Yak feed obtained through microbial fermentation and preparation method thereof

Abstract

The invention belongs to the technical field of fermented feeds, provides a yak feed obtained through microbial fermentation, particularly relates to a yak feed obtained through bacillus velezensis fermentation, and further relates to a preparation method of the yak feed. In the application, after bacillus velezensis K24 is inoculated and cultured, the obtained fermentation liquor is directly inoculated into the raw feed of the yak feed, and fermentation culture is performed, so that the fermented feed is obtained. Compared with common feed before fermentation, the yak feed provided by the invention can significantly improve daily gain and disease resistance of yaks.

Description

Technical Field

[0001] The invention belongs to the technical field of fermented feed, and particularly relates to a yak feed obtained by microbial fermentation, in particular to a yak feed obtained by fermentation with Bacillus velez, and also relates to a preparation method of the feed. Background Art

[0002] Yaks are mostly grown in the plateau area. The temperature in the plateau area is low, the oxygen is thin, and their growth and development are slower than those of cattle in other areas. In addition, the supply and demand of forage grass is seasonally unbalanced and cannot meet the nutritional needs of yaks for growth. Existing yak feeds are mostly made of highland barley, straw or forage grass, supplemented with other feeds such as corn flour, rapeseed cake, soybean meal, etc., and then added with baking soda, fattening cattle multivitamin, Vinomycin multi-mineral, compound probiotics, etc., to improve the resistance of cattle, fatten quickly, and improve breeding efficiency.

[0003] Literature on yak feed discloses that rapeseed straw, forage grass, fermentation liquid, etc. are used as raw materials. The straw is steam-exploded, then enzymatically hydrolyzed with cellulase, and the enzymatic liquid is then mixed with other raw materials to obtain yak feed that is rich in nutrients and has greatly improved taste.

[0004] There are also documents that disclose that feed is prepared using ryegrass, highland barley, turnip, soybean meal, wheat bran, isatis root, and purple daisy as raw materials through fermentation with yeast, Bacillus subtilis, Bifidobacterium, etc.

[0005] The inventors searched and found that there is no disclosure of the relevant scheme for applying Bacillus Velez subtilis to yak feed. Summary of the invention

[0006] The present invention is to solve the above technical problems. In the present invention, Bacillus Velezii is applied to the preparation of fermented feed for yaks in plateau areas. The obtained fermented feed can significantly improve the daily weight gain and disease resistance of yaks compared with ordinary feed before fermentation.

[0007] The key protection of the present invention is the use of Bacillus velezensis K24 in the preparation of yak feed. The above-mentioned Bacillus velezensis K24 is classified as Bacillus velezensis, deposited in Guangdong Microbiological Culture Collection Center, with a deposit number of GDMCC NO.64095, a deposit date of December 1, 2023, and a deposit address: Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0008] Specifically, in the above application, after inoculating and culturing Bacillus Velez K24, the obtained fermentation liquid is directly added to yak raw feed (i.e., ordinary feed for feeding yaks, which has not been fermented, hereinafter referred to as "yak raw feed") for fermentation and culture, thereby obtaining fermented feed.

[0009] The above-mentioned yak feed contains:

[0010] Roughage: corn straw 20-30, wheat straw 10-20, bean straw 10-20, highland barley straw 50-70;

[0011] Concentrated feed: cornmeal 10-20, rice bran 20-30, soybean cake 10-20, rapeseed cake 15-25, sea buckthorn seed meal 15-30, highland barley grains 20-30.

[0012] More specifically, the activated Bacillus Velezii K24 is inoculated into a culture medium, and fermented and cultured at 35 to 38° C. for 16 to 30 hours to obtain a fermentation liquid;

[0013] The culture medium is: glucose 20g / L; yeast extract 20g / L; peptone 16g / L; MgSO4·7H2O0.5g / L; sorbitol 10g / L, FeSO4·7H2O 1.2g / L;

[0014] Add the fermentation liquid to the original yak feed at a liquid-to-solid ratio of 0.2-0.4:1, mix evenly, and ferment at 35-38°C for 36-60 hours.

[0015] The present invention also intends to protect the yak feed obtained by fermentation of the above-mentioned microbial strain Bacillus Velez K24. The feed is prepared by fermentation of Bacillus Velez K24. Preferably, the above-mentioned yak feed raw material comprises the following raw materials in parts by weight:

[0016] Roughage: corn straw 25, wheat straw 16, bean straw 18, highland barley straw 60;

[0017] Concentrated feed: corn flour 18, rice bran 24, soybean cake 16, rapeseed cake 22, sea buckthorn seed meal 24, and highland barley grains 25.

