Method for feeding dairy sheep and fresh sheep milk

Abstract

A feeding method of dairy sheep relates to the technical field of feeding and the feeding method of dairy sheep. The feed for feeding includes roughage, concentrate and selenium preparation. Roughage and concentrate are added according to seasons during the growth period and recovery period of the dairy sheep, and roughage is reduced, concentrate is increased and the selenium preparation is added during the pregnancy period and lactation period. The concentrate includes corn, soybean meal, bran and trace elements, the trace elements include complex vitamins, salts and calcium preparation, the selenium preparation is fresh microalgae wet material rich in organic selenium, and the calcium preparation includes one or more of calcium hydrogen phosphate, bone meal and soybean meal. The compound feed composed of roughage, concentrate and fresh microalgae rich in selenium is used for feeding the dairy sheep, and fresh sheep milk rich in organic selenium and calcium is obtained.

Description

Technical Field

[0001] This invention relates to the field of animal husbandry technology, and in particular to a method for raising dairy goats and fresh goat milk rich in nutrients. Background Technology

[0002] Goat milk is nutritionally complete and easily digested and absorbed, and is considered the dairy product closest to human milk. The health and nutrition of the ewe directly affect the quantity and quality of the milk. Therefore, improving and ensuring adequate nutrition during pregnancy and lactation is a key factor in improving goat milk quality. Since selenium and calcium are essential trace elements for the human body, existing methods for producing selenium-enriched, high-calcium goat milk include directly adding inorganic selenium or calcium, such as calcium carbonate and sodium selenite, to the goat's feed during lactation. However, inorganic selenium is highly toxic and has a low absorption rate; long-term feeding can lead to its accumulation in the animal's body, affecting the goat's normal growth and development. Another method involves adding selenium fertilizer to crops to create selenium-enriched crops, such as spraying selenium onto corn to create selenium-containing corn, which is then fed to the goats. The converted organic selenium is easily utilized by the organisms. However, this method is time-consuming, cumbersome, and costly. Therefore, there is a need to develop a safe, low-cost, and simple method for raising goats and producing high-calcium, selenium-enriched fresh goat milk. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the existing technology and provide a method for feeding dairy goats, which uses a compound feed composed of roughage, concentrate and selenium-enriched fresh microalgae to feed dairy goats, and obtains fresh goat milk rich in organic selenium and calcium through this feeding method.

[0004] The technical problem described in this invention is solved by the following technical solution: A method for feeding dairy goats, wherein the feed for dairy goats includes roughage, concentrate, and selenium preparation. During the growth and recovery periods of dairy goats, roughage and concentrate are added according to the seasons for routine feeding. During pregnancy and lactation, roughage is reduced and concentrate is increased, and selenium preparation is added. The concentrate includes corn, soybean meal, wheat bran, and trace elements. The trace elements include compound vitamins, salts, and calcium preparations. The selenium preparation is fresh microalgae wet feed rich in organic selenium. The calcium preparation includes one or more of dicalcium phosphate, bone meal, and tofu residue.

[0005] The above-mentioned method for feeding dairy goats includes roughage consisting of one or more of the following: grain straw, alfalfa, peanut vines, or stems and leaves of leguminous plants, cut into small pieces; the proportions of each component of the concentrate feed during pregnancy and lactation are as follows by weight: corn 55-60 parts, soybean meal 30 parts, wheat bran 5 parts, and trace elements 5-10 parts, of which calcium preparations account for 3-5 parts; during pregnancy, feed 200-400g of fresh microalgae wet feed per goat daily, and during lactation, feed 400-600g per goat.

[0006] The above-mentioned method for feeding dairy goats involves microalgae composed of spirulina and chlorella. Spirulina and chlorella are cultured in a selenium-containing medium to obtain microalgae wet feed. Dairy goats in the lactation period are fed fresh microalgae wet feed every day, and milked 8 hours after feeding to obtain fresh goat milk containing organic selenium.

[0007] In the above-mentioned method for raising dairy goats, the microalgae are cultivated in a cultivation device located in the dairy goat farm. The cultivation device includes a cultivation box, a basic culture medium storage tank, a supplementary culture medium storage tank, a circulation tank, and a feed pipe. Each storage tank is connected to the cultivation box via the feed pipe. The cultivation box consists of an upper cuboid and a lower inverted triangle forming an interconnected space. A top plate is movably installed on the top of the cultivation box, and several ventilation holes are opened on the top plate. A liquid guide pipe is installed at the top of the cultivation box. A screen is installed at the bottom of the cultivation box, and the frame of the screen abuts against the wall of the cultivation box. An air inlet pipe and a heating rod are installed below the screen. A discharge port is installed at the bottom of the cultivation box.

