Sea urchin gonad enlargement promoter, mixed feed for sea urchins, sea urchin production method, and use in raising of sea urchins

Abstract

[Problem] A need exists for a feed that exhibits a higher gonad enlargement effect than the prior art, makes it possible to shorten the period required for sea urchin production, and makes it possible to reduce the feeding amount. [Solution] A sea urchin gonad enlargement promoter containing a sterol and / or an ester thereof as an active ingredient, a mixed feed for sea urchins containing the sea urchin gonad enlargement promoter, a sea urchin production method including a step in which sea urchins are fed the mixed feed for sea urchins, and the use of a sterol and / or an ester thereof in raising sea urchins.

Description

Sea urchin gonad hypertrophy promoter, formulated feed for sea urchins, method for producing sea urchins, and use in the cultivation of sea urchins

[0001] The present invention relates to a sea urchin gonad hypertrophy promoter, a formulated feed for sea urchins, a method for producing sea urchins, and use in the cultivation of sea urchins.

[0002] The edible part of sea urchins is the gonad, and feeds for enlarging the gonad of sea urchins and aquaculture methods for enlarging the gonad of sea urchins are known. For example, a feed for sea urchin aquaculture that does not contain animal protein but contains proteins derived from seaweed and wheat flour (see Patent Document 1), a feed for sea urchins consisting of a dried product of gelatinized rice in which powdered seaweed is dispersed (Patent Document 2), a method for raising or culturing sea urchins in which leguminous plants are fed to sea urchins (Patent Document 3), a livestock feed for sea urchins containing seaweed and the internal organs of sea urchins or crushed products thereof (Patent Document 4), a feed for sea urchins characterized in that carotenoids are added to a basic feed containing at least an animal and plant protein-containing material and seaweeds (Patent Document 5), etc. can be mentioned.

[0003] Japanese Patent Application Laid-Open No. 2023-101401, Japanese Patent Application Laid-Open No. 2022-149294, Japanese Patent No. 7249026, Japanese Patent Application Laid-Open No. 2016-187337, Japanese Patent Application Laid-Open No. 06-098691 [[ID=I1]]

[0004] The inventor of the present invention has found that by feeding sea urchins a feed that does not contain animal protein but contains proteins derived from seaweed and wheat flour, sea urchins with gonads that are strong in umami and sweetness and low in bitterness can be produced in a short period (see Patent Document 1). On the other hand, there has been a demand for feeds that have a higher gonad hypertrophy effect than the prior art, feeds that can shorten the period required for sea urchin production, and feeds that can reduce the feeding amount.

[0005] It has been known that when sea urchins are fed a feed with a high protein content, their gonads hypertrophy in a short period. However, the problem has been that the gonads of sea urchins grown on feeds with a high protein content are strongly bitter and the commercial value drops. The present invention has been achieved by identifying nutritional components that have an effect of promoting the hypertrophy of sea urchin gonads, which are different from proteins.

[0006] In other words, the present invention provides a sea urchin gonad enlargement promoter comprising sterols and / or their esters as active ingredients. The sea urchin gonad enlargement promoter may contain bird eggs as a source of sterols and / or their esters. Alternatively, the sea urchin gonad enlargement promoter may contain vegetable oil as a source of sterols and / or their esters.

[0007] Another aspect of the present invention provides a compound feed for sea urchins containing sterols and / or their esters. The content of the sterols and / or their esters may be 1 mg / g or more. The compound feed for sea urchins may contain vegetable oil as a source of the sterols and / or their esters. Another compound feed for sea urchins may contain bird eggs as a source of the sterols and / or their esters.

[0008] Another type of sea urchin feed may be a feed containing bird eggs. In such a case, the bird eggs may include egg yolks. The bird eggs contained in the sea urchin feed may be one or more selected from dried whole eggs, dried egg yolks, dried whole eggs and / or dried egg yolk powder, egg oil, egg yolk oil, and powder containing egg oil and / or egg yolk oil. The proportion of the bird eggs may be 1% to 50% by weight.

[0009] Another compound feed for sea urchins is a compound feed for sea urchins that contains cholesterol. In such a compound feed, the cholesterol content in the total sterol content may be 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50% by weight or more but less than 100% by weight.

[0010] Another aspect of the present invention provides a method for producing sea urchins, comprising the step of feeding them a compound feed for sea urchins. Another aspect of the present invention provides the use of sterols and / or their esters in the rearing of sea urchins. Herein, the use may be the use of bird eggs as a source of sterols and / or their esters in the rearing of sea urchins. Alternatively, the use may be the use of vegetable oils as a source of sterols and / or their esters in the rearing of sea urchins.

