Yeast culture for feeding ruminants as well as preparation method and application of yeast culture

Abstract

The invention provides a yeast culture for feeding ruminants as well as a preparation method and application of the yeast culture. The preparation method comprises the following steps: mixing a fermentation raw material, a yeast additive, a fermentation inoculant and a compound enzyme agent, and fermenting to obtain a yeast culture; the yeast additive comprises yeast hydrolysate, yeast metabolite or yeast cell wall; the fermentation inoculant comprises one or more of saccharomycetes, lactic acid bacteria or spore bacteria; the fermentation raw materials comprise a fermentation carbon source and a fermentation nitrogen source; the fermentation carbon source comprises corn flour and bran; the fermentation nitrogen source comprises soybean meal, miscellaneous meal and DDGS. The ruminant yeast culture can solve the problem that the ruminant yeast culture in the prior art cannot meet the nutritional requirements of animals and provide yeast functions at the same time, and is suitable for the field of ruminant feeding.

Description

Technical Field

[0001] The invention relates to the field of ruminant breeding, and in particular to a yeast culture for ruminant breeding, and a preparation method and application thereof. Background Art

[0002] In recent years, with the rapid development of bioengineering technology and modern animal nutrition, fermented feed, as a new type of feed product, has gradually emerged in the terminal market of mutton and cattle. This type of feed is mainly made of agricultural and sideline products such as crop straw, amino acid residue, apple residue, bean dregs, and defective fruits as substrates, and is fermented by bacterial enzymes. The raw material cost of this type of feed is low, which improves the utilization rate of the above low-value agricultural and sideline products. It is generally used to replace some expensive ruminant concentrates, and the amount added to the feed of mutton and cattle is 5-10% to reduce the overall feeding cost. However, these fermented feeds usually focus on improving the palatability of ruminants and the substitutability for concentrates, and often pay less attention to the impact on the overall nutritional level of animals. In fact, it is difficult to meet the nutritional needs of ruminants.

[0003] Yeast and its metabolites can improve the rumen health of ruminants, enhance stress resistance, promote digestion, reduce the risk of diarrhea, and improve production performance. The existing technology usually uses yeast and yeast metabolites to prepare fermented feed. However, in the process of preparing yeast culture, the existing technology is prone to problems such as large-scale inactivation of bacterial enzymes, loss of many beneficial bioactive substances and flavor substances, which reduces the nutritional and functional characteristics of the fermented feed itself. It is difficult to replace concentrated supplements in the diet of ruminants, and can only be supplemented in the diet of ruminants as an additive.

[0004] Therefore, it is particularly important to design a new yeast culture that can match the ruminant feed in terms of substrate nutrition, live bacteria and metabolites. This culture should have high live bacteria retention, rich metabolites, and provide balanced substrate nutrition to improve the rumen health of ruminants, promote feeding and digestion, strengthen immunity, and improve the production performance and economic benefits of cattle and sheep. Summary of the invention

[0005] The main purpose of the present invention is to provide a yeast culture for feeding ruminants and a preparation method and application thereof, so as to solve the problem in the prior art that the yeast culture of ruminants cannot simultaneously meet the nutritional needs of the animals and provide yeast functions.

[0006] In order to achieve the above-mentioned object, according to a first aspect of the present invention, there is provided a method for preparing a yeast culture for feeding ruminants, the method comprising: mixing a fermentation raw material, a yeast additive, a fermentation agent and a composite enzyme agent and then fermenting to obtain a yeast culture; the yeast additive comprises yeast hydrolyzate, yeast metabolite or yeast cell wall; the fermentation agent comprises: one or more of yeast, lactic acid bacteria or spore-forming bacteria; the addition amount of the yeast additive comprises 1-5 parts of yeast hydrolyzate, 1-10 parts of yeast metabolite and 1-5 parts of yeast cell wall; the fermentation raw material comprises a fermentation carbon source and a fermentation nitrogen source; the fermentation carbon source comprises corn flour and bran; the fermentation nitrogen source comprises one or more of soybean meal, miscellaneous meal or DDGS.

[0007] Furthermore, the complex enzyme comprises: one or more of protease, cellulase, xylanase, glucanase, saccharification enzyme or α-amylase. Preferably, the miscellaneous meal comprises one or more of corn germ meal, rice bran meal, peanut meal, rapeseed meal, sunflower meal, palm meal, cottonseed meal, sesame meal or flax meal.

[0008] Further, the yeast includes one or more of Saccharomyces cerevisiae, Candida utilis or Kluyveromyces marxianus; the lactic acid bacteria include one or more of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus buchneri, Lactobacillus paracasei, Lactobacillus acidophilus, Pediococcus acidilactici, Enterococcus faecalis or Enterococcus faecium; the spore-forming bacteria include one or more of Bacillus subtilis, Bacillus licheniformis, Bacillus coagulans or Brevibacillus laterosporus; preferably, the yeast is yeast powder, the lactic acid bacteria is lactic acid bacteria powder, and the spore-forming bacteria is spore-forming bacteria powder; preferably, the number of live bacteria in the yeast powder is 50-300 billion cfu / g; preferably, the number of live bacteria in the lactic acid bacteria powder is 100-100 billion cfu / g; preferably, the number of live bacteria in the spore-forming bacteria powder is 100-100 billion cfu / g.

[0009] Furthermore, the activity of protease is 50,000-300,000 U / g, the activity of cellulase is 5,000-100,000 U / g, the activity of xylanase is 5,000-100,000 U / g, the activity of glucanase is 5,000-100,000 U / g, the activity of saccharifying enzyme is 5,000-200,000 U / g, and the activity of α-amylase is 10,000-300,000 U / g.

[0010] Furthermore, calculated by weight, the added amount of fermentation bacteria includes one or more of 0.1-3 parts of yeast, 0.1-3 parts of lactic acid bacteria or 0.1-3 parts of spore-forming bacteria; the added amount of complex enzyme agent is 0.1-3 parts; the added amount of fermentation raw materials is 45-140 parts; the fermentation raw materials include 10-40 parts of corn flour, 10-35 parts of DDGS, 10-25 parts of bran, 10-20 parts of miscellaneous meal and 5-20 parts of soybean meal.

[0011] Furthermore, the fermentation temperature is 25-35° C.; preferably, the fermentation time is 3-5 days.

[0012] Furthermore, the fermentation system also contains water, and the mass of the water accounts for 30-40% of the total mass of the fermentation system.

[0013] In order to achieve the above object, according to a second aspect of the present invention, a yeast culture for feeding ruminants is provided, wherein the yeast culture is prepared by the above method for preparing the yeast culture for feeding ruminants;

[0014] The contents of the components in the yeast culture, measured on a dry matter basis, include: crude protein ≥ 20wt%, acid-soluble protein in crude protein ≥ 30%, crude ash ≤ 10wt%, crude fiber ≤ 7wt%, lactic acid ≥ 2wt%, and mannan ≥ 2wt%; the number of live yeast cells in the yeast culture ≥ 1×10 7 CFU / g, viable lactic acid bacteria count ≥ 1×10 8 CFU / g.

[0015] Further, the yeast culture contains flavor substances; the flavor substances include one or more of alcohols, esters, acids, ketones, aldehydes or azine; preferably, the alcohol includes one or more of phenylethyl alcohol, isopentanol, n-hexanol, 2,3-butanediol or furfuryl alcohol; preferably, the ester includes one or more of ethyl hexanoate, 2-phenylethyl hexanoate, ethyl valerate, diethyl succinate, ethyl caprylate, ethyl laurate, ethyl nonanoate, ethyl butyrate, ethyl benzoate or ethyl palmitate; preferably, the ketone includes 3-hydroxy-2-butanone; preferably, the azine includes one or more of 2,3-dimethyl-5-ethylpyrazine, ligustrazine, 2-ethyl-6-methylpyrazine or 2,3,5-trimethylpyrazine; preferably, the alcohol accounts for 30-35% of the total mass of the flavor substances, and the ester accounts for 40-45% of the total mass of the flavor substances; preferably, phenylethyl alcohol accounts for 20-25% of the total mass of the flavor substances.