[0008] In the above-mentioned method for raising dairy goats, the incubator is a multi-stage incubator connected in series, with connecting pipes between adjacent incubators. The discharge port of the upper-stage incubator is connected to one end of the connecting pipe, and the other end of the connecting pipe is connected to the liquid guide pipe of the lower-stage incubator. A discharge pipe is provided on the connecting pipe, and the discharge pipe is connected to a circulating storage tank.

[0009] The above-mentioned method for raising dairy goats, wherein the microalgae are cultured in an incubator, includes the following steps: a. Algal strain activation and scale-up culture: Spirulina and Chlorella strains were inoculated into activation medium for activation and scale-up culture for 3-5 days to obtain algal culture solutions of the two microalgae. b. Mixed culture: Inject the basic culture medium from the basic culture medium storage tank into the first-stage incubator. Inoculate the Spirulina and Chlorella strains obtained in step a into the first-stage incubator and culture them under light with aeration and stirring through the air inlet pipe. From the second day after inoculation until the day before harvest, add supplementary culture medium from the supplementary culture medium storage tank to the first-stage incubator daily, with the amount added being 1-5% of the incubator volume. After 7-10 days of culture, it can be harvested. Open the connecting pipe valve, and the culture medium in the first-stage incubator is discharged after being filtered through a screen. c. Feeding: The microalgae in the first-stage incubator are intercepted on the screen surface; open the top panel of the incubator and feed the dairy goats with wet microalgae feed around the incubator; d. Continuous cyclic culture: Add basic culture medium to the second-stage incubator, inoculate with Spirulina inoculum, and repeat step b for microalgae culture to achieve continuous and stable algae supply.

[0010] The above-mentioned method for feeding dairy goats includes a culture medium containing the following substances per liter: 3-5g NaHCO3, 0.3-1.0mg sodium selenite, 0.2g glucose, 0.1g urea, and a pH of 8.0-9.0; the water used to prepare the culture medium is deep well water or spring water.

[0011] In the above-mentioned method for raising dairy goats, in step b, the exhaust pipe is opened to allow gas to pass through the screen and form fine bubbles, causing microalgae to float and clump together on the surface of the culture medium; the exhaust volume is reduced and the valve of the bottom connecting pipe is opened, and the culture medium in the first-stage incubator is filtered through the screen and slowly flows out from the connecting pipe, part of which enters the next-stage incubator and part of which enters the circulating storage tank, while the microalgae are intercepted on the surface of the screen; the microalgae on the screen are fresh microalgae wet material.

[0012] In the above-mentioned method for raising dairy goats, in step d, the ratio of the basic culture medium in the second-stage incubator to the culture medium in the first-stage incubator is 7:3. From the third day after inoculation until the day before harvest, a mixture of supplementary culture medium and circulating culture medium is added daily, and the goats are harvested after 6-8 days of incubation.

[0013] A fresh goat milk, obtained by the above-mentioned method of raising dairy goats, wherein the fresh goat milk contains 0.10-0.30 mg / kg of organic selenium and 1200-1400 mg / kg of calcium.

[0014] This invention employs a feeding method that combines concentrated feed and roughage, supplemented with selenium and calcium preparations. The feed ratios are adjusted according to the seasons and the pregnancy, lactation, and recovery cycles of the dairy goats. During pregnancy and lactation, fresh microalgae wet feed and calcium-rich bone meal are added to supplement selenium. Spirulina and Chlorella are used to convert inorganic selenium into bioactive organic selenium. Feeding dairy goats with microalgae wet feed results in fresh goat milk containing animal protein selenium. This selenium supplementation method reduces feeding costs compared to adding organic selenium products such as selenomethionine and selenium-enriched yeast to feed, and avoids the stress response caused by the high selenium content of prepared selenium products, which is detrimental to the absorption and utilization of selenium by dairy goats. Simultaneously, fresh microalgae contains highly active organic selenium and various micronutrients, improving the conversion rate of effective components in dairy goats, enhancing their disease resistance, and thus improving milk quality. Fresh goat milk containing selenium protein is easily absorbed by the human body, further improving the utilization rate and safety of selenium supplementation. Drinking selenium-enriched goat milk every day can meet the body's selenium needs, achieving the purpose of strengthening the body and preventing diseases. Long-term consumption of selenium-enriched goat milk has a high bioconversion rate and is safe and effective.

