Organic metal chelate for feed as well as preparation method and application of organic metal chelate

Abstract

The invention discloses an organic metal chelate for feed as well as a preparation method and application of the organic metal chelate. The organic metal chelate for the feed is obtained by mixing vegetable protein and a metal compound and then carrying out fermentation treatment, enzymolysis treatment and chelating treatment, the metal compound is selected from one or more of copper sulfate pentahydrate, ferrous sulfate heptahydrate, zinc sulfate heptahydrate and manganese sulfate monohydrate. The organic metal chelate for feed has both macromolecular and micromolecular organic metal chelate for feed, can significantly improve the production performance, heart index, chest muscle quality and body oxidation resistance of yellow feather broilers, improve body trace element deposition and intestinal immune function, and improve the immunity of yellow feather broilers. The concentration of iron and copper in serum and deposition of iron and copper elements in pectoralis and manganese elements in tibia are improved, and meanwhile, the discharge amount of iron, copper, zinc and manganese elements in excrement is remarkably reduced.

Description

Technical Field

[0001] The invention relates to the technical field of livestock product feed, and in particular to an organic metal chelate for feed and a preparation method and application thereof. Background Art

[0002] Trace elements in feed are mainly added in the form of inorganic trace elements. Inorganic trace elements are widely favored because of their low price, but there are many problems in the application of inorganic trace elements. For example, they are easy to combine with anti-nutritional factors such as phytic acid to form compounds that are difficult to digest and utilize, and the antagonism between different trace elements leads to reduced absorption efficiency and biological efficacy in the small intestine. In addition, inorganic trace elements have poor stability and are easily degraded, which can easily lead to the loss of trace elements. Therefore, they are often added in excess to meet the trace element requirements for normal growth of animals. The high-dose use of trace elements can cause environmental pollution, livestock product quality and safety problems. The Ministry of Agriculture and Rural Affairs has issued relevant announcements to regulate the safe use of trace elements in the breeding production process. Summary of the invention

[0003] The technical problem to be solved by the present invention is also to provide an organic metal chelate for feed, which can improve the production performance, cardiac index, breast muscle quality and antioxidant capacity of yellow-feathered broilers, improve the body's trace element deposition, intestinal immune function, and increase the concentration of iron and copper in serum and the deposition of iron and copper in the breast muscle and manganese in the tibia, while significantly reducing the discharge of iron, copper, zinc and manganese in feces.

[0004] The technical problem to be solved by the present invention is to provide a method for preparing an organic metal chelate for feed, thereby obtaining an organic metal chelate for feed having both macromolecules and small molecules, and simultaneously obtaining metal chelates of polypeptides, small peptides, free amino acids, monosaccharides and oligosaccharides and organic acids.

[0005] In order to solve the above problems, the present invention provides an organic metal chelate for feed, which is obtained by mixing plant protein with a metal compound and then subjecting it to fermentation, enzymatic hydrolysis and chelation treatment. The metal compound is selected from one or more of cupric sulfate pentahydrate, ferrous sulfate heptahydrate, zinc sulfate heptahydrate and manganese sulfate monohydrate.

[0006] In some embodiments, the organic metal chelate for feed includes iron, copper, zinc and manganese, wherein the mass of zinc: the mass of iron: the mass of copper: the mass of manganese is (45-75): (175-215): (3-10): (95-165).

[0007] In order to solve the above problems, the present invention provides a method for preparing an organic metal chelate for feed, comprising the following steps:

[0008] mixing peanut meal and a metal compound to obtain a peanut meal metal compound mixture;

[0009] adding water to the peanut meal metal compound mixture, and then inoculating Bacillus subtilis and lactic acid bacteria into the peanut meal metal compound mixture for solid-state fermentation to obtain a first product;

[0010] Add cellulase, xylanase, carboxypeptidase and aminopeptidase to the first product and perform enzymatic hydrolysis to obtain a second product;

[0011] The second product is kept warm at a preset temperature to obtain an organic metal chelate for feed;

[0012] The metal compound is selected from one or more of copper sulfate pentahydrate, ferrous sulfate heptahydrate, zinc sulfate heptahydrate and manganese sulfate monohydrate.

[0013] In some embodiments, the amount of cellulase added is 700U / g to 1500U / g;

[0014] The added amount of the xylanase is 700U / g to 1500U / g;

[0015] The added amount of the carboxypeptidase is 1000U / g to 1500U / g;

[0016] The added amount of the aminopeptidase is 1500U / g to 2000U / g.

[0017] In some embodiments, the enzymatic hydrolysis treatment is carried out at a temperature of 37° C. to 40° C. and for a time of 4 to 5 hours.

[0018] In some embodiments, the sum of the inoculation amounts of Bacillus subtilis and the lactic acid bacteria is 8 wt% to 11 wt%;

[0019] The mass ratio of the Bacillus subtilis to the lactic acid bacteria is 1:(2-3).

[0020] In some embodiments, the mass ratio of the peanut meal to the metal compound is 1000:(15-25).

[0021] In some embodiments, the material-water ratio of the peanut meal metal compound mixture to water is 1: (0.6-0.9) g / mL.