[0016] In order to achieve the above object, according to a third aspect of the present invention, a method for preparing a yeast culture for ruminant feeding or use of the yeast culture for ruminant feeding in ruminant feeding is provided.

[0017] Furthermore, the application includes: mixing yeast culture, concentrated supplement for ruminants and roughage for ruminants to obtain a ruminant diet, and feeding the ruminants; the addition amount of yeast culture accounts for 5-20% of the total weight of the ruminant diet.

[0018] The technical scheme of the present invention is applied, and the yeast culture of the present application is obtained by mixing a fermentation carbon source, a yeast additive, a fermentation agent, and a complex enzyme agent for fermentation, wherein the yeast additive includes one or more of yeast hydrolyzate, yeast metabolite, or yeast cell wall, and the fermentation agent includes one or more of yeast, lactic acid bacteria, or spore-forming bacteria. The yeast culture of the present application has a high number of live bacteria, is rich in nutrition, can retain the components in yeast metabolites, can replace part of the concentrate supplement and be mixed in the diet of ruminants, and helps to improve the rumen health of ruminants and improve production performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic diagram showing the flavor substance composition of the yeast culture of Test Example 2 of the present invention is shown.

[0021] Figure 2 A schematic diagram showing nutritional indexes and microbial indexes of the yeast culture of Test Example 3 of the present invention is shown. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0023] Terminology explanation:

[0024] Yeast metabolites: fermentation metabolites of yeast cultured with molasses, refined through concentration and other processes to produce yeast metabolites products rich in amino acids, organic acids, fulvic acid, polysaccharides and other substances as well as major, medium and trace elements.

[0025] Yeast culture: refers to a microecological product formed by sufficient anaerobic fermentation of yeast on a specific culture medium under specific process conditions. It is mainly composed of yeast extracellular metabolites, culture medium that has mutated after fermentation, and a small amount of inactive yeast cells.

[0026] Concentrated feed: refers to feed that provides animals with essential nutrients, usually including energy, protein, vitamins and minerals, etc. This type of feed is usually finely processed, easy for animals to digest and absorb, and can meet the nutritional needs of animals at specific growth stages or production conditions.

[0027] Roughage: Roughage refers to feed with high fiber content and relatively low nutritional value. This type of feed is usually not easy to be digested and absorbed by animals, but it can provide animals with the necessary crude fiber, which helps to maintain the health of the animal's digestive system. It is relatively low in cost and is the main feed source for ruminants. Roughage and concentrate supplements form the basic diet. The ratio of roughage and concentrate supplements in the basic diet is adjusted according to the growth status of the animal. For example, during the fattening transition period of fat sheep, the concentrate-roughage ratio will be adjusted from 5:5 to 7:3.

[0028] Additives: Additives in feed refer to a small amount of substances added to the feed (usually 0-5% of the total weight of the animal's daily diet) to improve feed utilization efficiency, production performance or improve feed preservation characteristics.

[0029] Flavor substances: Flavor substances in feed refer to compounds that can improve the taste of feed and give the feed a characteristic flavor.

[0030] Ruminants: refers to a type of mammals with a special digestive system that can digest food by ruminating, mainly including: cattle, sheep, deer, camels and giraffes.

[0031] As mentioned in the background technology, the yeast culture in the prior art is difficult to balance the relationship between nutrients and live bacteria such as yeast, and cannot simultaneously meet the nutritional needs of animals and provide yeast functions. Therefore, in the present application, the inventors attempt to develop a new method for preparing yeast culture for ruminant feeding. The prepared yeast culture has a high number of live bacteria, is rich in nutrients, and can retain the components of yeast metabolites, which helps to improve the rumen health of ruminants and improve production performance. Based on this, a series of protection schemes of the present application are proposed.

[0032] In a first typical embodiment of the present application, a method for preparing a yeast culture for ruminant feeding is provided, the method comprising: mixing a fermentation raw material, a yeast additive, a fermentation agent and a composite enzyme agent and fermenting to obtain a yeast culture; the yeast additive comprises a yeast hydrolyzate, a yeast metabolite or a yeast cell wall; the fermentation agent comprises: one or more of yeast, lactic acid bacteria or spore bacteria; the composite enzyme agent comprises: one or more of protease, cellulase, xylanase, glucanase, saccharification enzyme or α-amylase; the amount of the yeast additive added comprises 1-5 parts (including but not limited to 1, 2, 3, 4 or 5 parts) of yeast hydrolyzate, 1-10 parts (including but not limited to 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts) of yeast metabolites and 1-5 parts (including but not limited to 1, 2, 3, 4 or 5 parts) of yeast cell walls. The composite enzyme is preferably a protease and a cellulase.

[0033] The basic diet of ruminants is a mixture of concentrated supplements and roughage. Usually, additives are added to the basic diet according to the different growth and development stages of ruminants to improve feed utilization efficiency, production performance or improve feed preservation characteristics, etc. Since concentrated supplements concentrate the nutritional needs of ruminants, the cost of traditional concentrated supplements is relatively high. Therefore, the fermented feed mentioned in the background technology is often used to replace part of the concentrated supplements to reduce the feeding cost.

[0034] However, traditional fermented feeds are mainly used to increase the nutritional utilization of agricultural and sideline products and improve the palatability of animals, and often pay less attention to the nutritional needs of ruminants. Therefore, when they are used as concentrated supplements together with roughage as the basic daily diet for ruminants, it is difficult to meet the overall nutritional needs of ruminants. In addition, they contain fewer active ingredients and have little effect on improving the rumen health of ruminants.

[0035] Since yeast and its metabolites can improve the rumen health of ruminants, enhance stress resistance, promote digestion, reduce the risk of diarrhea, and improve production performance, the prior art has begun to use yeast and its metabolites as the main ingredients to prepare fermented feed. However, the process flow of preparing fermented feed mainly based on yeast can easily lead to the loss of active ingredients and flavor substances of yeast, resulting in low yeast functional components and low nutritional content in the final yeast culture, making it difficult to replace refined feed, and usually can only be used as an additive to the basic diet of ruminants. Therefore, the prior art lacks a yeast culture fermented feed that is mainly based on yeast and can replace refined feed to meet the nutritional needs of ruminants.

[0036] By using the method for preparing yeast culture for ruminant feeding of the present application, a large number of live bacteria can be retained in the prepared yeast culture, and the yeast additive of the present application includes yeast hydrolyzate, yeast metabolites or yeast cell walls, which are enriched with a variety of yeast functional components. Through bacterial and enzyme synergistic fermentation and wet vacuum preservation, active ingredients such as live bacteria, enzymes and flavor substances are retained, and the nutritional value is balanced and rich. The protein, amino acids, and energy-level conventional mineral elements can match the concentrated supplements of ruminants, meet the nutritional needs of ruminants, improve their rumen health, enhance their anti-stress ability and immunity, promote feeding and digestion, and improve the production performance of ruminants.

[0037] In a preferred embodiment, the fermentation raw materials include a fermentation carbon source and a fermentation nitrogen source; preferably, the fermentation carbon source includes corn flour and bran; the fermentation nitrogen source includes one or more of DDGS (dry distiller's grains and solubles, corn DDGS in this application), miscellaneous meal or soybean meal; preferably, the miscellaneous meal includes one or more of corn germ meal, rice bran meal, peanut meal, rapeseed meal, sunflower meal, palm meal, cottonseed meal, sesame meal or flax meal.