[0015] Multi-stage incubators are used to produce selenium-enriched microalgae, enabling continuous cultivation in various locations. The production process is simple, featuring rapid microalgae growth and a short cultivation cycle. Furthermore, the continuous use of the culture medium effectively reduces costs. Fresh microalgae cells are high in active ingredients, rich in proteins, β-carotene, vitamins, and polysaccharides, among other bioactive substances. This allows dairy goats to supplement their diet with organic selenium and trace elements such as calcium and zinc while consuming fresh microalgae, increasing milk production by 10-20% and improving nutrient conversion rates. The bioavailability of organic selenium in microalgae by dairy goats reaches over 40%, far exceeding the 5%-15% of inorganic selenium.

[0016] The microalgal symbiotic system composed of Spirulina and Chlorella enriches and transforms inorganic selenium into easily absorbed organic selenium in a selenium-containing culture medium. The synergistic effect of the two microalgae, with simple nutritional requirements and autotrophic growth, allows the microalgae to multiply to the full capacity of the chamber in 6-10 days under natural light and artificial light conditions, with a selenium concentration of 1.5-4.5 mg / kg. This is a simple, safe and effective way to obtain organic selenium compounds. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the multi-stage incubator of the present invention; Figure 2 This is a cross-sectional view of the incubator of the present invention; Figure 3 yes Figure 2 AA view.

[0018] The list of labels in the diagram is as follows: 1. Frame, 2. First-stage incubator, 3. Second-stage incubator, 4. Feed pipe, 5. Air inlet pipe, 6. Connecting pipe, 7. Heating rod, 8. Screen, 9. Ventilation hole, 10. Liquid guide pipe, 11. Grille, 12. Top plate of the chamber, 13. Discharge pipe. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the embodiments.

[0020] This invention develops feeding methods and nutritional feeds for dairy goats during their growth, pregnancy, lactation, and recovery periods. During late pregnancy and lactation, a certain amount of nutrients containing selenium and calcium are added to the feed daily to ensure that the fresh goat milk contains organic selenium and calcium, which are easily absorbed by the human body, and to maintain a stable selenium and calcium content in the goat milk, thereby improving the quality and nutrition of the fresh goat milk.

[0021] The feed for dairy goats includes roughage, concentrate, and selenium preparations. The roughage includes one or more of the following: grain straw (including corn straw and wheat straw), alfalfa, peanut vines, or legume stems and leaves. Roughage should be cut into small pieces before feeding. The concentrate includes corn, soybean meal, wheat bran, and trace elements. Trace elements include a complex of vitamins, primarily vitamin C, inorganic salts, and calcium preparations. Calcium preparations include one or more of the following: dicalcium phosphate, bone meal, and tofu residue. The selenium preparation is a fresh, wet microalgae feed rich in organic selenium. The components of the concentrate, by weight, are: corn 55-70 parts, soybean meal 15-30 parts, wheat bran 5-10 parts, and trace elements 5 parts (including 1-3 parts calcium preparation).

[0022] During the growth and recovery periods of dairy goats, different feeds should be provided according to the four seasons, and the following steps should be followed: Step a: Regular feeding. The ratio of roughage to concentrate is 6:4 in summer and autumn, and 5:5 in winter and spring. The feeding schedule for each season is as follows: During the summer months of May to July, roughage can be fresh corn stalks or legume stems and leaves, and the concentrate feed ratio is 65 parts corn, 25 parts soybean meal, 5 parts wheat bran, and 5 parts trace elements. In autumn and early winter (August to December), roughage consists of fresh or silage corn stalks, alfalfa, and peanut vines, while the concentrate feed is formulated with 70 parts corn, 20 parts soybean meal, 5 parts wheat bran, and 5 parts trace elements. Increasing the proportion of corn in the feed is beneficial for fattening up for winter. Adding pine needle powder to the feed can improve immunity, resulting in bright coat and good condition for the sheep during winter.