[0022] In some embodiments, the fermentation temperature of the solid-state fermentation is 31°C to 35°C;

[0023] The fermentation time of the solid-state fermentation is 48h to 52h.

[0024] In some embodiments, the second product is kept at 55° C. to 60° C. for 60 min to 120 min.

[0025] The present invention also provides an application of an organic metal chelate for feed, wherein the organic metal chelate for feed is applied to feed for yellow-feathered broilers.

[0026] The implementation of the present invention has the following beneficial effects:

[0027] The organic metal chelate for feed provided by the present invention is formed by mixing plant protein with a metal compound, followed by fermentation, enzymolysis and chelation, wherein the metal compound is selected from one or more of copper sulfate pentahydrate, ferrous sulfate heptahydrate, zinc sulfate heptahydrate and manganese sulfate monohydrate. In its preparation method, peanut meal is first mixed with the metal compound, and the fermentation process is controlled so that the peanut meal produces more polypeptides and a small part of small peptides and free amino acids during the fermentation process, the polypeptides are combined with the metal compound to form a macromolecular organic metal chelate for feed, and the small peptides and free amino acids are combined with the metal compound to form a small molecular organic metal chelate for feed. Next, the fermentation product of the peanut meal is further degraded by controlling the enzymolysis process to obtain more free amino acids, monosaccharides or oligosaccharides and organic acids, and the above substances are combined with the metal compound to form a small molecular organic metal chelate for feed, and finally the organic metal chelate for composite feed is obtained. The above-mentioned feed uses organic metal chelates to replace high doses or equivalent added amounts of inorganic trace elements, which can significantly improve the production performance, cardiac index, breast muscle quality and antioxidant capacity of yellow-feathered broilers, improve the body's trace element deposition, intestinal immune function, and increase the concentration of iron and copper in serum and the deposition of iron and copper in the breast muscle and manganese in the tibia, while significantly reducing the discharge of iron, copper, zinc and manganese in feces. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The effect of an organic metal chelate for feed provided by the present invention on the growth performance of yellow-feathered broilers;

[0029] Figure 2 The invention provides an organic metal chelate for feed, which has an effect on the carcass traits of yellow-feathered broiler chickens.

[0030] Figure 3 The effect of an organic metal chelate for feed provided by the present invention on organ indexes of yellow-feathered broiler chickens;

[0031] Figure 4 The effect of an organic metal chelate for feed provided by the present invention on the quality of yellow-feathered broiler meat;

[0032] Figure 5 The effect of an organic metal chelate for feed provided by the present invention on the antioxidant capacity of yellow-feathered broilers;

[0033] Figure 6 The invention discloses an organic metal chelate for feed, which is provided by the present invention, and shows an effect on the deposition of trace elements in the body of yellow-feathered broilers.

[0034] Figure 7 The effect of an organic metal chelate for feed provided by the present invention on the excrement discharge of yellow-feathered broiler chickens;

[0035] Figure 8 The invention provides an organic metal chelate for feed, which has an effect on the intestinal morphology of yellow-feathered broilers;

[0036] Fig. 9 The present invention provides an organic metal chelate for feed, which affects the mRNA expression of tight junction proteins and inflammatory factors in the jejunal mucosa of yellow-feathered broilers. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0038] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0042] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0043] In the present invention, "preferred" and "better" are only used to describe implementation methods or embodiments with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of the present invention. In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features. In the present invention, when involving numerical ranges, unless otherwise specified, the two endpoints of the numerical range are included.

[0044] In order to solve the above problems, the present invention provides an organic metal chelate for feed, which is obtained by mixing plant protein with a metal compound and then subjecting it to fermentation, enzymolysis and chelation treatment. The metal compound is selected from one or more of cupric sulfate pentahydrate, ferrous sulfate heptahydrate, zinc sulfate heptahydrate and manganese sulfate monohydrate.

[0045] In some embodiments, the organic metal chelate for feed includes iron, copper, zinc and manganese, wherein the mass of zinc: the mass of iron: the mass of copper: the mass of manganese is (45-75): (175-215): (3-10): (95-165). Trace elements iron, copper, manganese and zinc are essential trace elements in animals and can be used as cofactors or activators of enzymes. Adding the above four metal elements at the same time according to the above ratio is beneficial to promoting the growth and development of chickens, enhancing immunity and improving meat quality.

[0046] Accordingly, the present invention provides a method for preparing an organic metal chelate for feed, comprising the following steps:

[0047] S1, mixing peanut meal and a metal compound to obtain a peanut meal metal compound mixture;

[0048] In some embodiments, the peanut meal is sterilized in an environment of 100° C. to 110° C. for 10 to 15 minutes before being mixed with the metal compound, so as to kill harmful microorganisms and improve the safety and stability of the fermentation process.

[0049] In some embodiments, the metal compound is selected from one or more of copper sulfate pentahydrate, ferrous sulfate heptahydrate, zinc sulfate heptahydrate and manganese sulfate monohydrate; trace elements iron, copper, manganese and zinc are essential trace elements in animals and can serve as cofactors or activators of enzymes. Adding the above four metal compounds at the same time is beneficial to promoting the growth and development of yellow-feathered broilers, enhancing immunity and improving meat quality.