[0038] In a preferred embodiment, the yeast comprises one or more of Saccharomyces cerevisiae, Candida utilis or Kluyveromyces marxianus, more preferably Saccharomyces cerevisiae; the lactic acid bacteria comprises one or more of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus buchneri, Lactobacillus paracasei, Lactobacillus acidophilus, Pediococcus acidilactici, Enterococcus faecalis or Enterococcus faecium, more preferably Lactobacillus plantarum; the spore bacteria comprises one or more of Bacillus subtilis, Bacillus licheniformis, Bacillus coagulans or Brevibacillus laterosporus; preferably Preferably, the yeast is yeast powder, the lactic acid bacteria is lactic acid bacteria powder, and the spore bacteria is spore bacteria powder; preferably, the number of live bacteria of the yeast powder is 50-300 billion cfu / g; preferably, the number of live bacteria of the lactic acid bacteria powder is 100-100 billion cfu / g; preferably, the number of live bacteria of the spore bacteria powder is 100-100 billion cfu / g; preferably, the miscellaneous meal includes one or more of corn germ meal, rice bran meal, peanut meal, rapeseed meal, sunflower meal, palm meal, cottonseed meal, sesame meal or flax meal.

[0039] In a preferred embodiment, the activity of protease is 50,000-300,000 U / g, the activity of cellulase is 5,000-100,000 U / g, the activity of xylanase is 5,000-100,000 U / g, the activity of glucanase is 5,000-100,000 U / g, the activity of saccharification enzyme is 5,000-200,000 U / g, and the activity of α-amylase is 10,000-300,000 U / g.

[0040] In a preferred embodiment, the addition amount of the fermentation bacteria agent includes 0.1-3 parts (including but not limited to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2 or 3 parts) of yeast, 0.1-3 parts (including but not limited to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2 or 3 parts) of lactic acid bacteria and 0.1-3 parts (including but not limited to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2 or 3 parts) of spore bacteria; the addition amount of the complex enzyme agent is 0.1-3 parts (including but not limited to 0.1, 0.2, 0.3, 0.4, 0.5 , 0.6, 0.7, 0.8, 0.9, 1, 2 or 3 parts); the added amount of the fermentation carbon source includes 10-40 parts (including but not limited to 10, 15, 20, 25, 30, 35 or 40 parts) of corn flour, 10-35 parts (including but not limited to 10, 15, 20, 25, 30 or 35 parts) of DDGS, 10-25 parts of bran (including but not limited to 10, 15, 20 or 25 parts), 10-20 parts (including but not limited to 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 parts) of miscellaneous meal and 5-20 parts (including but not limited to 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 parts) of soybean meal.

[0041] The present application achieves enzyme-bacteria synergistic fermentation and balances the active ingredients such as live bacteria and flavor substances in the yeast culture by precisely controlling the addition amount of yeast additives, fermentation bacteria, fermentation carbon sources, fermentation nitrogen sources and compound enzyme agents. Although yeast additives contain ingredients that improve the rumen health of ruminants, excessive additions and types may inhibit the fermentation effect of bacteria agents, thereby affecting other nutrients in the yeast culture, limiting the growth of yeast, lactic acid bacteria and spore-forming bacteria, resulting in a low number of live bacteria after fermentation, and significantly reducing the content of bacterial metabolites such as lactic acid.

[0042] Therefore, although the types of yeast additives in the present application are rich, when they are controlled within the above range, they will not inhibit the overall fermentation effect of the bacterial agent, but can also cooperate with other ingredients to increase the active ingredients of the yeast in the yeast culture, so as to obtain a more comprehensive nutrition of the present application, and a yeast culture with the effects of multiple yeast-derived functional active ingredients, which can provide nutrition for ruminants while promoting the improvement of rumen health of ruminants and improving production performance.

[0043] The present application controls the addition amount of the fermentation carbon source and the fermentation nitrogen source within the above range to promote the fermentation effect of the fermentation bacteria and the complex enzyme agent, and ensure that the number of live bacteria in the yeast culture is maintained at an appropriate level. If the fermentation carbon source is too much, it may cause the bacterial enzyme to continue to ferment and produce excessive gas and acid, and then the packaging will be bloated after subsequent vacuum storage, affecting the storage and use of the yeast culture; but if the addition amount is too little, it will also lead to poor fermentation effect, reduced number of live bacteria, and ultimately reduced nutritional value of the yeast culture. Therefore, the present application balances the fermentation speed by precisely controlling the addition amount of the fermentation carbon source, yeast additives, fermentation bacteria and complex enzyme agent, so that the components work synergistically during the fermentation process and improve the overall fermentation effect to obtain the yeast culture of the present application.

[0044] In a preferred embodiment, the fermentation temperature is 25-35°C, including but not limited to 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C or 35°C.

[0045] In a preferred embodiment, the fermentation time is 3-5 days, including but not limited to 3, 4 or 5 days.

[0046] In a preferred embodiment, the fermentation system also contains water, and the mass of water accounts for 30-40% of the total mass of the fermentation system, including but not limited to 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39% or 40%.

[0047] The present application controls the fermentation temperature, time and moisture in the fermentation process so that the fermentation carbon source, fermentation bacteria agent and complex enzyme agent mentioned above in the present application can be fully mixed and fermented. The nutritional components of the yeast culture finally prepared can meet the level of the first-level concentrated feed of ruminant feed, and contain a large number of live bacteria and rich yeast-derived functional ingredients, which can meet the nutritional needs of ruminants, improve rumen health, promote feeding and digestion, enhance stress resistance and immunity, and improve the production performance of ruminants.

[0048] In a second typical embodiment of the present application, a yeast culture for ruminant feeding is provided, wherein the yeast culture is prepared by the above-mentioned method for preparing a yeast culture for ruminant feeding; based on dry matter mass, the contents of the components in the yeast culture include: crude protein ≥ 20wt%, acid-soluble protein mass in crude protein ≥ 30wt%, crude ash ≤ 10wt%, crude fiber ≤ 7wt%, lactic acid ≥ 2wt%, and mannan ≥ 2wt%; the number of live yeast cells ≥ 1×10 7 CFU / g, viable lactic acid bacteria count ≥ 1×10 8 CFU / g.

[0049] In a preferred embodiment, the yeast culture contains flavor substances; the flavor substances include one or more of alcohols, esters, acids, ketones, aldehydes or oxazines; preferably, the alcohol includes one or more of phenylethyl alcohol, isopentanol, n-hexanol, 2,3-butanediol or furfuryl alcohol; preferably, the ester includes one or more of ethyl hexanoate, 2-phenylethyl hexanoate, ethyl valerate, diethyl succinate, ethyl caprylate, ethyl laurate, ethyl nonanoate, ethyl butyrate, ethyl benzoate or ethyl palmitate; preferably, the ketone includes 3-hydroxy-2-butanone; preferably, the oxazines include one or more of 2,3-dimethyl-5-ethylpyrazine, ligustrazine, 2-ethyl-6-methylpyrazine or 2,3,5-trimethylpyrazine; preferably, the alcohol accounts for 30-35% of the total mass of the flavor substances, and the ester accounts for 40-45% of the total mass of the flavor substances; preferably, phenylethyl alcohol accounts for 20-25% of the total mass of the flavor substances.

[0050] The yeast culture of the present application contains a large amount of flavor substances, mainly fruity and floral flavor substances, among which the largest proportion of flavor substances are esters and alcohols, and the flavor substance with the highest content is phenylethanol. According to the records of TheGoodScentsCompany database, phenylethanol has the smell of flowers, dried roses, roses, and rose water. The yeast culture of the present application is mixed into the diet of ruminants instead of part of the refined supplement, which can improve the palatability of the diet feed, increase the animal's feed intake, and improve the feed conversion rate, so as to improve the production performance of ruminants.