[0023] During winter and spring (January to April), the roughage should be silage, and the concentrate feed ratio should be: 55-60 parts corn, 30 parts soybean meal, 5-10 parts wheat bran, and 5 parts trace elements. Increasing the protein content of soybean meal is beneficial for the recovery and growth of sheep in spring. Nuts such as sunflower seeds, rapeseed, and peanuts (after oil extraction) can also be added to replace some of the soybean meal to supplement protein and trace elements.

[0024] Step b: Feeding during pregnancy. During pregnancy, reduce the proportion of roughage and increase the proportion of concentrate, with a ratio of 4:6. Increase the amount of alfalfa in the roughage to over 50%, as alfalfa is a high-quality feed rich in various nutrients. From the fourth month of pregnancy to delivery and throughout the lactation period, appropriately increase the protein and calcium preparations containing bone meal in the concentrate. The concentrate ratio is 55-60 parts corn, 30 parts soybean meal, 5 parts wheat bran, and 5-10 parts trace elements (including 3-5 parts calcium preparation). Selenium preparation is also added to the feed. Feed pregnant and lactating dairy goats 200-400g of fresh microalgae wet feed daily. The selenium-enriched microalgae wet feed contains 1.5-4.5 mg / kg of selenium. When starting to feed microalgae, add 30% of the basal amount, then gradually increase by 5-10% daily, reaching the basal amount after 10 days. Use intermittent feeding, feeding for 6 days and stopping for 1 day, which saves costs and prevents selenium accumulation in tissues. Feeding selenium-enriched fresh microalgae can supplement selenium and some trace elements, enhance the immunity of dairy goats, and increase the organic selenium content in goat milk; at the same time, increasing the amount of bone meal is beneficial for calcium supplementation, and maintaining appropriate calcium levels helps the absorption of selenium and vitamin E.

[0025] Step c: Feeding during the lactation period. The roughage and concentrate feed for lactating goats after giving birth are the same as during pregnancy, with increased use of fresh microalgae wet feed. Feed each goat 400-600g of fresh microalgae wet feed daily. Milk 8-10 hours after feeding, once a day. After milking, use a breast pump to massage the udder. Each goat produces 1-3L of milk. The selenium content of the goat milk is stable at 0.10-0.30mg / kg (as Se), and the calcium content is 1200-1400mg / kg; its selenium content is much higher than the 0.03mg / kg of ordinary goat milk.

[0026] The fresh microalgae are cultivated in a culture device, and the culture solution is filtered upon harvest. The culture device is located in a dairy goat farm and includes a culture box, a basic culture solution storage tank, a supplementary culture solution storage tank, a circulation tank, and a feed pipe 4. The basic culture solution storage tank, the supplementary culture solution storage tank, and the circulation tank are all connected to the feed pipe 4, and the other end of the feed pipe 4 is connected to the culture box. Figures 1-3As shown, the incubator can be a two-stage or three-stage incubator. The figure shows a two-stage incubator. The incubator includes a frame 1, an air inlet pipe 5, a connecting pipe 6, a heating rod 7, and a first-stage incubator 2 and a second-stage incubator 3 that are interconnected. Both incubators are mounted on the frame 1, with the first-stage incubator 2 higher than the second-stage incubator 3. The incubator consists of an upper cuboid and a lower inverted triangle forming an interconnected space. The cuboid is 1.5-2m long and 0.6-0.8m wide, and the incubator is 0.3-0.5m high. A movable top plate 12 is installed on the top of the incubator, with several ventilation holes 9. A liquid guide pipe 10 is installed at the top of the incubator, extending along the length of the incubator, with several downward-facing holes on the pipe wall. The incubator and the top plate are made of transparent material, allowing light to penetrate into the incubator. A screen 8, made of woven synthetic fiber with a mesh size of 300, is installed in the inverted triangular area at the bottom of the incubator. The screen's frame abuts against the incubator wall and is made of iron plate. Below the screen 8, an air inlet pipe 5, a temperature sensor, and a heating rod 7 are located. The air inlet pipe and heating rod extend along the length of the incubator, and several small holes are evenly distributed on the wall of the air inlet pipe. A discharge port is located on the side wall at the bottom of the incubator, and grids 11 are installed on both sides of the incubator, with the distance between the grids slightly greater than the width of the sheep.