[0018] Compared with the prior art, the present invention has the following advantages and effects:

[0019] (1) The present invention significantly increases the daily weight gain of yaks by applying Bacillus Velez K24 to yak feed, with an average daily weight gain of up to 0.731 kg / d, which helps to accelerate the growth rate of yaks and improve breeding efficiency;

[0020] (2) Compared with traditional technologies, the yak feed provided by the present invention can significantly improve the disease resistance of yaks, thereby reducing the occurrence of diseases, reducing medical costs in the breeding process, and ensuring the health of yaks. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0022] Example 1

[0023] The method for preparing yak feed by fermenting Bacillus Velez K24 comprises the following steps:

[0024] (1) activating and culturing Bacillus velezensis K24, the strain Bacillus velezensis K24 is classified as Bacillus velezensis and is deposited in Guangdong Microbiological Culture Collection Center with a deposit number of GDMCC NO.64095;

[0025] Prepare culture medium: glucose 20 g / L; yeast extract 20 g / L; peptone 16 g / L; MgSO4·7H2O 0.5 g / L; sorbitol 10 g / L, FeSO4·7H2O 1.2 g / L.

[0026] Use cotton wool soaked in 75% alcohol to clean the wall of the culture tube to remove possible contaminants on the surface. Use a file or tweezers to gently tap the top of the cracked culture tube. Use a sterile pipette to absorb about 0.5 mL of liquid culture medium and drop it into the culture tube. Gently shake the culture tube to fully dissolve the freeze-dried bacteria into a suspended liquid.

[0027] Use a sterile inoculation loop to take the above suspended bacterial suspension and streak inoculate on the slant. At the same time, pour the remaining bacterial suspension into the culture medium for cultivation.

[0028] The inoculated solid and liquid culture media are placed under growth conditions suitable for the strain for cultivation.

[0029] (2) Prepare yak raw feed

[0030] Roughage: corn straw 25, wheat straw 16, bean straw 18, highland barley straw 60;

[0031] Concentrated feed: cornmeal 18, rice bran 24, soybean cake 16, rapeseed cake 22, sea buckthorn seed meal 24, highland barley grains 25;

[0032] (3) Take the Bacillus Velez K24 cultured in (1), inoculate it into the original yak feed at an inoculum rate of 3%, mix well, and ferment at 37° C. for 48 hours.

[0033] The difference between Examples 2 to 6 and Example 1 is that the amount (weight parts) of the original yak feed is different, as follows:

[0034] Table 1 Amount of raw yak feed in Examples 1 to 6

[0035] -- Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Corn stalks 25 20 30 22 28 26 Wheat straw 16 10 20 15 18 12 Bean straw 18 10 20 14 12 16 Highland barley straw 60 50 70 55 65 62 Cornmeal 18 10 20 12 14 17 Rice bran 24 20 30 24 26 23 cake 16 10 20 12 15 16 Rapeseed Cake 22 16 18 15 25 24 Sea buckthorn seed meal 24 15 30 24 22 28 Highland barley grains 25 20 30 24 26 25

[0036] The other steps in Examples 2-6 are the same as in Example 1.

[0037] Example 7

[0038] 1 Materials and methods

[0039] 1.1 Yak

[0040] Yaks around 2 years old, healthy and in similar physical condition were selected, half male and half female, and randomly divided into four groups, with 10 yaks in each group.

[0041] 1.2 Feed

[0042] The blank group was fed with unfermented feed;

[0043] The control group was fed with feed fermented by commercially available Bacillus Velez subtilis, and the fermentation process, feed raw materials and proportions thereof were referred to Example 1 of the present invention;

[0044] The test groups were divided into test group 1, test group 2, test group 3, test group 4, test group 5 and test group 6, which were fed with yak feed obtained by fermentation in Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6 of the present invention, respectively.

[0045] 1.3 Test methods

[0046] The experimental period was 90 days. During the experiment, each group of yaks were fed in a shed, fed from 14:00 to 15:00 every afternoon, had free drinking water, and cleaned the shed regularly to keep the feeding environment clean. During the experimental period, the amount of feed was gradually increased according to the yak's feeding situation. Among them, the amount of feed for yaks was adjusted according to the actual feed intake and gradually increased from 12.5kg / d to 20kg / d.