[0051] In a preferred embodiment, after the yeast culture of the present application is subjected to an in vitro fermentation test (a technology that simulates specific digestion or metabolic processes in an organism under laboratory conditions, and the in vitro fermentation test device of the present application is an AGRS-III type microbial fermentation micro-gas production fully automatic recording device and software system), the total gas production in 72 hours is 320-400 mL / g, the methane concentration is 10.50±2.0ccCH4%, the methane production is 31.33±4.85 mL / g, the dry matter disappearance rate is 68.38±3.00%, and the pH is 6.67±0.01.

[0052] It is verified through the examples of the present application that when the yeast culture of the present application is compared with the commercially available refined supplements in the prior art, the total gas production (referring to the total amount of gas produced by the feed substrate in the in vitro gas production system under simulated animal rumen fermentation conditions, mainly including gases such as carbon dioxide, methane and hydrogen), dry matter digestibility and rumen fermentation liquid pH of the yeast culture of the present application are higher than those of the commercially available refined supplements, indicating that the utilization efficiency of different nutrients of the wet yeast culture of the present invention is higher, and at the same time, the bacterial activity is higher, which can regulate the activity of rumen microorganisms and increase the production of total volatile fatty acids and pH.

[0053] In the prior art, yeast culture is usually dried after fermentation for the convenience of circulation and preservation, which causes the loss of many beneficial biologically active substances and flavor substances during the drying process, reducing its own nutritional and functional properties. The present application obtains a wet yeast culture by a vacuum preservation method, retains a large number of live bacteria and yeast-derived functional ingredients, and has a high nutritional level.

[0054] In the examples of the present application, the above-mentioned yeast culture was applied to mutton sheep breeding. Compared with the prior art concentrated feed of the control group, the yeast culture of the present application showed obvious advantages in daily weight gain, dry matter intake and feed-to-weight ratio, indicating that the yeast culture of the present application has a significant promoting effect on the growth performance of mutton sheep, and can increase the total volatile fatty acid content in the rumen of mutton sheep and increase the rumen pH.

[0055] Moreover, when feeding lactating cows, the yeast culture of the present application significantly improves the feed intake and milk production of lactating cows compared to the above-mentioned concentrated feed. This is because the yeast culture of the present application is rich in fruit-flavored flavor enhancers and nutrients, which can improve the production performance of lactating cows and promote the economic benefits of ruminant breeding.

[0056] In a third typical embodiment of the present application, there is provided a yeast culture for ruminant feeding, and a yeast culture prepared by the method for preparing the yeast culture for ruminant feeding, and their use in ruminant feeding.

[0057] In a preferred embodiment, the application includes: mixing yeast culture, ruminant concentrate and ruminant roughage to obtain a ruminant diet, and feeding the ruminant; the addition amount of the yeast culture accounts for 5-20% of the total weight of the ruminant diet.

[0058] The nutritional level of most yeast cultures in the prior art is difficult to meet the requirements of fine supplements, and they are usually used as additives in ruminant feeds and mixed in the diet of ruminants. However, the nutritional level of the yeast culture of the present application can reach the nutritional level of fine supplements for ruminants, and can replace part of the fine supplements and be mixed in the basic diet to provide ruminants with more comprehensive nutrition, and can also integrate the functional active ingredients of yeast sources, promote spleen and stomach improvement, rumen health, enhance anti-stress ability and immunity, promote feeding and digestion, and improve the production performance of ruminants.

[0059] The beneficial effects of the present application will be further explained in detail below in conjunction with specific embodiments.

[0060] The reagents in the examples of this application are all conventional commercially available products unless otherwise specified. The yeast hydrolysate, yeast metabolites and yeast cell walls of this application are all from Angel Yeast Co., Ltd.

[0061] The specifications / characteristics of the reagents in the examples of this application and the information of the manufacturers are shown in Table 1.

[0062] Table 1

[0063]

[0064]

[0065] Example 1

[0066] (1) Seed solution preparation:

[0067] Weigh 0.1 parts of Saccharomyces cerevisiae powder and 3 parts of water by mass, stir at 30±5°C for 10 minutes to obtain yeast seed liquid.

[0068] According to the mass percentage, 0.1 parts of Lactobacillus plantarum powder and 3 parts of water were weighed, the temperature was 30±5°C, and the mixture was stirred for 10 minutes to obtain lactic acid bacteria seed liquid.

[0069] According to the mass percentage, 0.1 part of protease, 0.1 part of cellulase, 0.05 part of glucanase, 0.05 part of xylanase, 0.05 part of saccharifying enzyme, 0.05 part of α-amylase and 10 parts of water were weighed, the temperature was 30±5°C, and the stirring was carried out for 10 minutes to obtain the seed solution of the complex enzyme preparation.

[0070] (2) Inoculation and mixing: 27 parts of corn flour, 21 parts of DDGS, 20 parts of bran, 11 parts of rice bran meal, 10 parts of soybean meal, 1 part of yeast hydrolyzate, 8 parts of yeast metabolite dry powder, 2 parts of yeast cell wall, and the yeast seed liquid, lactic acid bacteria seed liquid, and complex enzyme preparation seed liquid in step (1) are fully mixed, and the moisture content is controlled at 36%.

[0071] (3) Fermentation: The mixed material in step (2) is transferred into a fermentation bag with a breathing buckle, sealed, and fermented at 30° C. for 3 days to terminate the fermentation.

[0072] (4) Vacuum packaging: After the fermentation in step (3) is completed, the material is vacuum-packed and stored in a vacuum packaging machine.

[0073] Example 2

[0074] (1) Seed solution preparation:

[0075] Weigh 0.1 parts of Saccharomyces cerevisiae powder and 3 parts of water by mass, stir at 30±5°C for 10 minutes to obtain yeast seed liquid.

[0076] According to the mass percentage, 0.1 part of Lactobacillus plantarum powder, 0.1 part of Lactobacillus buchneri powder, and 3 parts of water were weighed, and the temperature was 30±5° C. and stirred for 10 minutes to obtain lactic acid bacteria seed liquid.

[0077] According to the mass percentage, 0.1 parts of protease, 0.1 parts of cellulase, 0.05 parts of glucanase, 0.05 parts of xylanase and 10 parts of water were weighed, and the temperature was 30±5°C, and stirred for 10 minutes to obtain the seed solution of the complex enzyme preparation.

[0078] (2) Inoculation and mixing: 27 parts of corn flour, 21 parts of DDGS, 20 parts of bran, 11 parts of rice bran meal, 10 parts of soybean meal, 1 part of yeast hydrolyzate, 8 parts of yeast metabolite dry powder, 2 parts of yeast cell wall, and the yeast seed liquid, lactic acid bacteria seed liquid, and complex enzyme preparation seed liquid in step (1) are fully mixed in a mixer, and the moisture content is controlled to be about 36%.

[0079] (3) Fermentation: The mixed material in step (2) is transferred into a fermentation bag with a breathing buckle, sealed, and fermented at 30° C. for 3 days to terminate the fermentation.

[0080] (4) Vacuum packaging: After the fermentation in step (3) is completed, the material is vacuum-packed and stored in a vacuum packaging machine.

[0081] Example 3

[0082] (1) Seed solution preparation:

[0083] According to the mass ratio, 0.1 parts of Candida utilis powder and 3 parts of water were weighed, and the temperature was 30±5° C. and stirred for 10 minutes to obtain yeast seed liquid.

[0084] According to the mass percentage, 0.1 parts of Lactobacillus plantarum powder and 3 parts of water were weighed, the temperature was 30±5°C, and the mixture was stirred for 10 minutes to obtain lactic acid bacteria seed liquid.

[0085] According to the mass percentage, 0.1 part of protease, 0.1 part of cellulase and 10 parts of water were weighed, and the temperature was 30±5°C, and stirred for 10 minutes to obtain the seed solution of the complex enzyme preparation.

