Egg quality improver and method for producing improved egg

Abstract

To provide an egg quality improving agent that improves the quality of at least one of an effect of improving egg yolk color, an effect of improving egg shell strength, an effect of increasing egg white height, an effect of increasing egg shell thickness, an effect of increasing egg weight, an effect of improving Haugh unit, an effect of improving egg lay rate, and an effect of reducing the incidence of abnormal eggs.SOLUTION: There is provided an egg quality improving agent to be blended with chicken feed or used alone. The improving agent comprises a solid culture of filamentous fungi. Eggs that the chickens that have ingested the improving agent lay attain at least one or more improved qualities among improved egg yolk color, improved egg shell strength, increased egg white height, increased egg shell thickness, increased egg weight, improved Haugh unit, improved egg lay rate, and reduced incidence of abnormal eggs.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an agent for improving egg quality and a method for producing improved egg quality. [Background technology]

[0002] Patent Document 1 describes a method for producing a powder by inoculating steamed rice with red koji (a mutant strain of Monascus pilosus IFO4520), drying and pulverizing the resulting culture. It describes that when this powder is fed to laying hens, it reduces the cholesterol content in egg yolks. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-325110 A Summary of the Invention [Problem to be solved by the invention]

[0004] The powder described in Patent Document 1 improves the quality of chicken eggs by reducing the cholesterol content in the egg yolk. However, Patent Document 1 does not state that the powder has the effect of improving egg yolk color, the effect of improving eggshell strength, the effect of increasing egg white height, the effect of increasing eggshell thickness, the effect of increasing egg weight, the effect of improving Haugh units, the effect of improving egg laying rate, or the effect of reducing the incidence of abnormal eggs.

[0005] The present invention aims to provide an agent for improving egg quality that improves at least one of the following qualities: the effect of improving egg yolk color, the effect of improving eggshell strength, the effect of increasing egg white height, the effect of increasing eggshell thickness, the effect of increasing egg weight, the effect of improving Haugh units, the effect of improving egg laying rate, and the effect of reducing the incidence of abnormal eggs, and a method for producing quality-improved eggs. [Means for solving the problem]

[0006] The above-mentioned problems are solved by an egg quality improver that is used by being mixed with chicken feed or by itself, and contains a solid culture of a filamentous fungus, and improves at least one of the qualities of eggs laid by chickens that have been ingested, including improved egg yolk color, improved eggshell strength, increased egg white height, increased eggshell thickness, increased egg weight, improved Haugh units, improved egg laying rate, and reduced incidence of abnormal eggs.

[0007] The above-mentioned problems are solved by a method for improving egg quality by adding a solid culture of filamentous fungi to chicken feed or feeding the chickens alone, and by providing eggs laid by the chickens having received the solid culture, the eggs have at least one improved quality among improved egg yolk color, improved eggshell strength, increased egg white height, increased eggshell thickness, increased egg weight, improved Haugh unit, improved egg laying rate, and reduced incidence of abnormal eggs. In the method for producing eggs, when the solid culture of filamentous fungi is added to chicken feed for feeding to the chickens, the mixing ratio of the solid culture of filamentous fungi to the feed is preferably 0.1 to 5.0 mass%.

[0008] The filamentous fungus is preferably a non-mycotoxin-producing fungus. The non-mycotoxin-producing fungus is preferably Aspergillus oryzae, Aspergillus sojae, or Aspergillus luchuensis, which does not produce mycotoxins. The solid culture of the filamentous fungus preferably contains polysaccharides constituting mycelium. The solid culture of the filamentous fungus preferably contains an active enzyme. The solid culture of the filamentous fungus preferably contains viable cells of the filamentous fungus. Effect of the Invention

[0009] According to the present invention, it is possible to provide an egg quality improver that improves at least one of the following qualities: the effect of improving egg yolk color, the effect of improving eggshell strength, the effect of increasing egg white height, the effect of increasing eggshell thickness, the effect of increasing egg weight, the effect of improving Haugh units, the effect of improving egg laying rate, and the effect of reducing the incidence of abnormal eggs; and a method for producing quality-improved eggs. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the egg quality improving agent and the method for producing quality-improved eggs (hereinafter simply referred to as the method for producing eggs) will be described.

[0011] The egg quality improving agent of the present invention is used by being added to chicken feed or alone. In the method for producing eggs, the egg quality improving agent may be added to chicken feed and given to the chickens, or may be given to the chickens alone. The effect of improving egg quality can be obtained whether the egg quality improving agent is given to chickens alone without being added to feed, or whether the egg quality improving agent is added to feed and given to chickens. The chicken feed to which the egg quality improving agent is added is not particularly limited, and any known feed can be used.