[0011] By using the sea urchin gonad enlargement promoter of the present invention, a higher enlargement effect on sea urchin gonads than conventional methods can be achieved. By using the gonad enlargement promoter and sea urchin compound feed of the present invention, compared to conventional techniques, effects such as improved yield of edible sea urchins, shortened cultivation period, and / or reduction in the amount of feed required can be obtained. Furthermore, the gonads produced by the present invention have a strong umami and sweetness and less bitterness. In addition, the present invention contributes to improving the profitability of sea urchin aquaculture.

[0012] This graph shows the correlation between the total sterol content in the feed and the mean value of the gonadal index of sea urchins. The error bars in the graph indicate the standard error. This graph shows the mean value of the gonadal index of sea urchins before feeding, and those fed the example and comparative examples. The error bars indicate the standard deviation, and different letters indicate that a significant difference was observed in the GSI after feeding using the Turkey method after one-way ANOVA (p<0.05). This graph shows the mean value of the gonadal index of sea urchins before feeding, and those fed the example and comparative examples. The error bars indicate the standard deviation, and different letters indicate that a significant difference was observed in the GSI after feeding using the Turkey method after one-way ANOVA (p<0.05). This graph shows the mean value of the gonadal index of sea urchins before feeding, and those fed the example and comparative examples. The error bars indicate the standard deviation, and different letters indicate that a significant difference was observed in the GSI after feeding using the Turkey method after one-way ANOVA (p<0.05).

[0013] The present invention will be described in detail below based on embodiments for carrying out the present invention, but the present invention is not limited to these embodiments.

[0014] This invention provides a sea urchin gonad enlargement promoter containing sterols as an active ingredient. The sea urchin gonad enlargement promoter contains sterols as an active ingredient. Sterols are a general term for compounds having a cyclopentanohydrophenanthrene ring. Sterols found in animals are mainly cholesterol, and cholesterol is known as an animal sterol. Plant sterols found in plants are also called phytosterols, and representative plant sterols include brassicasterol, 7-ergostenol, campesterol, isofucosterol, stigmasterol, 7-stigmasterol, β-sitosterol, and avenasterol. Ergosterol is a well-known sterol found in fungi. Triterpene alcohols found in rice bran oil are also a type of sterol.

[0015] Furthermore, the sterol, which is the active ingredient in the sea urchin gonad enlargement promoter, may also be a derivative of sterol. Examples of sterol derivatives include esters of sterol. Examples of esters of sterol include esters of sterol and fatty acids, and esters of sterol and ferulic acid. Sterol glycosides, in which sterol is bound to sugar, are also examples of sterol derivatives.

[0016] A sea urchin gonad enlargement promoter containing sterols and / or derivatives thereof, when administered to sea urchins, promotes gonad enlargement within the sea urchin's body. Examples of administration routes to sea urchins include intracoelal administration, transdermal administration, and oral administration. In the case of oral administration, the sea urchin gonad enlargement promoter of the present invention can be given directly to sea urchins, or to sea urchins given a compound feed containing the sea urchin gonad enlargement promoter, and the sea urchin gonad enlargement promoter can be administered orally to the sea urchins by ingesting the sea urchin gonad enlargement promoter or the compound feed.

[0017] One embodiment of the gonad enlargement promoter may contain bird eggs as a sterol source. The bird eggs are preferably edible and / or feed eggs, and include eggs from chickens, quail, ducks, geese, turkeys, pigeons, pheasants, ostriches, emus, etc. In this embodiment, chicken eggs are preferably used among bird eggs.

[0018] Since bird eggs are used as a source of sterols, and more specifically, cholesterol, it is preferable that the bird eggs contain at least egg yolk. The bird eggs contained in the gonad enlargement promoter may be, for example, dried whole eggs, dried egg yolks, or powders thereof. Alternatively, the bird eggs contained in the gonad enlargement promoter may be egg oil, egg yolk oil, or powders containing these, obtained by extracting from whole eggs or egg yolks.

[0019] One embodiment of the gonad enlargement promoter may contain plants as a sterol source. The plants that serve as the plant sterol source are edible and / or feed plants, and specifically, rice, brown rice, wheat, legumes, vegetables, fruits, their powders, vegetable oils extracted from them, or powders containing vegetable oils extracted from them are used.

[0020] Examples of vegetable oils used as sources of sterols include rice bran oil, rapeseed oil, soybean oil, corn oil, sunflower seed oil, and peanut oil. Furthermore, concentrates of plant sterols produced from vegetable oils are also an example of vegetable oils. One example of a concentrate of plant sterols is obtained by deacidifying and distilling vegetable oils.