[0050] In some embodiments, the mass ratio of the peanut meal to the metal compound is 1000:(15-25). Preferably, the mass ratio of the peanut meal to the metal compound is 1000:(10-13). It should be noted that increasing the amount of peanut meal added is beneficial to improving the chelation rate, but too much peanut meal will cause the chelation sites of the polypeptide produced after fermentation to be saturated with the metal, and the chelation reaction may stop, resulting in a waste of raw materials.

[0051] S2, adding water to the peanut meal metal compound mixture, and then inoculating Bacillus subtilis and lactic acid bacteria into the peanut meal metal compound mixture for solid-state fermentation to obtain a first product;

[0052] Water has a crucial influence on solid-state fermentation. The water content affects the dissolution of nutrients and the air permeability of the culture medium, thereby affecting the growth of the strain. In some embodiments, the material-water ratio of the peanut meal metal compound mixture to water is 1: (0.6-0.9) g / mL.

[0053] In some embodiments, the sum of the inoculation amounts of Bacillus subtilis and the lactic acid bacteria is 8wt% to 11wt%; too little inoculation will result in a lower content of active substances after fermentation, but too much inoculation will limit the growth of the bacteria and may decompose the obtained bioactive substances, ultimately reducing the chelation rate of metal compounds. In addition, during the solid-state fermentation process, the fermentation temperature and fermentation time also have a certain effect on the fermentation process. In some embodiments, the fermentation temperature of the solid-state fermentation is 31°C to 35°C; the fermentation time of the solid-state fermentation is 48h to 52h.

[0054] The present invention adopts Bacillus subtilis and lactic acid bacteria for synergistic fermentation. Among them, Bacillus subtilis can increase the polypeptide content in the fermentation product of peanut meal, and the metal chelate of peanut meal polypeptide has high stability. As a chicken feed additive, it can regulate the immunity of chicken body, strengthen the regulation of physiological laws, promote growth and development, and improve the quality of livestock products. Moreover, the metal chelate of peanut meal polypeptide can enhance the antioxidant capacity of chicken body, improve the lipid metabolism and intestinal health of chicken body. Lactic acid bacteria fermentation of peanut meal is more conducive to the production of antioxidant peptides and organic acids, among which antioxidant peptide metal chelates are conducive to reducing free radicals in chicken body, improving body immunity, and making meat more firm, delicious, green and healthy. In some embodiments, the mass ratio of the Bacillus subtilis and the lactic acid bacteria is 1: (2-3). Under this condition, not only the yield of polypeptides in the fermentation process can be increased, but also the yield of antioxidant polypeptide metal compound chelates can be at a higher level.

[0055] S3, adding cellulase, xylanase, carboxypeptidase and aminopeptidase to the first product and performing enzymatic hydrolysis to obtain a second product;

[0056] The present invention is based on fermentation, and a specific enzyme is used for enzymolysis reaction, and macromolecular proteins are further degraded, thereby increasing the content and type of the organic metal chelate for feed obtained in the end. Among them, the addition of cellulase and xylanase can increase the content of monosaccharides and oligosaccharides in the second product, and the monosaccharide and oligosaccharide metal chelates can promote the synthesis of growth-related hormones in chickens, promote intestinal microecological balance, protect intestinal mucosa, and improve the body's immune function. Carboxypeptidase and aminopeptidase are terminal peptidases, which hydrolyze peptide chains into amino acids and shorter peptide segments, and the metal chelates of free amino acids and shorter peptide segments can significantly enhance the bioavailability of metal compounds and improve the absorption and utilization rate of nutrients. Adding the above-mentioned specific composition of the composite enzyme based on fermentation is also beneficial to opening the cross-linking state of starch and protein in peanut meal, improving the growth rate and metabolic rate of microorganisms, thereby increasing the yield of organic acids, and organic acids are more conducive to reducing the pH of the animal intestine, inhibiting the growth of harmful bacteria, and improving the activity of digestive enzymes.

[0057] In some embodiments, the amount of cellulase added is 700U / g to 1500U / g; the amount of xylanase added is 700U / g to 1500U / g; the amount of carboxypeptidase added is 1000U / g to 1500U / g; the amount of aminopeptidase added is 1500U / g to 2000U / g. In some embodiments, the treatment temperature of the enzymatic treatment is 37°C to 40°C, and the treatment time is 4h to 5h. Under the above conditions, more free amino acids, monosaccharides or oligosaccharides and organic acids can be obtained.

[0058] S4. The second product is kept warm at a preset temperature to obtain an organic metal chelate for feed.

[0059] In some embodiments, the second product is kept at 55° C. to 60° C. for 60 min to 120 min. Heating can ensure that the subsequent chelation reaction is fully activated, so that the chelation reaction can reach a higher yield in a shorter time. At this temperature and holding time, the chelation rate and chelate yield reach a higher level.