[0012] The mixing ratio of the egg quality improver and the feed is not particularly limited. However, even if an excessive amount of the egg quality improver is mixed, the effect of improving egg quality tends to saturate, and the cost increases. If the egg quality improver is mixed with the feed so that the mixing ratio (%) of the egg quality improver is, for example, 0.1 to 5.0 mass%, 0.1 to 2.0 mass%, or 0.20 to 1.5 mass%, the effect of improving egg quality can be obtained. Even if the mixing ratio of the egg quality improver is as small as 0.1 mass%, the effect of improving egg quality can be obtained.

[0013] It is preferable to use a non-mycotoxin producing fungus as the above-mentioned filamentous fungus. If the fungus is a non-mycotoxin producing fungus, it is safe for chickens to ingest it. Examples of filamentous fungi that do not produce mycotoxins include filamentous fungi that do not produce mycotoxins, such as Aspergillus oryzae, Aspergillus sojae, and Aspergillus luchuensis. These filamentous fungi are commercially available as seed cultures for fermentation of fermented foods, and can be purchased from the National Institute of Technology and Evaluation, National Biotechnology Center (NBRC). The above-mentioned filamentous fungus may be a wild strain that has not been genetically modified, or may be genetically modified by genetic engineering techniques as described below.

[0014] Examples of mycotoxins include aflatoxin, deoxynivalenol, ochratoxin, fumonisin, zearalenone, patulin, threligmatocystin, and Fusarium toxin.

[0015] The solid culture of the filamentous fungus preferably contains polysaccharides that constitute mycelium. If the filamentous fungus is ingested together with the culture containing polysaccharides, it is expected that the immune system of the chickens that have ingested the filamentous fungus will be improved. As a result, it is expected that the quality of the eggs will also be improved.

[0016] The solid culture of filamentous fungi preferably contains an active enzyme. If the solid culture of filamentous fungi contains an active enzyme, for example, by mixing the solid culture of filamentous fungi with chicken feed, the polymer contained in the feed can be decomposed. Since this decomposition action is performed outside the chicken's body, it does not depend on the chicken's digestive ability and does not put a burden on the chicken. If the active enzyme improves the digestibility of the feed, for example, the feed can be decomposed by the enzyme outside the chicken's body to make it easier for nutrients to be absorbed into the chicken's body, thereby improving feed efficiency. Although the detailed mechanism is unknown, it is speculated that the quality of chicken eggs is improved by making it easier for various nutrients to be absorbed into the chicken's body.

[0017] The solid culture of the filamentous fungus preferably contains viable filamentous fungi. If the solid culture contains viable fungi, the agent for improving egg quality can be easily obtained, for example, by adding a culture substrate described below to the culture and carrying out a secondary culture. According to this method, since there is no need to obtain a seed culture, the agent for improving egg quality can be obtained very easily.

[0018] For example, when the enzyme is cellulase or pectinase, the decomposition enzyme catalyzes a reaction that decomposes cellulose, pectin, etc. contained in feed, etc. Polysaccharides such as cellulose and pectin are a type of component that constitutes the cell wall of plants. Various types of polysaccharides that constitute the cell wall of plants are known, and although they have various forms, their structure is complex. In order to efficiently decompose cell wall polysaccharides with a complex structure, it is preferable to act multiple decomposition enzymes in stages. For example, by decomposing cellulose, pectin, etc. with multiple enzymes such as cellulase and pectinase, the decomposition efficiency of the cell wall of the plant raw material contained in the feed is improved, and the feed becomes easier to digest.

[0019] For example, when the enzyme is tannase, it catalyzes the reaction of decomposing tannins contained in feed. Some tannins bind strongly to polymers such as proteins to form complexes. Tannins also exist in a state where they are intricately entangled with the components that make up the cell walls of plants, and may inhibit the decomposition of the cell walls. By decomposing tannins with tannase, the efficiency of decomposing the cell walls of plant-based raw materials contained in feed is improved, making the feed easier to digest.

[0020] For example, when the enzyme is phytase, it catalyzes a chemical reaction that separates inorganic phosphoric acid from phytic acid contained in feed. Phytic acid is said to inhibit the absorption of minerals such as calcium and zinc contained in feed into the body of the animal that ingests the feed. Therefore, by breaking down phytic acid with phytase, the absorption rate of minerals is improved. In addition, the phosphorus generated by the decomposition of phytic acid can be absorbed by the body of the animal that ingests the feed.