[0027] like Figure 1 As shown, the feed pipe 4 is connected to the liquid guide pipe 10 of the first-stage incubator 2, and is also connected to the liquid guide pipe 10 of the second-stage incubator 3 via a connecting pipe 6. The discharge port of the first-stage incubator 2 is equipped with a connecting pipe 6, the other end of which is connected to the liquid guide pipe 10 of the second-stage incubator. The culture medium from the first-stage incubator can be discharged to the second-stage incubator via the connecting pipe 6. A valve and a discharge pipe 13 are installed on the connecting pipe, and the discharge pipe 13 connects to a circulating storage tank.

[0028] Microalgae are cultured in an incubator according to the following steps: Step a: Algal Activation and Scale-up Cultivation. Spirulina and Chlorella were inoculated into culture media for activation and scale-up cultivation. The culture medium for Spirulina was Zarrouk standard medium, and the culture medium for Chlorella was BG-11 medium. The cultivation period was 3-5 days to obtain culture solutions of the two microalgae.

[0029] Step b: Mixed culture. First, the first-stage incubator 2 is cleaned and disinfected. The sterile basic culture medium in the basic culture medium storage tank is injected into the first-stage incubator 2 through the feed pipe 4 and the liquid guide pipe 10. The amount of basic culture medium is half the volume of the incubator. The Spirulina and Chlorella microalgae obtained in step a are inoculated into the first-stage incubator 2. The inoculation ratio of Spirulina to Chlorella is 6:4. The sum of the inoculation amounts of the two algae accounts for 10% (v / v) of the basic culture medium. After aeration and stirring through the air inlet pipe 5, the aeration is stopped and light culture is carried out. The cultivation temperature is 25-35℃. The temperature in the incubator is controlled by a temperature sensor and a heating rod to maintain the cultivation temperature within a suitable range. CO2-rich air is introduced 3-5 times daily through the air inlet pipe. The gas is fully dispersed inside the incubator through a screen, which is beneficial for microalgae absorption and removes oxygen. The incubator is placed outdoors, using a combination of natural and artificial light. Natural light is used during the day, and artificial light at 3000-5000 lx is used for supplemental lighting when sunlight is insufficient (light-dark cycle of 12:12 or 14:10). The incubator provides suitable gas, temperature, and light conditions for the algae. From the second day until the day before harvest, nutrient solution is added to the incubator 1-2 times daily, with the daily amount of supplemental nutrients being 1-5% of the incubator volume (starting with a small amount and gradually increasing). The supplemental nutrient solution is added to the incubator from the supplemental nutrient solution storage tank via the feed pipe 4 and the liquid guide pipe 10. Daily supplementation with selenium-containing nutrient solution can reduce the inhibitory effect of selenium on microalgae compared to a large-dose one-time addition, thereby improving microalgae growth and selenium conversion. Microalgae can be harvested after 7-10 days of cultivation, when they fill the upper and middle parts of the incubator. Selenium supplementation should be stopped 24 hours before harvest to allow the microalgae to fully absorb and convert inorganic selenium into organic selenium, reducing the inorganic selenium content in the wet substrate. In winter, the incubator should be moved indoors, with artificial lighting and auxiliary heating devices provided to ensure adequate temperature and light conditions.

[0030] The basic culture medium is prepared with the following proportions per liter: NaHCO3 8-15g, MgSO4 0.1-0.3g, K2HPO4 0.3-0.5g, NaNO3 1.0-2.5g, NaCl 2-5g, CaCl2 0.2-0.5g, and pH 7.0-8.0. The supplementary culture medium is prepared with the following proportions per liter: NaHCO3 3-5g, sodium selenite 0.3-1.0mg, glucose 0.2g, urea 0.1g, and pH 8.0-9.0. The water used to prepare the culture medium is deep well water or spring water, rich in minerals.

[0031] Chlorella, a green algae, can rapidly absorb inorganic selenium from the culture medium and quickly convert it into organic selenoproteins within its cells. Spirulina (Spirulina platensis), a cyanobacterium, is a photosynthetic autotrophic algae that can accumulate high concentrations of selenium. Spirulina exhibits a "low-promote, high-inhibitory" biological effect. Therefore, Chlorella's rapid absorption of inorganic selenium reduces the selenium content in the culture medium, thereby mitigating the inhibitory effect of selenium on early-stage Spirulina and achieving a synergistic symbiosis between the two microalgae. The microalgae also contain certain amounts of minerals, salts, and baking soda, which are beneficial to the health of dairy goats.