[0060] In summary, the preparation method of the organic metal chelate for feed provided by the present invention is to first mix the peanut meal with the metal compound, and control the fermentation process so that the peanut meal produces more polypeptides and a small part of small peptides and free amino acids during the fermentation process, and the polypeptides are combined with the metal compound to form a macromolecular organic metal chelate for feed, and the small peptides and free amino acids are combined with the metal compound to form a small molecule organic metal chelate for feed. Next, the fermentation product of the peanut meal is further degraded by controlling the enzymatic hydrolysis process to obtain more free amino acids, monosaccharides or oligosaccharides and organic acids, and the above substances are combined with the metal compound to form a small molecule organic metal chelate for feed, and finally the organic metal chelate for compound feed is obtained.

[0061] The present invention is further described below with reference to specific embodiments.

[0062] Example 1

[0063] This embodiment provides an organic metal chelate for feed and a preparation method thereof, comprising the following steps:

[0064] S1, mixing peanut meal and a metal compound to obtain a peanut meal metal compound mixture;

[0065] The mass ratio of the peanut meal to the metal compound is 1000:20; the metal compound is copper sulfate pentahydrate.

[0066] S2, adding water to the peanut meal metal compound mixture, and then inoculating Bacillus subtilis and lactic acid bacteria into the peanut meal metal compound mixture for solid-state fermentation to obtain a first product;

[0067] The material-water ratio is 1:0.75 g / mL, the fermentation temperature is 34° C., the fermentation time is 50 h, the sum of the inoculation amounts of the Bacillus subtilis and the lactic acid bacteria is 10 wt %; the mass ratio of the Bacillus subtilis to the lactic acid bacteria is 1:3.

[0068] S3, adding cellulase, xylanase, carboxypeptidase and aminopeptidase to the first product and performing enzymatic hydrolysis to obtain a second product;

[0069] The added amount of the cellulase is 1200 U / g; the added amount of the xylanase is 1200 U / g; the added amount of the carboxypeptidase is 1100 U / g; the added amount of the aminopeptidase is 1800 U / g, the temperature of the enzymatic treatment is 38° C., and the treatment time is 5 hours.

[0070] S4. The second product is kept at 56° C. for 90 minutes to obtain an organic metal chelate for feed.

[0071] Example 2

[0072] This embodiment provides an organic metal chelate for feed and a preparation method thereof, comprising the following steps:

[0073] S1, mixing peanut meal and a metal compound to obtain a peanut meal metal compound mixture;

[0074] The mass ratio of the peanut meal to the metal compound is 1000:25; the metal compound is ferrous sulfate heptahydrate.

[0075] S2, adding water to the peanut meal metal compound mixture, and then inoculating Bacillus subtilis and lactic acid bacteria into the peanut meal metal compound mixture for solid-state fermentation to obtain a first product;

[0076] The material-water ratio is 1:0.75 g / mL, the fermentation temperature is 34° C., the fermentation time is 50 h, the sum of the inoculation amounts of the Bacillus subtilis and the lactic acid bacteria is 10 wt %; the mass ratio of the Bacillus subtilis to the lactic acid bacteria is 1:3.

[0077] S3, adding cellulase, xylanase, carboxypeptidase and aminopeptidase to the first product and performing enzymatic hydrolysis to obtain a second product;

[0078] The added amount of the cellulase is 1200 U / g; the added amount of the xylanase is 1200 U / g; the added amount of the carboxypeptidase is 1100 U / g; the added amount of the aminopeptidase is 1800 U / g, the temperature of the enzymatic treatment is 38° C., and the treatment time is 5 hours.

[0079] S4. The second product is kept at 56° C. for 90 minutes to obtain an organic metal chelate for feed.

[0080] Example 3

[0081] This embodiment provides an organic metal chelate for feed and a preparation method thereof, comprising the following steps:

[0082] S1, mixing peanut meal and a metal compound to obtain a peanut meal metal compound mixture;

[0083] The mass ratio of the peanut meal to the metal compound is 1000:25; the metal compound is zinc sulfate heptahydrate.

[0084] S2, adding water to the peanut meal metal compound mixture, and then inoculating Bacillus subtilis and lactic acid bacteria into the peanut meal metal compound mixture for solid-state fermentation to obtain a first product;

[0085] The material-water ratio is 1:0.75 g / mL, the fermentation temperature is 34° C., the fermentation time is 50 h, the sum of the inoculation amounts of the Bacillus subtilis and the lactic acid bacteria is 10 wt %; the mass ratio of the Bacillus subtilis to the lactic acid bacteria is 1:2.

[0086] S3, adding cellulase, xylanase, carboxypeptidase and aminopeptidase to the first product and performing enzymatic hydrolysis to obtain a second product;

[0087] The added amount of the cellulase is 1500U / g; the added amount of the xylanase is 700U / g; the added amount of the carboxypeptidase is 1500U / g; the added amount of the aminopeptidase is 1500U / g, the temperature of the enzymatic treatment is 38°C, and the treatment time is 5h.

[0088] S4. The second product is kept at 56° C. for 90 minutes to obtain an organic metal chelate for feed.

[0089] Example 4

[0090] This embodiment provides an organic metal chelate for feed and a preparation method thereof, comprising the following steps:

[0091] S1, mixing peanut meal and a metal compound to obtain a peanut meal metal compound mixture;

[0092] The mass ratio of the peanut meal to the metal compound is 1000:25; the metal compound is manganese sulfate heptahydrate.