[0021] Examples of the enzyme include one or more enzymes selected from the group consisting of amylase, alkaline protease, acid protease, neutral protease, xylanase, β-glucanase, cellulase, tannase, phytase, lactase, lipase, pectinase such as polygalacturonase, xylanase-pectinase complex enzyme, cellulase-protease-pectinase complex enzyme, etc. All of these enzymes are encoded by the genomic DNA of filamentous fungi and are expressed by wild-type filamentous fungi.

[0022] To obtain a culture having enzymatic activity, a solid culture of a filamentous fungus may be used as an egg quality improver without excessive heating of the culture. Excessive heating refers to heating to an extent that the enzymatic activity is lost. In addition, to obtain a solid culture containing live filamentous fungus, a solid culture of a filamentous fungus may be used as an egg quality improver without excessive heating that would kill the filamentous fungus.

[0023] Using known genetic engineering techniques, filamentous fungi may be transformed so that the above enzymes are highly expressed. In filamentous fungi, for example, the promoter of amylase (AmyB) or the promoter of enolase (enoA) are known to have high expression levels. A gene encoding a target enzyme among the above enzymes and a terminator sequence corresponding to the promoter are linked to these promoters using known techniques to obtain a chimeric gene. By introducing this chimeric gene into filamentous fungi using known methods, a filamentous fungus in which the target enzyme is highly expressed can be obtained. Analysis of the genome sequence of filamentous fungi has already been completed, and the sequence is published in a database. Using such a database, the sequences of the high expression promoter, the terminator, and the gene encoding the target enzyme are examined, and primers are designed. The desired gene sequence can be amplified by PCR using the designed primers and a template such as cDNA or genomic DNA, and used for transformation. During transformation, the chimeric gene may be introduced into a desired position in the genome using a known genome editing technique, or the chimeric gene may be introduced into the cells of the filamentous fungus so that the chimeric gene is introduced into an arbitrary position in the genome. To selectively culture the transformed filamentous fungus, known marker genes such as niaD and ptrA may be used.

[0024] When cloning a gene to be highly expressed, it is preferable to use the genomic DNA or cDNA of the same species of filamentous fungus as the filamentous fungus to be transformed as a template. If the gene to be incorporated into the filamentous fungus to be transformed is derived from a filamentous fungus belonging to the same species, no foreign gene will be incorporated, and the safety of the filamentous fungus will be guaranteed. This type of cloning method is called self-cloning. For example, the desired gene is cloned using the genomic DNA of a wild strain of koji mold (Aspergillus oryzae, RIB40) available from NBRC (National Institute of Technology and Evaluation) as a template. Then, the cloned gene is introduced into a koji mold for sake brewing (Aspergillus oryzae, AOK11) that is commercially available as a koji mold for sake brewing.

[0025] A solid culture of a filamentous fungus can be obtained, for example, by the following method. A solid culture substrate described later is steamed and cooled. A seed fungus is inoculated into the cooled culture substrate. The inoculated culture substrate is piled on the culture bed of a culture device, and culture is performed so that temperature- and humidity-controlled air passes between the particles of the culture substrate, so that the filamentous fungus propagates on the solid culture substrate. The temperature of the air is not particularly limited, but is controlled to be in the range of, for example, 20 to 45° C. The humidity of the air is not particularly limited, but is controlled to be, for example, 50 to 99% relative humidity.

[0026] When filamentous fungi are cultured in a solid state, more types of enzymes are produced and the production amount of each enzyme is greater than when the filamentous fungi are cultured in a liquid state. Therefore, feeding filamentous fungi cultured in a solid state to chickens has a greater effect on improving the quality of chicken eggs than feeding filamentous fungi cultured in a liquid state to chickens. In addition, most chicken feed is solid. In the case of a liquid culture of filamentous fungi, if it is mixed with solid feed, the liquid content of the feed will increase. This may reduce the chickens' palatability. A solid culture of filamentous fungi is preferable because it does not cause such problems.

[0027] The culture substrate may be, for example, a solid organic matter suitable for the growth of filamentous fungi. The solid includes not only hard solid matter but also slurry-like substances or powders. The substrate may be, for example, one or more organic matter selected from the group consisting of grains such as barley, wheat, wheat bran, rice, beans, corn, etc.; food processing residues such as beet pulp, oil cake, and brewed food cake; and food residues such as leftover rice. Examples of oil cake include soybean cake, rapeseed cake, sesame cake, and corn cake. Examples of brewed food cake include sake cake and soy sauce cake. EXAMPLES

[0028] The egg quality improving agent will be described below with reference to examples.