[0021] This invention provides compound feed for sea urchins. Compound feed refers to a product made by forming multiple raw materials into pellets, and is called dry pellets (DP), extruded pellets (EP), etc., depending on the molding method. Compound feed for sea urchins has properties that match the feeding behavior of sea urchins, and specifically has properties such as sinking in seawater and maintaining its shape for a certain period of time in seawater.

[0022] This invention provides a compound feed for sea urchins containing sterols. Sterols are a general term for compounds having a cyclopentanohydrophenanthrene ring. Sterols found in animals are mainly cholesterol, which is known as an animal sterol. Plant sterols found in plants are also called phytosterols, and representative plant sterols include brassicasterol, 7-ergostenol, campesterol, isofucosterol, stigmasterol, 7-stigmasterol, β-sitosterol, and avenasterol. Ergosterol is a well-known sterol found in fungi. Triterpene alcohols found in rice bran oil are also a type of sterol.

[0023] Total sterols are defined as the sum of the contents of representative sterols. In this specification, total sterols refer to the sum of the contents of cholesterol, brassicasterol, 7-ergostenol, campesterol, isofucosterol, stigmasterol, 7-stigmasterol, β-sitosterol, and avenasterol.

[0024] In the present invention, the sterol content of the compound feed may be defined as the content of individual sterols such as cholesterol, β-sitosterol, campesterol, and isofucosterol, or as the total sterol content.

[0025] The sterol-containing compound feed for sea urchins of the present invention may be manufactured by compounding highly purified sterols with other raw materials, but it can also be manufactured by compounding a raw material that serves as a sterol source with other raw materials.

[0026] In one embodiment, the compound feed for sea urchins may contain plant-based raw materials as a source of sterols. As plant-based raw materials that serve as a source of plant sterols, rice, brown rice, wheat, legumes, vegetables, fruits, their powders, vegetable oils extracted from them, or powders containing vegetable oils can be used.

[0027] Examples of vegetable oils used as sources of sterols include rice bran oil, rapeseed oil, soybean oil, corn oil, sunflower seed oil, and peanut oil. Furthermore, concentrates of plant sterols produced from vegetable oils are also an example of vegetable oils. One example of a concentrate of plant sterols is obtained by deacidifying and distilling vegetable oils.

[0028] Another aspect of the present invention provides a compound feed for sea urchins containing bird eggs. The bird eggs incorporated into the compound feed are preferably eggs intended for food and / or feed, and include eggs from chickens, quail, ducks, geese, turkeys, pigeons, pheasants, ostriches, emus, and the like. In this embodiment, chicken eggs are preferred among the bird eggs.

[0029] In compound feed for sea urchins that contains bird eggs, the bird eggs are used as a source of sterols, more specifically, a source of cholesterol, so it is preferable that the bird eggs contain at least egg yolk. The bird eggs contained in the compound feed for sea urchins may be, for example, dried whole eggs, dried egg yolks, or powders thereof. Alternatively, the bird eggs contained in the compound feed for sea urchins may be egg oil, egg yolk oil, or powders containing these extracted from whole eggs or egg yolks.

[0030] In one embodiment, the proportion of bird eggs in the compound feed for sea urchins is 1-50% by weight, 2-30% by weight, and 5-10% by weight. Since compound feed is mainly manufactured from dried powder, the proportion is expressed as a value per dry weight. That is, in one embodiment, the proportion of bird eggs in the compound feed for sea urchins is 1-50% by weight (per dry weight), 2-30% by weight (per dry weight), and 5-10% by weight (per dry weight).

[0031] In one embodiment, the compound feed for sea urchins contains little to no animal protein other than bird eggs. Animal protein refers to the protein contained in raw materials derived from animals (animal raw materials). General compound feeds contain protein-rich animal raw materials in order to increase the protein content in the feed. Examples of protein-rich animal raw materials include fish meal, fish meat, casein, chicken meal, feather meal, insect meal, collagen, etc., but one embodiment of the compound feed for sea urchins of the present invention contains little to no of these animal raw materials.

[0032] A compound feed that contains little to no animal protein other than poultry eggs means a compound feed that does not contain animal-derived ingredients used for the purpose of providing animal protein. Therefore, it is permissible for feed ingredients or feed additives (e.g., pigments, vitamins, minerals, amino acids, etc.) to contain animal-derived ingredients for purposes other than providing animal protein, such as using animal-derived ingredients as excipients and / or stabilizers. Specific examples of animal-derived ingredients used as excipients and / or stabilizers include gelatin, lactose monohydrate, and animal glycerin.

[0033] If compound feed contains animal-derived ingredients for purposes other than providing animal protein, the proportion of animal-derived ingredients may be, for example, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.5% by weight or less, or 0.1% by weight or less.