[0093] S2, adding water to the peanut meal metal compound mixture, and then inoculating Bacillus subtilis and lactic acid bacteria into the peanut meal metal compound mixture for solid-state fermentation to obtain a first product;

[0094] The material-water ratio is 1:0.75 g / mL, the fermentation temperature is 34° C., the fermentation time is 50 h, the sum of the inoculation amounts of the Bacillus subtilis and the lactic acid bacteria is 10 wt %; the mass ratio of the Bacillus subtilis to the lactic acid bacteria is 1:2.

[0095] S3, adding cellulase, xylanase, carboxypeptidase and aminopeptidase to the first product and performing enzymatic hydrolysis to obtain a second product;

[0096] The added amount of the cellulase is 1500U / g; the added amount of the xylanase is 700U / g; the added amount of the carboxypeptidase is 1500U / g; the added amount of the aminopeptidase is 1500U / g, the temperature of the enzymatic treatment is 38°C, and the treatment time is 5h.

[0097] S4. The second product is kept at 56° C. for 90 minutes to obtain an organic metal chelate for feed.

[0098] Animal tests were conducted on the organic metal chelates for feed obtained in Examples 1 to 4. The specific test contents and results are as follows:

[0099] Experimental animals and treatment

[0100] 960 1-day-old fast-growing Lingnan yellow broilers were selected for the test and randomly divided into 6 groups, each with 8 repetitions, and each with 20 chickens. The experimental group design is shown in Table 1. One group is a negative control group, and three groups are contrast groups (inorganic trace elements): one group is a normal dosage inorganic group (normal inorganic group), one group is a low dosage inorganic group (low inorganic group), and one group is a medium dosage inorganic group (medium inorganic group). Two groups are test groups (organic metal chelates for feed prepared in Example 1): one group is a low dosage organic group (low organic group), and one group is a medium dosage organic group (medium organic group). The test period is 53 days, and it is divided into two stages: chicks (1-21d) and medium-large chickens (22-53d). The measured values ​​of trace elements in the feed of each test group are shown in Table 2. The experiment was terminated when the weight of the test broilers reached about 2 kg. According to the average weight of each replicate pen, two test broilers with a weight close to the average were selected from each pen for slaughter and carcasses. A total of 96 chickens were sampled, and samples of blood, muscle, liver, cecal contents, etc. were collected.

[0101] Table 1 Experimental group design

[0102]

[0103]

[0104] Table 2 Measured values ​​of trace element contents in the diets of different experimental groups (air-dried basis)

[0105]

[0106] Test management and records

[0107] Before the test, clean the feed trough and water trough, thoroughly disinfect the chicken house, perform routine temperature control on the chicken house, and clean up the feces in time. The experimental broilers are fed twice a day. The number of feedings and the amount of feeding are based on the small amount of leftover feed in the feed trough. The feed addition, surplus and loss, and dead chickens of the experimental broilers are accurately recorded every day. All experimental broilers have free access to water and food. The test ends when the weight of the experimental broilers reaches the market weight (about 2kg), and the experimental broilers are slaughtered and sampled.

[0108] Sample collection and slaughter

[0109] Feed was stopped 12 hours before the end of the test period, and the experimental broilers were fasted for 12 hours. The next morning, each pen was weighed. Two experimental broilers with the closest average weight to the treatment group were selected from each pen for slaughter and carcass sampling. Blood was collected from the wing vein. 10 mL of blood was collected from each broiler. After standing for 1 hour, it was centrifuged at 4 ° C and 3 000 rpm for 15 minutes to separate plasma and serum, respectively. After being packaged in 1.5 mL centrifuge tubes, it was stored at -80 ° C for subsequent analysis.

[0110] After bleeding, all slaughtered broilers were bled, and the heads and feet were removed according to the conventional slaughtering method. The carcass traits and meat quality were measured by sampling. The liver, spleen, breast muscle, leg muscle, and abdominal fat were cut on an ice plate and placed in a 1.5 mL centrifuge tube. The right liver and breast muscle were wrapped in tin foil, frozen in liquid nitrogen, and stored at -80 ° C. 3 cm intestinal segments of the anterior duodenum, middle jejunum, and terminal ileum were fixed in 4% formaldehyde solution, and 10 cm of the middle jejunum was cut and the jejunal mucosa was scraped on an ice plate.

[0111] Indicators and measurement methods

[0112] Production performance

[0113] The birds were weighed at the beginning of the experiment, at each stage of cage transfer and at the end of the experiment to calculate the average daily weight gain. The average daily feed intake and feed-to-weight ratio were calculated based on the chicken feeding record sheet.

[0114] Carcass traits

[0115] The carcass traits are determined according to the "Terminology and Measurement Calculation Methods for Poultry Production Performance NY / T823-2020" to determine various indicators such as chicken carcass weight, abdominal fat weight, breast muscle weight, and leg muscle weight.

[0116] Carcass weight: The weight after removing feathers, leg cuticles, toe shells and beak shells. If wet plucking is used, the weight should be drained before weighing.

[0117] Abdominal fat weight: remove abdominal fat and fat around the gizzard.

[0118] Chest muscle weight: strip off the left chest muscle including the pectoralis major, pectoralis minor and third pectoralis muscle, and weigh them × 2.