[0032] Step c: Feeding. When harvesting microalgae, open the exhaust pipe. Gas passes through the screen, forming fine bubbles that fill the incubator. Chlorella aggregates into clumps and floats on the surface of the culture medium under the action of the bubbles. The clumps of chlorella and spirulina hyphae intertwine to form a web, facilitating filtration and collection. Reduce the exhaust volume and open the valve on the bottom connecting pipe. The culture medium in the first-stage incubator, after being filtered through the screen, slowly flows out through the connecting pipe, with some entering the second-stage incubator 3 and some entering the circulating storage tank. Microalgae are trapped on the screen surface. A small amount of aeration keeps the screen clear and prevents microalgae from clogging the mesh. When the surface of the culture medium is 5cm above the screen, close the valve. At this point, the microalgae on the screen containing a small amount of culture medium and bubbles are fresh, wet microalgae.

[0033] During feeding, open the top panel 12 of the incubator and place the dairy goats in the harvested incubator. Each goat enters the grid to consume the microalgae wet feed, followed by drinking water. The microalgae wet feed can also be added to the concentrate feed. After feeding, rinse and sterilize the first-stage incubator and sieves, preparing for the next incubation cycle. Feeding microalgae wet feed not only supplements the dairy goats with selenium, calcium, and appropriate amounts of salt and water, improving the quality of goat milk by including organic selenium and calcium, but also benefits from the high activity of organic protein selenium in fresh microalgae, making it easier for the goats to absorb selenium directly. This method also reduces the steps of collecting and drying microalgae, simplifying operations and lowering costs, making it suitable for small to medium-sized free-range farms.

[0034] Step d: Multi-stage continuous culture. In the second-stage incubator, the basal culture medium is mixed with the culture medium from the first-stage incubator at a ratio of 7:3, and the total volume of both media is 60% of the incubator volume. Step b is repeated for microalgae culture. The circulating culture medium contains a small amount of Spirulina, Chlorella, and some nutrients. Spirulina can be added after the second-stage incubator for continued culture. Starting on the third day, a mixture of supplementary culture medium and circulating culture medium is added. Because the algae and nutrients in the previous stage's culture medium combine with the newly formed dominant strain after inoculation, it is beneficial for population growth, prevents contamination by other microorganisms, and, since the original algae are adapted to the selenium-rich culture environment, they can directly absorb and transform nutrients, reducing the culture time to 6-8 days for harvest.

[0035] The culture medium harvested from the second-stage incubator can be used for the next stage of cultivation, thus achieving multi-stage continuous cultivation and a stable supply of algae. Reusing the culture medium reduces costs and the number of sterilization cycles. Furthermore, the reused culture medium contains original microalgae, which promotes rapid algal reproduction and reduces the generation of contaminating bacteria. Example

[0036] The sheep farm in Pingshan County, Hebei Province, has a total of 35 sheep, including 8 pregnant sheep, 10 lactating sheep, 8 recovering sheep, and 6 lambs. The microalgae strains were purchased from Arge Hebei Life Science Co., Ltd., and the components of the culture medium were commercially available. There were 6 outdoor multi-stage incubators and 3 indoor multi-stage incubators, each consisting of 2 or 3 incubators connected in series. Microalgae were cultivated in the incubators. The experimental group consisted of 4 pregnant sheep and 7 lactating sheep, while the control group consisted of 4 pregnant sheep and 3 lactating sheep. The experimental group was fed wet microalgae feed daily in the incubators, while the control group was not fed wet microalgae feed; all other feeding conditions were the same.

[0037] Spirulina and Chlorella were used as microalgae. The two microalgae species were activated and cultured separately in culture media for 3 days. The first-stage incubator in a multi-stage incubator was cleaned. 400L of sterilized basal culture medium was prepared and poured into the first-stage incubator. Spirulina and Chlorella culture media were then inoculated. From the second day after inoculation until the day before harvest, sterilized supplemental culture medium with a sodium selenite concentration of 0.5mg / L was added daily. Initially, 10L of supplemental culture medium was added in two divided doses, gradually increasing to 40L / day over 5-6 days. Natural light was used during the day, supplemented with artificial light when sunlight was insufficient, using a mixed light cultivation method. During the cultivation period, carbon dioxide-rich air was introduced and stirred 2-3 times daily. After 9 days of cultivation, the microalgae grew densely, filling the cultivation tank. At harvest, the air inlet pipe was opened to allow the Chlorella to float and clump together. The air intake was reduced, and the valve on the connecting pipe was opened. Part of the culture solution flowed out through the connecting pipe into the second-stage cultivation tank, and the other part into the circulating storage tank. The microalgae were trapped on the screen in the first-stage cultivation tank. 6.5 kg of fresh wet microalgae substrate was harvested, and the selenium content in the wet microalgae substrate was found to be 2.3 mg / kg.