[0086] (2) Inoculation and mixing: 27 parts of corn flour, 21 parts of DDGS, 20 parts of bran, 11 parts of rice bran meal, 10 parts of soybean meal, 1 part of yeast hydrolyzate, 8 parts of yeast metabolite dry powder, 2 parts of yeast cell wall, and the yeast seed liquid, lactic acid bacteria seed liquid, and complex enzyme preparation seed liquid in step (1) are fully mixed in a mixer, and the moisture content is controlled to be about 36%.

[0087] (3) Fermentation: The mixed material in step (2) is transferred into a fermentation bag with a breathing buckle, sealed, and fermented at 30° C. for 3 days to terminate the fermentation.

[0088] (4) Vacuum packaging: After the fermentation in step (3) is completed, the material is vacuum-packed and stored in a vacuum packaging machine.

[0089] Example 4

[0090] (1) Seed solution preparation:

[0091] According to the mass percentage, 0.1 parts of Kluyveromyces marxii powder and 3 parts of water were weighed, the temperature was 30±5°C, and the mixture was stirred for 10 minutes to obtain yeast seed liquid.

[0092] According to the mass percentage, 0.1 parts of Lactobacillus casei powder and 3 parts of water were weighed, the temperature was 30±5°C, and stirred for 10 minutes to obtain lactic acid bacteria seed liquid.

[0093] According to the mass percentage, 0.2 parts of protease, 0.2 parts of cellulase, 0.05 parts of glucanase, 0.05 parts of xylanase, 0.05 parts of saccharifying enzyme, 0.05 parts of α-amylase and 10 parts of water were weighed, the temperature was 30±5°C, and stirred for 10 minutes to obtain the seed solution of the complex enzyme preparation.

[0094] (2) Inoculation and mixing: 27 parts of corn flour, 21 parts of DDGS, 20 parts of bran, 11 parts of rice bran meal, 10 parts of soybean meal, 1 part of yeast hydrolyzate, 8 parts of yeast metabolite dry powder, 2 parts of yeast cell wall, and the yeast seed liquid, lactic acid bacteria seed liquid, and complex enzyme preparation seed liquid in step (1) are fully mixed in a mixer, and the moisture content is controlled to be about 36%.

[0095] (3) Fermentation: The mixed material in step (2) is transferred into a fermentation bag with a breathing buckle, sealed, and fermented at 30° C. for 3 days to terminate the fermentation.

[0096] (4) Vacuum packaging: After the fermentation in step (3) is completed, the material is vacuum-packed and stored in a vacuum packaging machine.

[0097] Example 5

[0098] (1) Seed solution preparation:

[0099] Weigh 0.1 parts of saccharomyces cerevisiae powder and 3 parts of water by mass, stir at 30±5°C for 10 minutes to obtain yeast seed liquid.

[0100] According to the mass ratio, 0.1 part of Lactobacillus paracasei, 0.1 part of Lactobacillus acidophilus, and 3 parts of water were weighed, and the temperature was 30±5° C. and stirred for 10 minutes to obtain a lactic acid bacteria seed liquid.

[0101] According to the mass percentage, 0.1 part of Bacillus subtilis powder, 0.1 part of Bacillus licheniformis, and 3 parts of water were weighed, the temperature was 30±5°C, and stirred for 10 minutes to obtain Bacillus subtilis seed liquid.

[0102] According to the mass percentage, 0.2 parts of protease, 0.2 parts of cellulase, 0.05 parts of glucanase, 0.05 parts of xylanase, 0.05 parts of saccharifying enzyme, 0.05 parts of α-amylase and 10 parts of water were weighed, the temperature was 30±5°C, and stirred for 10 minutes.

[0103] (2) Inoculation and mixing: 27 parts of corn flour, 21 parts of DDGS, 20 parts of bran, 11 parts of rice bran meal, 10 parts of soybean meal, 1 part of yeast hydrolyzate, 8 parts of yeast metabolite dry powder, 2 parts of yeast cell wall, and the yeast seed liquid, lactic acid bacteria seed liquid, Bacillus seed liquid, and complex enzyme preparation seed liquid in step (1) are fully mixed in a mixer, and the moisture content is controlled to be about 36%.

[0104] (3) Fermentation: The mixed material in step (2) is transferred into a fermentation bag with a breathing buckle, sealed, and fermented at 30° C. for 3 days to terminate the fermentation.

[0105] (4) Vacuum packaging: After the fermentation in step (3) is completed, the material is vacuum-packed and stored in a vacuum packaging machine.

[0106] Example 6

[0107] The present application is different from Example 1 only in that corn flour is 10 parts, DDGS is 35 parts, bran is 19 parts, rice bran meal is 10 parts, palm meal is 10 parts, soybean meal is 5 parts, yeast hydrolyzate is 5 parts, yeast metabolite dry powder is 1 part, and yeast cell wall is 5 parts.

[0108] Example 7

[0109] The difference between the present application and Example 1 is that the present application contains 40 parts of corn flour, 10 parts of DDGS, 10 parts of bran, 18 parts of peanut meal, 10 parts of soybean meal, 1 part of yeast hydrolyzate, 10 parts of yeast metabolite dry powder, and 1 part of yeast cell wall.

[0110] Example 8

[0111] The only difference between the present application and Example 1 is that the fermentation raw materials and yeast additives and their added amounts are: 20 parts of corn flour, 15 parts of DDGS, 25 parts of bran, 10 parts of corn germ meal, 20 parts of soybean meal, 2 parts of yeast hydrolyzate, 5 parts of yeast metabolite dry powder, and 3 parts of yeast cell wall.

[0112] Example 9

[0113] The only difference between the present application and Example 1 is that the fermentation raw materials and yeast additives and their added amounts are: 5 parts of corn flour, 40 parts of DDGS, 20 parts of bran, 15 parts of rice bran meal, 3 parts of soybean meal, 2 parts of yeast hydrolyzate, 10 parts of yeast metabolite dry powder, and 5 parts of yeast cell wall.

[0114] Comparative Example 1

[0115] The only difference between the present application and Example 1 is that the fermentation raw materials and yeast additives and their added amounts are: 20 parts of corn flour, 35 parts of DDGS, 15 parts of bran, 10 parts of corn germ meal, 5 parts of soybean meal, 1 part of yeast hydrolyzate, 11 parts of yeast metabolite dry powder, and 3 parts of yeast cell wall.

[0116] Comparative Example 2

[0117] The present application is different from Example 1 only in that the fermentation raw materials and yeast additives and their added amounts are: 27 parts of corn flour, 24 parts of DDGS, 20 parts of bran, 11 parts of rice bran meal, 10 parts of soybean meal, 8 parts of yeast metabolite dry powder, and no yeast hydrolyzate and yeast cell wall.

[0118] Comparative Example 3

[0119] The present application is different from Example 1 only in that the fermentation raw materials and yeast additives and their added amounts are: 27 parts of corn flour, 21 parts of DDGS, 20 parts of bran, 11 parts of rice bran meal, 10 parts of soybean meal, 8 parts of yeast metabolite dry powder, and 3 parts of yeast cell wall hydrolyzate without yeast.

[0120] Test Example 1

[0121] The components of the fermentation original sample (the raw materials in Example 1 were mixed but not fermented) and the yeast culture prepared in Examples 1 to 9 were tested for the following indicators (GB / T 6432-2018 crude protein, NY / T 3801-2020 acid-soluble protein, GB / T 6438-2007 crude ash, GB / T 6434-2022 crude fiber, GB / T 20806-2022 neutral detergent fiber, GB / T20194-2018 starch, GB / T 23877-2009 lactic acid, NY / T 3477-2019 mannan and β-glucan) and microbial indicators (DB44 / T 1136-2013 lactic acid bacteria, GB 7300.501-2021 yeast, GB / T 26428-2010 bacillus). The results are shown in Tables 2 and 3.