[0119] Leg muscle weight: all leg muscles after stripping off the leg bone, skin, and subcutaneous fat of the left leg were weighed × 2.

[0120] Organ Index

[0121] The internal organs were removed, the blood was dried with absorbent towels and weighed, and the weights of the heart, liver, spleen, thymus, bursa of Fabricius, etc. were recorded. Organ index (%) = (organ weight / live weight before slaughter) × 100.

[0122] Antioxidant indexes in plasma, liver and muscle

[0123] Total antioxidant capacity (T-AOC) was determined by FRAP method (Cat. No. A015-3-1), malondialdehyde (MDA) was determined by TBA method (Cat. No. A003-2-2), catalase (CAT) was determined by ammonium molybdate method (Cat. No. A007-1-1), superoxide dismutase (SOD) activity was determined by hydroxylamine method (Cat. No. A001-2-2) CuZn-SOD, glutathione peroxidase (GSH-Px) activity was determined by colorimetric method (Cat. No. A005-1-2), all kits were purchased from Nanjing Jiancheng Bioengineering Institute, and the kit instructions were used for determination. Muscle and liver samples were homogenized and centrifuged with 0.9% saline, and 10% homogenate was obtained for detection. Muscle and liver homogenates were tested for protein content using Keygen BCA protein content detection kit (Cat. No. KGP902), and antioxidant activity was expressed as / mg prot.

[0124] Meat quality

[0125] Determine the meat quality properties of broiler muscle including meat color, pH, intramuscular fat, drip loss and cooking loss.

[0126] Meat color determination: Select the thickest part of the left chicken breast near the sternum, with a thickness of about 1 cm, and measure it using a D 65 light source colorimeter (CR-300, Minolta, Japan) at 45 minutes after slaughter, 24 hours after refrigeration, and 48 hours after refrigeration. Spread the meat sample on a horizontal surface, with the meat sample and the grating mouth tightly fitted. Do not push the meat sample too much to deform it. Repeat the measurement at 3 different points on the sample surface and record L * (brightness), a * (redness), b * The yellowness value is read and the arithmetic mean of the results of three repeated measurements is taken.

[0127] pH determination: At 45 minutes after slaughter, 24 hours and 48 hours after refrigeration, the muscle pH was measured using a portable acidity meter (OPTO-STAR, R. Matthaus, Germany) with electrodes inserted into the center of the longissimus dorsi muscle. Repeat the measurement at three different points on the sample, and take the arithmetic mean of the three repeated measurement results.

[0128] Drip loss determination: Within 2 hours after slaughter, take the middle part of the pectoralis major muscle on the left side of the broiler, and cut the sample into 1cm×2cm×2cm long strips along the direction of the muscle fibers. Weigh the weight of the sample before hanging on an electronic balance. Hook one end of the meat strip with a toothpick, so that the muscle fibers are vertically downward, and suspend it in a disposable plastic cup (the meat sample should avoid contact with the cup wall). After sealing the cup mouth with plastic wrap, hang it in the refrigerator, refrigerate at 2-4℃ for 24h and 48h, and take out the meat strip and weigh it. Calculate the drip loss according to the formula: drip loss (%) = (weight before hanging - weight after hanging) / weight before hanging × 100. Two parallel samples are measured for each meat sample, and the arithmetic mean of the results of the two parallel measurements is taken.

[0129] Shear force determination: within 3 hours after slaughter, take the middle part of the pectoralis major muscle on the left side of the broiler, put the meat sample into a clean sealed bag, and then place it in a refrigerator at 4℃ for 96 hours. Take out the matured sample and place it at room temperature for 15 minutes. Open the meat bag, insert the glass thermometer into the center of the meat sample, tie the bag mouth, put it into an 80℃ constant temperature water bath with the bag mouth facing up, cover it and continue heating until the core temperature of the meat sample reaches 70℃. Take out the meat sample, rinse it with tap water for a while to cool it down, and cool it to 20℃ at room temperature. Then take out the meat sample, cut off a 1.5cm thick piece of meat in the direction perpendicular to the muscle fiber, and then use a circular sampler with a diameter of 1cm to cut the meat sample along the direction of the muscle fiber. Cut 10 parallel samples for each meat sample, and cut each parallel sample 3 times, and take the arithmetic mean.

[0130] Cooking loss: Take the left pectoral muscle of a broiler, cut a 1g meat sample from the same part, and cook it in a water bath at 85° for 30 minutes. Cooking loss (%) = [1-(weight after steaming / weight before steaming)] × 100%.

[0131] Intramuscular fat: Take the muscle out of the -80℃ refrigerator and put it into a freeze dryer for freeze drying for 48 hours. Grind the muscle blocks into muscle powder and determine it by Soxhlet extraction method according to the standard "Determination of Fat in Food GB 5009.6-2016".

[0132] Trace element content determination

[0133] The determination of iron, copper, manganese and zinc content in feed, blood, liver, muscle and feces refers to "GB 5009.268-2016 National Food Safety Standard Determination of Multiple Elements in Food".