[0047] 1.4 Measurement indicators and methods

[0048] (1) Before and after feeding, the yaks were weighed and the data were recorded. During the experiment, the feed intake of each group of yaks was recorded, and the total weight gain and average daily weight gain were calculated.

[0049] Average daily weight gain = (final weight - initial weight) / number of test days.

[0050] Table 2 Growth and disease status of yaks fed with different feeds

[0051]

[0052] As can be seen from Table 2, there was basically no difference in the initial weight between the control group and the experimental group, but with the increase in feeding time, the daily weight gain of the experimental group and the control group increased significantly compared with the blank group. The daily weight gain of the experimental group 1 was 0.842 kg, and the daily weight gain of the experimental group 2 was 0.682 kg, both of which were much higher than the daily weight gain of the control group of 0.487 kg. It can be seen that the feed obtained by fermentation with Bacillus Velez K24 can significantly promote the growth of yaks, and the effect is far better than the feed obtained by fermentation with Bacillus Velez on the market.

[0053] (2) The MTT method was used to measure the lymphocyte proliferation rate of yaks before feeding and after feeding for 15d, 30d, 45d, 60d, and 90d.

[0054] Table 3 Lymphocyte proliferation rate (SI value)

[0055]

[0056] It can be seen from Table 3 that the lymphocyte proliferation rate of the test group is significantly improved than that of the control group, that is, after feeding the yaks with the feed obtained by fermentation of the present invention, their cellular immune function can be improved, thereby improving the disease resistance of the yaks, and the effect is better than that of the control group. The yak disease data in Table 2 also confirms this view from the side.

Claims

1. Application of Bacillus Velez K24 in preparing yak feed, characterized in that: The classification name of the Bacillus Velezii K24 is Bacillus velezensis , deposited in Guangdong Microbiological Culture Collection Center with the deposit number GDMCCNO.64095.

2. The use according to claim 1, characterized in that After inoculating and culturing Bacillus Velez subtilis K24, the obtained fermentation liquid is directly inoculated into the original feed of yak feed for fermentation and culture, thereby obtaining fermented feed.

3. The use according to claim 2, characterized in that The raw yak feed contains: Roughage: corn straw 20-30, wheat straw 10-20, bean straw 10-20, highland barley straw 50-70; Concentrated feed: cornmeal 10-20, rice bran 20-30, soybean cake 10-20, rapeseed cake 15-25, sea buckthorn seed meal 15-30, highland barley grains 20-30.

4. The use according to claim 2, characterized in that The activated Bacillus Velezii K24 was inoculated into the culture medium, and fermented and cultured at 35-38°C for 16-30 hours to obtain a fermentation liquid; The culture medium is: glucose 20g / L; yeast extract 20g / L; peptone 16g / L; MgSO4·7H2O 0.5 g / L; sorbitol 10 g / L, FeSO4·7H2O 1.2 g / L; Add the fermentation liquid to the original yak feed at a liquid-to-solid ratio of 0.2-0.4:1, mix evenly, and let it ferment at 35-38°C for 36-60 hours.

5. Yak feed obtained by microbial fermentation, characterized in that: The feed is prepared by fermentation of Bacillus Velezii K24. Bacillus velezensis , deposited in Guangdong Microbiological Culture Collection Center, with the deposit number GDMCC NO.64095; The raw yak feed comprises the following raw materials in parts by weight: Roughage: corn straw 20-30, wheat straw 10-20, bean straw 10-20, highland barley straw 50-70; Concentrated feed: cornmeal 10-20, rice bran 20-30, soybean cake 10-20, rapeseed cake 15-25, sea buckthorn seed meal 15-30, highland barley grains 20-30; After activating and culturing Bacillus Velezii K24, the fermentation liquid is inoculated into the original yak feed, and fermented to obtain the fermented feed.

6. The yak feed obtained by microbial fermentation according to claim 5, characterized in that: The feed comprises the following raw materials in parts by weight: Roughage: corn straw 25, wheat straw 16, bean straw 18, highland barley straw 60; Concentrated feed: cornmeal 18, rice bran 24, soybean cake 16, rapeseed cake 22, sea buckthorn seed meal 24, and highland barley grains 25.

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