[0122] Table 2

[0123]

[0124] Table 3

[0125] index Example 7 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Comparative Example 3 Crude Protein 21.0 22.5 21.1 19.9 19.4 18.8 Acid soluble protein: crude protein 32.6 32.3 30.7 31.2 30.8 30.2 Coarse ash 7.6 5.7 7.2 7.9 7.3 7.1 Crude Fiber 4.8 7.1 7.6 7.4 6.7 6.5 Neutral detergent fiber 29.6 30.7 35.9 34.3 32.6 31.4 starch 44.7 41.0 32.6 39.7 40.3 40.5 lactic acid 2.76 2.41 1.56 1.46 2.33 2.42 Mannan 5.9 6.9 7.6 7.2 5.3 7.2 β-Glucan 10.6 13.4 15.7 14.6 10.9 13.6 Lactic acid bacteria <![CDATA[2.6×10 8 ]]> <![CDATA[2.1×10 8 ]]> <![CDATA[1.4×10 7 ]]> <![CDATA[3.2×10 5 ]]> <![CDATA[2.1×10 8 ]]> <![CDATA[1.9×10 8 ]]> Yeast <![CDATA[1.2×10 7 ]]> <![CDATA[1.1×10 7 ]]> <![CDATA[1.1×10 7 ]]> <![CDATA[2.6×10 5 ]]> <![CDATA[1.2×10 7 ]]> <![CDATA[0.9×10 7 ]]> Bacillus <![CDATA[<10 5 ]]> <![CDATA[<10 5 ]]> <![CDATA[<10 5 ]]> <![CDATA[<10 5 ]]> <![CDATA[<10 5 ]]> <![CDATA[<10 5 ]]>

[0126] In Table 2 and Table 3, the unit of lactic acid bacteria, yeast and bacillus is "CFU / g", the unit of acid-soluble protein / crude protein is "%", and the other indicators are converted to the test values ​​under absolute dry conditions (the unit is "%").

[0127] As shown in Tables 2 and 3, the yeast culture for ruminants prepared by deep fermentation with the bacterial enzyme fermentation agent of the present invention can meet the requirements of crude protein ≥ 20%, acid-soluble protein: crude protein ≥ 30%, crude ash ≤ 10%, crude fiber ≤ 7%, lactic acid ≥ 2%, mannan ≥ 2%, yeast ≥ 1×10 7 CFU / g, lactic acid bacteria ≥1×10 8 CFU / g, lactic acid, mannan, acid-soluble protein, lactic acid bacteria and yeast content were all high. When the addition of corn flour was less than 10 parts and the addition of yeast metabolites was greater than 10 parts, the number of lactic acid bacteria and yeast live bacteria decreased significantly, and the lactic acid content decreased significantly.

[0128] Test Example 2

[0129] The yeast culture prepared in Example 1 was selected and its flavor components were determined by GC-MS. Headspace solid phase microextraction: 5 g of yeast culture sample was weighed and evenly loaded into a 20 mL headspace sample bottle, and the sample could not exceed 1 / 2 of the headspace sample bottle. The sample was incubated for 10 min, with a shaking speed of 450 r / min, an incubation temperature of 60°C, an extraction depth of 22 mm, an extraction time of 20 min, an injection depth of 42 mm, a desorption time of 180 s, and an aging of the solid phase microextraction head at 250°C for 5 min, and automatic injection.

[0130] GC conditions: chromatographic column: TG-5SILMS (30m×0.25mm×0.25μm), carrier gas: BIP He, carrier gas flow rate: 1.2mL / min. Column temperature: initial temperature 60℃, retention 2min, increase to 200℃ at 10℃ / min, retention 0min, increase to 300℃ at 20℃ / min, retention 3min; injection hole temperature 250℃, split flow rate: 50mL / min, split ratio: 33.3.

[0131] MS conditions: ionization mode EI; electron energy 70 eV; ion source temperature 250°C; detection mode: full scan, the entire mass scan range is 40-500 m / z, and the time is 24 min.

[0132] Qualitative and quantitative analysis: After GC-MS analysis, the retention index of the detected substance is calculated based on the retention time of normal alkanes. The mass spectrum of full ion scanning is compared with the standard spectrum in the NIST database (National Institute of Standards and Technology) to identify the substance.

[0133] The Chinese substances matching the CAS number were searched through the ChemicalBook website, and then the flavor descriptions of the corresponding substances were searched using the Good Scents Company database. The results are shown in Table 4 (the top 20 flavor substances in terms of content).

[0134] Table 4

[0135]

[0136] The flavor substances are mainly alcohols, esters, acids, ketones, aldehydes and azine substances. The largest flavor substances in the yeast culture are esters (42.37%) and alcohols (34.65%). Among them, the flavor substance with the highest content is phenylethanol, accounting for about 21.89%. The schematic diagram of the flavor substance composition of the yeast culture is shown in the figure below: Figure 1 As shown in Table 4 and Figure 1 It can be seen that the flavor substances of the yeast culture of the present application are mainly fruity, floral and other flavor substances.

[0137] Test Example 3

[0138] The yeast culture samples prepared in Example 1 and the commercially available mutton concentrate supplement (British United Aibon-Growth and Fatten Sheep Concentrate Supplement 7117) were tested for conventional nutritional indicators (GB / T 6435-2014 moisture, GB / T 6432-2018 crude protein, GB / T 6438-2007 crude ash, GB / T 6433-2006 crude fat, GB / T 6434-2022 crude fiber, GB / T 6436-2018 calcium, GB / T 6437-2018 total phosphorus, GB / T 20194-2018 starch, GB / T 18246-2019 amino acids) and microbial indicators (DB44 / T 1136-2013 lactic acid bacteria, GB 7300.501-2021 yeast) with reference to national standards and industry standards. The results are shown in Tables 5 and 6. Figure 2 shown.

[0139] Table 5

[0140] Dry matter Crude Protein Crude fat Crude Fiber Coarse ash calcium phosphorus starch Lactic acid bacteria Yeast Example 1 94.60 22.2 6.1 6.5 7.2 0.14 1.18 40.7 <![CDATA[≥1×10 8 ]]> <![CDATA[≥1×10 7 ]]> Sheep supplement 89.00 18.5 2.5 6.8 6.9 1.02 0.58 44.5 <![CDATA[<10 5 ]]> <![CDATA[<10 5 ]]>

[0141] In Table 5, the units of lactic acid bacteria and yeast are "CFU / g", and the other indicators are all converted to absolute dry condition test values ​​(the unit is "%).

[0142] From Table 2, Table 3, Table 5 and Figure 2 It can be seen that the conventional nutritional indicators (crude protein, crude fat, crude fiber and amino acid composition) of the yeast culture of the present application are slightly higher than those of the refined supplementary feed for mutton, and it is rich in active ingredients such as lactic acid, acid-soluble protein ratio, mannan and tens of millions of live bacteria, and its overall nutritional value is higher than that of the refined supplementary feed.

[0143] Test Example 4

[0144] The yeast culture in Example 1 and the above-mentioned refined supplement were subjected to ruminant in vitro bionic digestion evaluation, and the specific steps were as follows:

[0145] Before morning feeding, rumen fluid from 10 healthy Hu sheep of similar age and weight was collected using a rumen fluid collector. After filtering through 4 layers of gauze, equal volumes were mixed and prepared into artificial rumen culture fluid with buffer solution (pH = 6.85) at a ratio of 1:2.