[0029] [Example 1] Wheat bran was added with water and stirred, and then steamed under a condition of 0.2 MPa. The steamed wheat bran was cooled to about 30°C, and a certain amount of Aspergillus oryzae (AOK11), which is commercially available as a koji mold for sake brewing and does not produce mycotoxins, was seeded and mixed uniformly. The moisture content of the wheat bran at the time of seeding was set to 60%. This raw material was placed in the culture bed of the culture device, and the thickness of the piled raw material was equalized to a constant value before starting the culture. During the culture, air with controlled temperature and humidity was supplied to the piled raw material, and the supplied air was allowed to pass between the grains of the raw material. At this time, the temperature of the supplied air was controlled to be 25-40°C and the relative humidity of the supplied air was controlled to be 90-96%, so that the product temperature of the raw material was in the range of 30-38°C. During the culture, the raw material was stirred using a stirring device installed in the culture device. The culture was continued until the surface of the wheat bran particles was covered with mycelium. This solid culture was used as the egg quality improver of Example 1 without sterilization by heating or the like. This egg quality improver contains live Aspergillus oryzae (AOK11) cells and contains enzymes that maintain the activity of useful enzymes of Aspergillus oryzae (AOK11).

[0030] [Example 2] A solid wheat bran culture was obtained in the same manner as in Example 1, except that Aspergillus oryzae (AOK11) in which tannase (tanA), a type of pectinase, pectin lyase (pelA), phytase (phyA), and a type of pectinase, polygalacturonase (pgaB), were highly expressed as the seed culture. This solid culture was used as the egg quality improver of Example 2 without sterilization by heating or the like. This egg quality improver contains live bacteria and maintains enzyme activity, as described above.

[0031] The target genes of tannase (tanA), pectin lyase (pelA), phytase (phyA), or polygalacturonase (pgaB) were inserted into Aspergillus oryzae (AOK11) by a known method, and transformed. When cloning the target genes, the genomic DNA of Aspergillus oryzae (RIB40) was used as a template. Each of the target genes was inserted between the amylase promoter (AmyB promoter) sequence, which is a high expression promoter, and the amylase terminator sequence (AmyB terminator) sequence. These gene sequences can be examined using the Koji mold genome database (http: / / www.aspgd.org / ) and the glucosyl hydrolase database CAZy (http: / / www.cazy.org / fam / acc_GH.html).

[0032] [Effects on hens in the later stages of egg laying] A mixture of the egg quality improvers of Examples 1 and 2 and feed was fed to 325-day-old late-laying chickens (Boris Brown breed) for 24 days (feeding period), and the effect on the quality of eggs collected during that period was examined. For comparison, feed alone was fed for the same period to similarly examine the effect on egg quality (Comparative Example 1). The qualities examined were eggshell color, egg yolk color, eggshell strength (eggshell strength), egg white height, eggshell thickness (eggshell thickness), egg weight, Haugh unit, and egg laying rate. In addition, when each egg quality improver was mixed with feed, the mixing ratio of the egg quality improver was set to 0.25 mass%, 0.5 mass%, and 1.0 mass%, respectively, as shown in Table 1.

[0033] The group that received the sample containing 0.25% by mass of the egg quality improving agent of Example 1 was designated as test group 1, and the group that received the sample containing 0.5% by mass of the egg quality improving agent of Example 1 was designated as test group 2, as shown in Table 1. Test groups 1 to 7 were set up as shown in Table 1. Each test group contained five 325-day-old chickens in the late egg-laying stage.

[0034] The mixing ratio of the egg quality improver is based on the following formula. The feed used was a feed (product name: Gold 18) manufactured by Nishinippon Feed Co., Ltd., containing 52% by mass of grains, 27% by mass of vegetable oil cake, and 15% by mass of other ingredients. The methods of each test are as follows. Mixture ratio of egg quality improver (mass%) = [Mass of egg quality improver ÷ (Mass of egg quality improver + Mass of feed)] x 100

[0035] [Eggshell color] Using a Gen Corporation shell color fan, the color number that most closely matched the eggshell color was recorded. Color numbers range from 1 to 10. Egg collection was conducted for a total of three days during the feeding period, with one egg collected per day from each test plot. For each test plot, the average eggshell color was calculated from the measurements of a total of three eggs. The results are summarized in Table 1.