[0038] Add 200L of basal culture medium and 200L of culture medium from the first-stage incubator to the second-stage incubator, inoculate with Spirulina culture, and continue microalgae culture according to the above steps.

[0039] The top panel of the first-stage incubator was opened. Pregnant and lactating goats gathered around the incubator, each entering its designated grid to feed on the microalgae-rich wet feed on the screen, followed by drinking water. The goats were fed microalgae daily during lactation, and milk was collected 8 hours after feeding. Milk quality was tested, and the results are shown in Table 1. The presence of organic selenium and other nutrients in the goat milk improved the quality of the fresh milk. After feeding, the incubator and screen were rinsed and sterilized, ready for re-culturing.

[0040] Table 1. Comparison of sheep condition and milk quality between sheep fed microalgae and the control group. Production status Recovery is rapid after childbirth; milk production can resume normally within 2-3 days postpartum. Recovery after childbirth is relatively slow; normal milk production resumes 4-5 days postpartum. Milk production status The average daily milk production is 2.5 L per animal, with a breast disease incidence rate of 5%. Average daily milk production: 2.0 L / bird; incidence of breast disease: 20%. Selenium content 0.19 mg / kg (organic selenium ≥ 85%) 0.03 mg / kg (mainly inorganic selenium) Calcium content 1380mg / kg 1200mg / kg milk protein content 4.2% 3.6% Milk fat content 3.5% 3.1% Coat color and body condition Glossy coat and in good condition. In winter, their coat color is dull and their body condition is average. dairy goat immunity The incidence rate is low throughout the year, and common diseases such as diarrhea rarely occur. People are prone to illness in winter, and diarrhea occasionally occurs. The results show that the experimental group of dairy goats fed microalgae wet feed experienced a 25% increase in milk production, a 16.7% increase in milk fat content, and a 12.9% increase in milk protein content. The organic selenium content in the goat milk was significantly increased, reaching 0.19 mg / kg, meeting the daily selenium requirement for adults. The recommended daily intake for adults is 30-60 μg, and drinking 250 mL of this goat milk can supplement 47 μg of selenium, accounting for 70%-100% of the recommended intake, which is within the safe upper limit. The goats also showed enhanced immunity, with a significant reduction in the incidence of common diseases such as diarrhea and mastitis. Therefore, the selenium, calcium, and other minerals in the microalgae wet feed enhance the nutritional value of goat milk.

Claims

1. A method for raising dairy goats, characterized in that, The feed for dairy goats includes roughage, concentrate, and selenium supplements. During the growth and recovery periods, dairy goats are routinely fed roughage and concentrate according to the seasons. During pregnancy and lactation, roughage is reduced, concentrate is increased, and selenium supplements are added. The concentrate includes corn, soybean meal, wheat bran, and trace elements. The trace elements include compound vitamins, salts, and calcium supplements. The selenium supplement is fresh microalgae wet feed rich in organic selenium. The calcium supplement includes one or more of dicalcium phosphate, bone meal, and tofu residue.

2. The method for feeding dairy goats according to claim 1, characterized in that, The roughage includes one or more of the following: grain straw, alfalfa, peanut vines, or stems and leaves of leguminous plants. The roughage is cut into small pieces. The proportions of each component of the concentrate during pregnancy and lactation are as follows by weight: 55-60 parts corn, 30 parts soybean meal, 5 parts wheat bran, and 5-10 parts trace elements, of which 3-5 parts are calcium preparations. During pregnancy, feed 200-400g of fresh microalgae wet feed per animal per day, and during lactation, feed 400-600g per animal per day.