[0134] Statistical analysis

[0135] After the experimental data were sorted out using Excel 2019, statistical analysis was performed using SPSS (26.0) software. The data were all expressed as the mean and standard error of the mean (SEM). Before evaluating the differences between groups, the Shapiro-Wilk test was used to check the normality of the data. When the variable data were non-normally distributed, Kruskal-Wallis one-way ANOVA analysis was used and multiple corrections were performed using FDR. When the data were normally distributed, one-way ANOVA analysis was used and multiple comparison tests were performed using Duncan. A P < 0.05 was considered significantly different, and 0.05 < P < 0.10 indicated a significant trend.

[0136] Results

[0137] Production performance

[0138] Figure 1 Regarding the effect of the organometallic chelate for compound feed on the growth performance of yellow-feathered broilers, note: Different superscript letters in the same row indicate significant differences (P < 0.05), and the presence of the same letter or no superscript indicates no significant differences (P > 0.05). 0.05 ≤ P < 0.1 indicates a significant trend, and the same applies hereinafter. From Figure 1 it can be seen that the average daily gain (ADG) of the medium and large chicken stages (22 - 53 d) and the whole period (1 - 53 d) in the low-organic group and the medium-organic group were significantly higher than those of other groups (P < 0.05), indicating that the organometallic chelates for feed prepared in Examples 1 - 4 can significantly improve the production performance of yellow-feathered broilers.

[0139] Carcass indexes

[0140] Figure 2 Regarding the effect of the organometallic chelate for compound feed on the carcass traits of yellow-feathered broilers, from Figure 2 it can be seen that there were no significant differences in the carcass trait indexes of yellow-feathered broilers among groups (P > 0.05).

[0141] Organ indexes

[0142] Figure 3 Regarding the effect of the organometallic chelate for compound feed on the organ indexes of yellow-feathered broilers, from Figure 3 it can be seen that compared with the inorganic group, adding low and medium amounts of the organometallic chelate for compound feed could significantly increase the heart index of yellow-feathered broilers (P < 0.05); compared with the low and medium inorganic groups, there was a trend of significantly increasing the liver index and thymus index in the control group and the medium-organic group (0.05 < P < 0.10), while there was no difference in the liver index between the low-organic group and the normal inorganic group (P > 0.05).

[0143] Muscle physical and chemical properties

[0144] Figure 4Effects of organic metal chelates in compound feed on the quality of yellow-feathered broiler meat. Figure 4 It can be seen that the pH value of the breast muscle of yellow-feathered broilers in the low organic group was significantly higher than that in the control group and the low inorganic group at 45 minutes after slaughter (P<0.05); the drip loss of the breast muscle of yellow-feathered broilers in the low inorganic group was the highest, and the low organic group significantly reduced the drip loss of the breast muscle of yellow-feathered broilers 24 hours after slaughter (P<0.05); while the drip loss of the breast muscle of yellow-feathered broilers in the low inorganic group and the control group was significantly higher than that in the organic group 48 hours after slaughter (P<0.001). There were no significant differences in meat quality indicators such as meat color, cooking loss, shear force and intramuscular fat of breast muscle of yellow-feathered broilers among the groups (P>0.05).

[0145] Antioxidant Capacity

[0146] Figure 5 Effects of organic metal chelates in compound feed on antioxidant capacity of yellow-feathered broilers. Figure 5 It can be seen that the concentration of catalase in the plasma of yellow-feathered broilers in the organic group was significantly higher than that in other groups (P<0.05), and the concentration of copper-zinc superoxide dismutase in the plasma of yellow-feathered broilers in the low organic group was significantly higher than that in the inorganic group (P<0.05). The concentration of catalase in the liver of yellow-feathered broilers in the low organic group was significantly higher than that in the inorganic group and the control group (P<0.05), and the concentration of glutathione peroxidase in the medium organic group was significantly higher than that in other groups (P<0.05). There were no significant differences in the antioxidant indexes of the breast muscle of yellow-feathered broilers among the groups (P>0.05).

[0147] Trace element deposition in the body

[0148] Figure 6 Effects of organic metal chelates in compound feed on the deposition of trace elements in yellow-feathered broilers. Figure 6 As shown, compared with the inorganic group with the same dose, the composite trace element treatment could increase the concentration of iron and copper in serum and the deposition of iron, copper in breast muscle and zinc in tibia (P<0.05); there was no significant difference in the deposition of the four elements in the liver of yellow-feathered broilers among the groups (P>0.05).

[0149] Fecal trace element emission

[0150] Figure 7 Effects of organic metal chelates in compound feed on fecal discharge of yellow-feathered broiler chickens, such as Figure 7 As shown, compared with the normal inorganic group, the compound organic trace element treatment group can significantly reduce the discharge of iron, copper, zinc and manganese in the feces of yellow-feathered broiler chickens (P<0.05).

[0151] Intestinal morphology

[0152] Figure 8 Effects of organic metal chelates in compound feed on intestinal morphology of yellow-feathered broilers. Figure 8It can be seen that the depth of duodenal crypts in the control group and low inorganic group of yellow-feathered broilers was significantly higher than that in the organic group (P<0.05), but the ratio of villus height to crypt depth in the organic group was significantly higher than that in the control group (P<0.05). The ratio of villus height to crypt depth in the jejunum of yellow-feathered broilers in the low organic group was significantly higher than that in the control group, normal inorganic group and inorganic group (P<0.05), but there was no significant difference with the medium organic group.

