows can significantly reduce fecal nitrogen, urine nitrogen and total nitrogen emissions, while improving rumen fermentation indicators, reducing methane emissions, reducing environmental pollution, and being conducive to the green and efficient development of the aquaculture industry.

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows, characterized in that: The plant extract sustained-release agent is prepared from 70-80% of plant extract, 10-20% of coating wall material and 5-10% of sustained-release auxiliary material.

2. A plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows according to claim 1, characterized in that: The plant extract is prepared from the following raw materials in parts by weight: 10-30 parts of litchi seed extract, 5-20 parts of shiitake mushroom extract, 5-20 parts of Centella asiatica extract, 10-30 parts of Rosa laevigata extract, 1-10 parts of eucalyptus leaf extract, and 5-20 parts of Terminalia chebula extract.

3. The plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows according to claim 1, characterized in that: The plant extract sustained-release agent is prepared from the following raw materials in parts by weight: 15-25 parts of litchi seed extract, 10-20 parts of shiitake mushroom extract, 5-15 parts of Centella asiatica extract, 15-25 parts of Rosa laevigata extract, 1-6 parts of eucalyptus leaf extract, and 5-15 parts of Terminalia chebula extract.

4. The plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows according to claim 1, characterized in that: The plant extract sustained-release agent is prepared from the following raw materials in parts by weight: 20 parts of litchi seed extract, 16 parts of shiitake mushroom extract, 10 parts of Centella asiatica extract, 20 parts of Rosa laevigata extract, 3 parts of eucalyptus leaf extract, and 10 parts of Terminalia chebula extract.

5. The plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows according to claim 1, characterized in that: The coating wall material is one of hydroxypropyl methylcellulose, polyacrylic acid resin III, and cellulose acetate phthalate; preferably, the coating wall material is cellulose acetate phthalate.

6. The plant extract slow-release agent for reducing ammonia and methane emissions from dairy cows according to claim 1, characterized in that: The sustained-release excipient is one of methylcellulose, alginate, and chitosan; preferably, the sustained-release excipient is methylcellulose.

7. The preparation method of a plant extract sustained-release agent for reducing ammonia and methane emissions from dairy cows according to any one of claims 1 to 6, characterized in that: The plant extract sustained-release agent is prepared according to the following steps: (1) Weighing litchi seed extract, shiitake mushroom extract, Centella asiatica extract, Rosa laevigata extract, eucalyptus leaf extract, and Terminalia chebula extract according to the above weight parts, mixing them evenly to obtain a plant extract, and setting aside; (2) After uniformly mixing 70-80% of the plant extract and 5-10% of the sustained-release excipient, a starch slurry with a concentration of 10-15% was added, and the mixture was stirred for more than 30 minutes to obtain a pelleting material, which was then extruded and spheronized to obtain wet pellets with a particle size of 2-3 mm, and then dried at below 50°C to a moisture content of less than 3%; (3) dissolving 10-20% of the coating wall material in a mixed solution of acetone and ethanol at a volume ratio of 1:1 to prepare a coating solution with a concentration of 15-20%; (4) Using fluidized bed coating technology, the dried pellets are placed in a fluidized bed and hot air at a temperature of 40-50°C is introduced to fluidize the pellets. The coating liquid is sprayed into the fluidized bed at a flow rate of 2-3 mL / min. The coating process lasts for 25-30 minutes, and the coating weight gain is controlled to be 3-6%. After the coating is completed, hot air is continued to be dried for more than 15 minutes to completely solidify the coating film, thereby obtaining the plant extract sustained-release agent.