[0146] The in vitro fermentation device uses the "AGRS-III type microbial fermentation micro-gas production fully automatic recording device and software system". Six replicate groups are set for each sample. 1.000g of sample (yeast culture and commercially available fine supplement) is weighed in each replicate group and placed in a 140mL anaerobic fermentation bottle. 75mL of artificial rumen culture medium is added to each fermentation bottle. Carbon dioxide is introduced into the fermentation bottle for 3 to 5 seconds to exclude air, and the chitin plug is immediately covered and the Heinz screw cap is tightened. The fermentation bottles are connected one by one to the corresponding gas channels of the gas production device, and the samples are collected after continuous culture at 39°C for 72 hours.

[0147] The in vitro fermentation characteristics of the yeast culture of Example 1 compared with the refined feed ruminant are shown in Table 6.

[0148] Table 6

[0149]

[0150]

[0151] Note: In Table 6, data with different shoulder letters in the same row have significant differences (P < 0.05), and data with the same shoulder letters or no letter have no significant differences (P > 0.05).

[0152] As shown in Table 6, the total gas production of the yeast culture of Example 1 is significantly higher than that of the control group's supplemented feed, which is 20% higher than that of the supplemented feed; the dry matter disappearance rate of Example 1 is significantly higher than that of the supplemented feed, which is 10% higher than that of the supplemented feed digestibility; the pH of Example 1 is higher than that of the supplemented feed group, which is 0.14 higher than that of the supplemented feed group; the methane concentration and output of the Example 1 group are lower than those of the supplemented feed group. In summary, the total gas production of the yeast culture of the present application is higher, the pH is higher, and the dry matter disappearance rate is greater, indicating that the nutritional value of the yeast culture itself is higher than that of the supplemented feed, and it can stabilize the pH of the rumen fluid, reduce methane production, and thus reduce environmental pollution and energy loss.

[0153] Test Example 5

[0154] The effect of the yeast culture of Example 1 of the present application on the growth performance and rumen health of mutton sheep was detected by the following detection method:

[0155] 1. Study on the effect of yeast culture on the growth performance of mutton sheep

[0156] This test adopted a single-factor randomized block design. A total of 96 healthy Hu sheep with an age of 27.3±3 kg and a body weight were selected and randomly divided into 4 groups, with 6 replicates in each group and 4 Hu sheep in each replicate. The sheep were raised in separate pens and fed twice a day with free access to food and water. The specific design is shown in Table 7.

[0157] The basic diet is prepared in accordance with the "Fattening Sheep Feeding Standard" in the "Meat Sheep Feeding Standard" (NY / T816-2004), and the basic diet group is "fine supplement feed + peanut seedlings (roughage)". Among them, the fine supplement feed uses "British United Aiborn-Growing and Fattening Sheep Fine Supplement Feed 7117", and its product ingredients are guaranteed as follows: moisture ≤ 13.0%, crude protein ≥ 17.0%, crude ash ≤ 12.0%, crude fiber ≤ 13.0%, lysine ≥ 0.50%, sodium chloride 1.0% ~ 2.5%, total phosphorus ≥ 0.45%, calcium 1.0% ~ 2.0%.

[0158] During the transition period, the concentrate-to-roughage ratio was gradually adjusted from 5:5 to 7:3 (70% concentrate and 30% peanut seedlings), with a pre-trial period of 10 days and a trial period of 90 days. During the trial, all feeding management was carried out in accordance with the basic feeding management of the ranch. The effects of dry / wet yeast culture replacing different proportions of concentrate supplements on the production performance of mutton sheep are shown in Table 8.

[0159] Table 7

[0160] Trial Groups deal with Sample size Control group Basic diet 6×4 10％ Yeast culture replaces 10% of the concentrate feed 6×4 20％ Yeast culture replaces 20% of the concentrate feed 6×4 40％ Yeast culture replaces 40% of the concentrate feed 6×4

[0161] Table 8

[0162]

[0163] In Table 8, dry basis feed intake refers to dry matter feed intake converted to absolute dry state; wet basis feed intake refers to feed intake under current moisture conditions of feed.

[0164] From the results in Table 8, it can be seen that the feed intake and daily weight gain of the test group are higher than those of the control group, and the feed-to-meat ratio is lower than that of the control group; the daily weight gain of the group replacing 10% of the fine supplement is the highest, which is 16.23% higher than that of the control group, and the feed-to-meat ratio is the lowest, which is 0.62 lower than that of the control group, and the dry matter intake is 6.4% higher than that of the control group. Overall, as the wet yeast culture of the present invention replaces the fine supplement ratio of 10%-40%, its daily weight gain and feed intake are higher than the control group, and the feed-to-meat ratio is lower than that of the control group, indicating that feeding the yeast culture of the present application can improve the growth performance of mutton sheep and improve economic benefits. The most suitable addition ratio in the basic diet of ruminants is 5%-20% of the total weight of the diet.

[0165] 2. Effect of yeast culture replacing different proportions of concentrated feed on rumen fluid fermentation of mutton sheep

[0166] On the 90th day of the experiment, rumen fluid was collected before feeding in the morning. Rumen fluid from one sheep in each group and each pen was collected and immediately filtered with a sterile 4-layer gauze. The filtrate was divided into 10 mL centrifuge tubes for the determination of various indicators of rumen fluid. 10 mL of the divided rumen fluid was taken for pH determination immediately; another 10 mL of rumen fluid was taken and added with 0.1 mL of 6 mol / L hydrochloric acid for nitrogen fixation. Another 5 mL of rumen fluid was centrifuged (10000×g, 10 min), 1.5 mL of the supernatant after centrifugation was taken, and 0.15 mL of metaphosphoric acid (25%) was added, shaken, allowed to stand for 30 min, and centrifuged again (10000×g, 15 min), and the supernatant was taken for the determination of VFA content. All processed samples were frozen and stored in a -20°C refrigerator. The results of the effect of the yeast culture of the present application on the fermentation of rumen fluid of mutton sheep in different proportions of fine supplements are shown in Table 9.

[0167] Table 9

[0168]

[0169] Note: In Table 9, data with different shoulder letters in the same row indicate significant differences (P < 0.05), and data with the same shoulder letters or no letter indicate no significant differences (P > 0.05). In Table 9, TVFA refers to "Total Volatile Fatty Acids", which means total volatile fatty acids.

[0170] From the results in Table 9, it can be seen that the rumen fluid pH of the test groups (10%, 20%) is higher than that of the control group, among which the pH of the 10% group is significantly improved compared with the control group, and as the proportion of yeast culture replacing semen supplement increases, the pH shows a downward trend; the ammonia nitrogen content increases with the increase in the proportion of wet yeast culture replacing semen supplement, indicating that the dry basis crude protein content of yeast culture is higher than that of semen supplement; the total volatile fatty acid content (TVFA) of the test groups (10%, 20%) is higher than that of the control group, among which the 10% group is 6% higher than that of the control group. Overall, the pH, ammonia nitrogen and total volatile acid of the 10% and 20% groups are improved compared with the control group, but when the addition amount is increased to 40%, the pH decreases and TVFA also decreases, indicating that when the yeast culture of the present application replaces the semen supplement at a dosage of ≤20%, it can increase the rumen fermentation pH and total volatile acid, improve the feed utilization efficiency of mutton sheep and improve the rumen health.

[0171] Test Example 6

[0172] The effect of the yeast culture of the present application (Example 1) on the feeding and milk production of dairy cows was investigated as follows:

[0173] A single-factor randomized block design was used to select 200 Holstein cows with good body condition, average daily milk production (33.4±1.3Kg), parity (1.4±0.1) and similar lactation period (96.4±11.4 days), and randomly divided into 2 groups, 100 cows in each group. The control group was fed a basic diet for lactating cows with a concentrate-to-roughage ratio of 5:5, of which the concentrate feed was Cargill lactating dairy cow concentrate supplement 1812. The experimental group was: the yeast culture of Example 1 of the present application replaced 10% of the concentrate supplement and was mixed into the basic diet. The pre-test period was 10 days, and the main test period was 30 days. The results of the effect of yeast culture instead of concentrate supplement on the feed intake and milk production of dairy cows are shown in Table 10.