[0036] [Egg yolk] Using a Roche York Color Fan, the color number that most closely matched the egg yolk color was recorded. Color numbers range from 1 to 15. Egg collection was carried out for a total of three days during the feeding period, with one egg collected per day from each test group. The average egg yolk color was calculated from the measurements of a total of three eggs for each test group. The results are summarized in Table 1.

[0037] [Eggshell strength] The pressure destruction method applies pressure (kg / cm 2 ) was applied and the pressure at which the eggshell cracked was measured. The pressure was applied along the long axis of the egg. Egg collection was carried out for a total of three days during the feeding period, with one egg collected per day from each test group. The average eggshell strength was calculated from the measurements of a total of three eggs for each test group. The results are summarized in Table 1.

[0038] [High egg white] The height (mm) of the thick egg white was measured when the egg was cracked and left to rest on a flat plate. Egg collection was carried out for a total of three days during the feeding period, with one egg collected per day from each test group. The average egg white height was calculated from the measurements of a total of three eggs for each test group. The results are summarized in Table 1.

[0039] [Eggshell thickness] The thickness of the eggshell pieces from which the eggshell membrane had been peeled off was measured using an eggshell thickness gauge. The thickness of the equatorial part of the egg was measured. Egg collection was carried out for a total of three days during the feeding period, with one egg collected per day from each test group. The average eggshell thickness was calculated from the measurements of a total of three eggs for each test group. The results are summarized in Table 1.

[0040] [Egg weight] The mass (g) of the eggs with shells was measured. Egg collection was carried out for a total of three days during the feeding period, with one egg collected per day from each test group. The average egg weight was calculated from the measurements of a total of three eggs for each test group. The results are summarized in Table 1.

[0041] [Hau Unit] Egg collection was carried out for a total of three days during the feeding period, with one egg collected per day from each test group, and the thick albumen height and egg weight were recorded for each egg collection day and test group. These recorded values ​​were then used to calculate the Haugh unit using the following formula. The Haugh unit is an index of egg freshness, with the higher the value, the fresher the egg. The average value of the Haugh unit values ​​obtained over the three times was calculated and is shown in Table 1. TIFF0007659794000001.tif17170H: Rich egg white high G: 32.2 (constant) W: Egg weight (g)

[0042] [Egg laying rate] Each test area was treated as one flock and the egg-laying rate was calculated. The egg-laying rate is the number of eggs laid in a flock in a certain period divided by the number of chickens. Specifically, it was calculated using the following formula. Egg laying rate (%) = number of eggs laid during the period ÷ total number of chickens during the period × 100 The egg-laying rate was examined for any 10-day period during the feeding period, and the number of chicks was 5, the number of chicks that survived during the period in which the egg-laying rate was examined.

[0043] [Table 1]

[0044] As shown in Table 1, compared to the chickens in test group 7 fed the feed of Comparative Example 1, the late-laying chickens in test groups 1 to 6 fed the feed of Example 1 or Example 2 showed improved egg quality in terms of egg yolk color, eggshell strength, egg white height, eggshell thickness, egg weight, and Haugh units. Also, some chickens showed improved egg laying rates. In particular, the eggshell strength of test groups 1 to 6 according to all of the examples showed a quality improvement effect compared to test group 7 of Comparative Example 1.

[0045] [Effects on hens in the final stages of egg laying] A mixture of the egg quality improvers of Examples 1 and 2 and feed was fed to 425-day-old chickens (Boris Brown breed) in the final stage of egg laying for 30 days (feeding period), and the effect on the quality of eggs collected during that period was examined. For comparison, feed alone was fed for the same period to examine the effect on egg quality in the same manner (Comparative Example 1). The qualities examined were eggshell color, egg yolk, eggshell strength (eggshell strength), egg white height, eggshell thickness (eggshell thickness), egg weight, Haugh unit, egg laying rate, and abnormal egg occurrence rate. In addition, when each egg quality improver was mixed with feed, the mixing ratio of the egg quality improver was set to 0.25 mass%, 0.5 mass%, and 1.0 mass%, respectively, as shown in Table 2. In addition, the composition of the feed and the method of each test were basically the same as above. However, in tests other than egg-laying rate and abnormal egg rate, egg collection was carried out a total of five times during the feeding period, with one egg collected per day from each test group. The methods for testing egg-laying rate and abnormal egg incidence rate are as follows. The results of each test are shown in Table 2.