3. The method for feeding dairy goats according to claim 2, characterized in that, The microalgae consist of Spirulina and Chlorella. Spirulina and Chlorella are cultured in a selenium-containing medium to obtain wet microalgae feed. Dairy goats in the lactation period are fed fresh wet microalgae feed every day, and milk is taken after 8 hours of feeding to obtain fresh goat milk containing organic selenium.

4. The method for feeding dairy goats according to claim 3, characterized in that, The microalgae are cultivated in a cultivation device located in a dairy goat farm. The cultivation device includes a cultivation box, a basic culture medium storage tank, a supplementary culture medium storage tank, a circulation tank, and a feed pipe (4). Each storage tank is connected to the cultivation box through the feed pipe (4). The cultivation box is a space composed of an upper cuboid and a lower inverted triangle. A top plate (12) is movably installed on the top of the cultivation box, and several ventilation holes (9) are opened on the top plate. A liquid guide pipe (10) is installed on the upper part of the cultivation box. A screen (8) is installed on the lower part of the cultivation box, and the frame of the screen abuts against the wall of the cultivation box. An air inlet pipe (5) and a heating rod (7) are installed below the screen (8). A discharge port is installed at the bottom of the cultivation box.

5. The method for feeding dairy goats according to claim 4, characterized in that, The incubator is a multi-stage incubator connected in series. A connecting pipe (6) is provided between adjacent incubators. The discharge port of the upper-stage incubator is connected to one end of the connecting pipe (6), and the other end of the connecting pipe (6) is connected to the liquid guide pipe (10) of the lower-stage incubator. A discharge pipe (13) is provided on the connecting pipe (6), and the discharge pipe (13) is connected to the circulating storage tank.

6. The method for feeding dairy goats according to claim 5, characterized in that, The microalgae are cultured in an incubator, including the following steps: a. Algal strain activation and scale-up culture: Spirulina and Chlorella strains were inoculated into activation medium for activation and scale-up culture for 3-5 days to obtain algal culture solutions of the two microalgae. b. Mixed culture: Inject the basic culture medium from the basic culture medium storage tank into the first-stage culture box, and inoculate the Spirulina and Chlorella seeds obtained in step a into the first-stage culture box. Aerate and stir through the air inlet pipe (5) for light culture. From the second day after inoculation to the day before harvest, add supplementary culture medium from the supplementary culture medium storage tank to the first-stage culture box every day. The amount added is 1-5% of the culture box volume. After 7-10 days of culture, it can be harvested. Open the valve of the connecting pipe, and the culture medium in the first-stage culture box is discharged after being filtered through the screen. c. Feeding: Microalgae in the first-stage incubator are intercepted on the surface of the screen (8); open the top plate (12) of the incubator and feed the dairy goats with wet microalgae feed around the incubator; d. Continuous cyclic culture: Add basic culture medium to the second-stage incubator, inoculate with Spirulina inoculum, and repeat step b for microalgae culture to achieve continuous and stable algae supply.

7. The method for feeding dairy goats according to claim 6, characterized in that, The supplementary culture medium is prepared with the following components per liter: 3-5g NaHCO3, 0.3-1.0mg sodium selenite, 0.2g glucose, and 0.1g urea, with a pH of 8.0-9.0; the water used to prepare the culture medium is deep well water or spring water.

8. The method for feeding dairy goats according to claim 6, characterized in that, In step b, the exhaust pipe is opened to allow gas to pass through the screen and form fine bubbles, causing the microalgae to float and clump together on the surface of the culture medium. The exhaust volume is reduced and the valve of the bottom connecting pipe is opened. The culture medium in the first-stage incubator is filtered through the screen and slowly flows out from the connecting pipe. Part of it enters the next-stage incubator and part of it enters the circulating storage tank. The microalgae are intercepted on the surface of the screen. The microalgae on the screen are fresh wet microalgae material.

9. The method for feeding dairy goats according to claim 8, characterized in that, In step d, the ratio of the basic culture medium in the second-stage incubator to the culture medium in the first-stage incubator is 7:

3. From the third day after inoculation until the day before harvest, a mixture of supplementary culture medium and circulating culture medium is added daily, and the culture is carried out for 6-8 days before harvest.

10. A type of fresh goat milk, characterized in that, The fresh goat milk obtained by the method of feeding dairy goats according to any one of claims 1-9 has an organic selenium content of 0.10-0.30 mg / kg and a calcium content of 1200-1400 mg / kg.

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