[0174] Table 10

[0175]

[0176] From the results in Table 10, it can be seen that when 10% yeast culture was used as a supplement for dairy cows, the dry matter intake was increased by 2.56% compared with the control group, the milk production was increased by 6.84% compared with the control group, and the feed conversion rate was increased by 0.06 compared with the control group. This shows that the use of yeast culture as a supplement for 10% dairy cows can increase milk production and improve economic benefits.

[0177] Test Example 7

[0178] The effect of the yeast culture of the present application (Example 1) on the feeding and weight gain of Simmental cattle was investigated as follows:

[0179] A single-factor randomized block design was used to select 90 Simmental beef cattle in good condition and healthy, with an average weight of about 380 kg, and randomly divided them into a control group and an experimental group, with 45 in each group. The control group was fed a basic diet for beef cattle, with a concentrate-roughage ratio of 7:3, of which the concentrate feed was Cargill's concentrate supplement for growing beef cattle 813300GT, and the experimental group replaced 10% of the concentrate supplement in the basic diet. The pre-trial period was 10 days and the main trial period was 90 days. The results of the effect of yeast culture on the production performance of Simmental beef cattle are shown in Table 11.

[0180] Table 11

[0181]

[0182] From the results in Table 11, it can be seen that when 10% yeast culture was used as a supplement for Simmental beef cattle, the dry matter intake was increased by 7.51% and the daily weight gain was increased by 10.88% compared with the control group, and the feed-to-meat ratio decreased by 0.22. This shows that replacing 10% of the beef cattle's supplement with yeast culture can increase feed intake and daily weight gain, and improve feed compensation.

[0183] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: the yeast culture of the present application can match the nutritional level of the first-level refined supplement for ruminant feed, and contains yeast-derived functional active ingredients such as yeast hydrolyzate, yeast metabolites, yeast cell walls and live yeast. Through bacterial enzyme synergistic fermentation and wet vacuum preservation, a large amount of live bacteria, enzyme activity, and yeast-derived active ingredients are retained in the yeast culture finally prepared. The nutritional value is balanced and rich, with a fruity flavor, and can be used to replace refined supplements in large proportions. When it is mixed into the daily diet of ruminants as refined supplements, it significantly improves the rumen health of ruminants, enhances stress resistance, promotes feeding and digestion, and improves the production performance of ruminants compared to commercially available refined supplements.

[0184] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a yeast culture for feeding ruminants, characterized in that: The preparation method comprises: The fermentation raw materials, yeast additives, fermentation bacteria and compound enzymes are mixed and fermented to obtain the yeast culture; The yeast additive includes yeast hydrolyzate, yeast metabolite or yeast cell wall; The fermentation bacteria include: one or more of yeast, lactic acid bacteria or spore bacteria; The yeast additive comprises 1-5 parts of the yeast hydrolysate, 1-10 parts of the yeast metabolites and 1-5 parts of the yeast cell walls; The fermentation raw materials include a fermentation carbon source and a fermentation nitrogen source; The fermentation carbon source includes corn flour and bran; The fermentation nitrogen sources include soybean meal, miscellaneous meal and DDGS.

2. The preparation method according to claim 1, characterized in that: The complex enzyme agent comprises: one or more of protease, cellulase, xylanase, glucanase, saccharifying enzyme or α-amylase; Preferably, the miscellaneous meal includes one or more of corn germ meal, rice bran meal, peanut meal, rapeseed meal, sunflower meal, palm meal, cottonseed meal, sesame meal or flax meal.

3. The preparation method according to claim 1, characterized in that: The yeast includes one or more of Saccharomyces cerevisiae, Candida utilis or Kluyveromyces marxianus; The lactic acid bacteria include one or more of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus buchneri, Lactobacillus paracasei, Lactobacillus acidophilus, Pediococcus acidilactici, Enterococcus faecalis or Enterococcus faecium; The spore-forming bacteria include one or more of Bacillus subtilis, Bacillus licheniformis, Bacillus coagulans or Brevibacillus laterosporus; Preferably, the yeast is yeast powder, the lactic acid bacteria is lactic acid bacteria powder, and the spore bacteria is spore bacteria powder; Preferably, the viable count of the yeast powder is 5-30 billion cfu / g; Preferably, the viable count of the lactic acid bacteria powder is 10-100 billion cfu / g; Preferably, the viable bacterial count of the Bacillus powder is 10-100 billion cfu / g.

4. The preparation method according to claim 1, characterized in that: The activity of the protease is 50,000-300,000 U / g, the activity of the cellulase is 5,000-100,000 U / g, the activity of the xylanase is 5,000-100,000 U / g, the activity of the glucanase is 5,000-100,000 U / g, the activity of the saccharifying enzyme is 5,000-200,000 U / g, and the activity of the α-amylase is 10,000-300,000 U / g.

5. The preparation method according to any one of claims 1 to 4, characterized in that: By mass fraction, The added amount of the fermentation agent includes one or more of 0.1-3 parts of the yeast, 0.1-3 parts of the lactic acid bacteria, or 0.1-3 parts of the spore bacteria; The added amount of the complex enzyme agent is 0.1-3 parts; The amount of fermentation raw materials added is 45 to 140 parts; The fermentation raw materials include 10-40 parts of corn flour, 10-35 parts of DDGS, 10-25 parts of bran, 10-20 parts of miscellaneous meal and 5-20 parts of soybean meal.

6. The preparation method according to claim 1, characterized in that: The fermentation temperature is 25-35°C; Preferably, the fermentation time is 3-5 days.

7. The preparation method according to claim 1, characterized in that: The fermentation system also contains water, and the mass of the water accounts for 30-40% of the total mass of the fermentation system.

8. A yeast culture for feeding ruminants, characterized in that: The yeast culture is prepared by the method for preparing a yeast culture for feeding ruminants according to any one of claims 1 to 7; Calculated by dry matter mass, the contents of the components in the yeast culture include: crude protein ≥ 20wt%, acid-soluble protein mass in the crude protein ≥ 30%, crude ash ≤ 10wt%, crude fiber ≤ 7wt%, lactic acid ≥ 2wt%, and mannan ≥ 2wt%; The number of live yeast cells in the yeast culture is ≥ 1×10 7 CFU / g, viable lactic acid bacteria count ≥ 1×10 8 CFU / g.

9. The yeast culture according to claim 8, characterized in that The yeast culture contains flavor substances; The flavor substances include one or more of alcohol, ester, acid, ketone, aldehyde or oxazine; Preferably, the alcohol comprises one or more of phenylethyl alcohol, isopentanol, n-hexanol, 2,3-butanediol or furfuryl alcohol; Preferably, the ester includes one or more of ethyl hexanoate, 2-phenylethyl hexanoate, ethyl valerate, diethyl succinate, ethyl caprylate, ethyl laurate, ethyl nonanoate, ethyl butyrate, ethyl benzoate or ethyl palmitate; Preferably, the ketone comprises 3-hydroxy-2-butanone; Preferably, the oxazine includes one or more of 2,3-dimethyl-5-ethylpyrazine, ligustrazine, 2-ethyl-6-methylpyrazine or 2,3,5-trimethylpyrazine.

10. The method for preparing a yeast culture for ruminant feeding according to any one of claims 1 to 7, or use of the yeast culture for ruminant feeding according to any one of claims 8 or 9 in ruminant feeding; Preferably, the application includes: The yeast culture, the concentrated supplementary feed for the ruminant and the roughage for the ruminant are mixed to obtain the ruminant diet, and the ruminant is fed; the addition amount of the yeast culture accounts for 5-20% of the total weight of the ruminant diet.

Images