[0046] The group that received the sample containing 0.25% by mass of the egg quality improving agent of Example 1 was designated as test group 8, and the group that received the sample containing 0.5% by mass of the egg quality improving agent of Example 1 was designated as test group 9, as shown in Table 2. Test groups up to 14 were set as shown in Table 2. Each test group included four chickens that were 425 days old and in the final stage of egg laying.

[0047] [Egg laying rate] Each test area was treated as one flock and the egg-laying rate was calculated. The egg-laying rate is the number of eggs laid in a flock in a certain period divided by the number of chickens. Specifically, it was calculated using the following formula. Egg laying rate (%) = number of eggs laid during the period ÷ total number of chickens during the period × 100 The egg-laying rate was examined for any 10-day period during the feeding period, and the number of chicks that survived during the period in which the egg-laying rate was examined was 4.

[0048] [Abnormal egg rate] For each test group, a period was determined, and the number of eggs laid during that period and the number of abnormal eggs during that period were calculated, and the abnormal egg rate was calculated using the following formula. Note that the period for checking abnormal eggs was any 10-day period during the feeding period mentioned above. Abnormal egg rate (%) = number of abnormal eggs during the period ÷ number of eggs laid during the period × 100

[0049] The eggs were judged to be abnormal or normal by visual inspection and palpation when collected. The criteria for determining whether an egg was abnormal are as follows. An egg was judged to be abnormal if it met any of the following criteria. 1. The surface of the eggshell is rough. 2. There is uneven color on the surface of the eggshell. 3. The surface of the eggshell is cracked or chipped. 4. Due to poor eggshell formation, the egg is wrapped in eggshell membrane instead of having a shell. 5. Those whose shape is significantly misshapen. 6. Eggshell color is extremely white (SCF value of 3 or less).

[0050] [Table 2]

[0051] As shown in Table 2, compared to the chickens in test group 14 fed the feed of Comparative Example 1, the egg quality of the final laying hens in test groups 8 to 13 fed the feed of Example 1 or Example 2 was improved in terms of egg yolk color, eggshell strength, egg white height, eggshell thickness, egg weight, Haugh unit, and egg laying rate. It was also found that the incidence rate of abnormal eggs was reduced. In particular, the eggshell strength, egg white height, Haugh unit, and abnormal egg rate were improved in test groups 8 to 13 according to all of the examples compared to test group 14 of Comparative Example 1.

[0052] As described above, according to the present invention, it is possible to provide an egg quality improver that improves at least one quality among improving egg yolk color, improving eggshell strength, increasing egg white height, increasing eggshell thickness, increasing egg weight, improving Haugh units, improving egg laying rate, and reducing the incidence of abnormal eggs, and a method for producing quality-improved eggs.

Claims

1. It is an egg quality improver that is used by mixing with chicken feed or by itself. The quality improver contains a solid culture of a filamentous fungus, not a solid culture of crushed shellfish, the filamentous fungus is non-mycotoxin producing Aspergillus oryzae, The solid culture of the filamentous fungus contains polysaccharides that constitute the mycelium, This egg quality improver improves at least one of the qualities of eggs laid by hens that have been ingested, including improved egg yolk color, improved eggshell strength, increased egg white height, increased eggshell thickness, increased egg weight, improved Haugh unit, improved egg laying rate, and reduced incidence of abnormal eggs.

2. 2. The agent for improving egg quality according to claim 1, wherein the solid culture of the filamentous fungus contains an active enzyme.

3. The agent for improving egg quality according to claim 1, wherein the solid culture of filamentous fungi contains live cells of the filamentous fungi.

4. A method for improving the quality of chicken eggs by adding a solid culture of a filamentous fungus to chicken feed or feeding the chickens with the solid culture alone, The solid culture is a solid culture of a filamentous fungus inoculated on a substrate (excluding crushed shells), the filamentous fungus is non-mycotoxin producing Aspergillus oryzae, The solid culture of the filamentous fungus contains polysaccharides that constitute the mycelium, This method for producing chicken eggs has improved qualities in at least one of the following areas in eggs laid by hens that include improved egg yolk color, improved eggshell strength, increased egg white height, increased eggshell thickness, increased egg weight, improved Haugh unit, improved egg laying rate, and reduced incidence of abnormal eggs.

5. 5. The method for producing quality-improved chicken eggs according to claim 4, wherein the method improves the quality of chicken eggs by adding the solid culture of filamentous fungi to chicken feed and feeding the chickens with the filamentous fungi, and the mixing ratio of the solid culture of filamentous fungi to the feed is 0.1 to 5.0 mass%.

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