[0153] Changes in intestinal gene expression

[0154] Fig. 9 Effects of organic metal chelates in compound feed on the mRNA expression of tight junction proteins and inflammatory factors in the jejunal mucosa of yellow-feathered broilers. Fig. 9 It can be seen that compared with the low inorganic group, the organic group could significantly increase the mRNA expression levels of Occludin, ZO-1, Claudin-1 and Claudin-5 in the jejunal mucosa of yellow-feathered broilers (P<0.05), and could significantly increase the mRNA expression level of TGF-β in the jejunal mucosa of yellow-feathered broilers (P<0.05), but had no significant effect on the expression level of TNF-α.

[0155] in conclusion

[0156] The preparation method of the organic metal chelate for feed provided by the present invention comprises the following steps: firstly mixing peanut meal with a metal compound, and controlling the fermentation process so that the peanut meal produces more polypeptides and a small part of small peptides and free amino acids during the fermentation process, wherein the polypeptides are combined with the metal compound to form a macromolecular organic metal chelate for feed, and the small peptides and free amino acids are combined with the metal compound to form a small molecular organic metal chelate for feed. Next, the fermentation product of the peanut meal is further degraded by controlling the enzymatic hydrolysis process to obtain more free amino acids, monosaccharides or oligosaccharides and organic acids, and the above substances are combined with the metal compound to form a small molecular organic metal chelate for feed, and finally the organic metal chelate for composite feed is obtained. The above organic metal chelate for feed replaces high doses or equivalent addition amounts of inorganic trace elements, and can significantly improve the production performance, cardiac index, breast muscle quality and antioxidant capacity of yellow-feathered broilers, improve the body's trace element deposition, intestinal immune function, and increase the concentration of iron and copper in serum and the deposition of iron and copper elements in breast muscle and manganese element in tibia, while significantly reducing the discharge of fecal iron, copper, zinc and manganese elements.

[0157] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0158] In addition, the above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An organic metal chelate for feed, characterized in that: The organic metal chelate for feed is obtained by mixing plant protein with a metal compound and subjecting it to fermentation, enzymolysis and chelation treatment. The metal compound is selected from one or more of cupric sulfate pentahydrate, ferrous sulfate heptahydrate, zinc sulfate heptahydrate and manganese sulfate monohydrate.

2. The organic metal chelate for feed according to claim 1, characterized in that: The organic metal chelate for feed comprises iron, copper, zinc and manganese, wherein the mass of zinc: the mass of iron: the mass of copper: the mass of manganese is (45-75): (175-215): (3-10): (95-165).

3. A method for preparing the organic metal chelate for feed as claimed in claim 1 or 2, comprising the following steps: mixing peanut meal and a metal compound to obtain a peanut meal metal compound mixture; adding water to the peanut meal metal compound mixture, and then inoculating Bacillus subtilis and lactic acid bacteria into the peanut meal metal compound mixture for solid-state fermentation to obtain a first product; Add cellulase, xylanase, carboxypeptidase and aminopeptidase to the first product and perform enzymatic hydrolysis to obtain a second product; The second product is kept warm at a preset temperature to obtain an organic metal chelate for feed; The metal compound is selected from one or more of copper sulfate pentahydrate, ferrous sulfate heptahydrate, zinc sulfate heptahydrate and manganese sulfate monohydrate.

4. The method for preparing an organic metal chelate for feed according to claim 3, characterized in that: The added amount of the cellulase is 700U / g to 1500U / g; The added amount of the xylanase is 700U / g to 1500U / g; The added amount of the carboxypeptidase is 1000U / g to 1500U / g; The added amount of the aminopeptidase is 1500U / g to 2000U / g.

5. The method for preparing an organic metal chelate for feed according to claim 3, characterized in that: The enzymatic hydrolysis treatment has a treatment temperature of 37° C. to 40° C. and a treatment time of 4 h to 5 h.

6. The method for preparing an organic metal chelate for feed according to claim 3, characterized in that: The sum of the inoculation amounts of the Bacillus subtilis and the lactic acid bacteria is 8wt% to 11wt%; The mass ratio of the Bacillus subtilis to the lactic acid bacteria is 1:(2-3).

7. The method for preparing an organic metal chelate for feed according to claim 3, characterized in that: The mass ratio of the peanut meal to the metal compound is 1000:(15-25); The material-water ratio of the peanut meal metal compound mixture to water is 1: (0.6-0.9) g / mL.

8. The method for preparing an organic metal chelate for feed according to claim 3, characterized in that: The fermentation temperature of the solid-state fermentation is 31°C to 35°C; The fermentation time of the solid-state fermentation is 48h to 52h.

9. The method for preparing an organic metal chelate for feed according to claim 3, characterized in that: The second product is kept at 55°C to 60°C for 60min to 120min.

10. Use of the organic metal chelate for feed according to claim 1 or 2, characterized in that: The organic metal chelate for feed is applied to feed for yellow-feathered broiler chickens.

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