[0034] Even if animal-derived ingredients are used, it is permissible for the sea urchin feed formulation of the present invention to include ingredients that do not substantially contain protein, such as animal fats and oils like fish oil, beef tallow, and pork tallow. Since fish oil is rich in omega-3 fatty acids, which are important nutrients for sea urchins, its inclusion in sea urchin feed formulations is permissible.

[0035] Furthermore, in one embodiment of the compound feed for sea urchins, no plant-based feed ingredients with a high protein content are added other than seaweed and wheat flour. Specifically, examples of plant-based feed ingredients with a high protein content include corn gluten meal and defatted soybeans (soybean meal). In other words, in one embodiment of the compound feed of the present invention, ingredients derived from corn or soybeans, such as corn gluten meal and defatted soybeans, that have a high protein content are not added. Specifically, ingredients with a high protein content refer to ingredients that contain 30% or more protein by weight per dry weight, ingredients that contain 40% or more protein by weight per dry weight, or ingredients that contain 50% or more protein by weight per dry weight.

[0036] In one embodiment of a compound feed for sea urchins containing bird eggs, the compound feed for sea urchins substantially contains no protein other than seaweed, wheat flour, and bird eggs. In this compound feed, the ingredients other than seaweed, wheat flour, and bird eggs are mainly composed of ingredients that do not contain protein and / or have a low protein content, and ingredients containing protein are included in a very small proportion. Specifically, ingredients that do not contain protein or have a low protein content include oils and fats, carbohydrates such as starch, cellulose, and carboxymethylcellulose (CMC), and inorganic substances such as salt (sodium chloride), calcium chloride, magnesium chloride, and phosphorus. Minerals, vitamins, and pigments can also be included.

[0037] In one embodiment, the protein content of the compound feed for sea urchins can be 3% to 20% by weight, 5% to 15% by weight, or 7% to 10% by weight per dry weight (all per dry weight). If the protein content is lower than the above range, a sufficient effect of promoting gonad enlargement may not be obtained, while if the protein content is high, the gonads obtained from the fed sea urchins may develop a bitter taste.

[0038] In one embodiment of a compound feed for sea urchins containing bird eggs, seaweed, wheat flour, and bird eggs are used as the main protein sources, and the total protein in the feed is mainly composed of proteins derived from seaweed, wheat flour, and bird eggs. For example, whole egg powder and egg yolk powder have a protein content of 40-50% by weight (per dry weight), which is higher than that of seaweed and wheat flour. Therefore, in a compound feed for sea urchins that contains whole egg powder and / or egg yolk powder as bird eggs, the protein derived from bird eggs accounts for a certain proportion of the total protein in the feed.

[0039] In this embodiment, since no ingredients with a higher protein content than whole egg powder or egg yolk powder are included, the proportion of protein derived from whole egg powder or egg yolk powder in the total protein of the feed becomes larger. For example, in a compound feed for sea urchins, protein derived from bird eggs may account for 20-60% or 25-50% by weight of the total protein of the feed. Here, protein derived from bird eggs may be protein derived from whole egg powder and / or egg yolk powder.

[0040] On the other hand, compound feed for sea urchins that contains egg oil and / or egg yolk oil as bird eggs contains little to no protein derived from bird eggs. This is because egg oil and / or egg yolk oil contain little to no protein.

[0041] One embodiment of the compound feed for sea urchins contains sterols. The total sterol content in the feed may be 1, 1.5, or 2 mg / g or more. The sterols may be animal sterols or plant sterols. The compound feed can contain sterols by incorporating the above-mentioned sterol source into the compound feed. From the examples, a compound feed containing 1 mg / g, preferably 1.5 mg / g of total sterols, was confirmed to have a high effect in promoting gonad enlargement.

[0042] The formulated feed for sea urchins of one embodiment contains cholesterol. The cholesterol content in the feed can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 mg / g or more. By incorporating the above-described cholesterol source into the formulated feed, the formulated feed contains cholesterol.

[0043] When the formulated feed for sea urchins contains cholesterol, the proportion of cholesterol in the total sterols in the feed is 20, 30, 40, 50, 60, 70, 80, or 90% by weight or more, and less than 100% by weight. From the examples, it is considered that cholesterol has a higher promoting effect on gonad hypertrophy than other sterols, and when cholesterol occupies 50% by weight or more of the total sterols in the feed, a particularly high promoting effect on gonad hypertrophy was confirmed.

[0044] Furthermore, the present invention provides a method for producing sea urchins. The method for producing sea urchins includes the step of feeding the above-described formulated feed to sea urchins. In the method for producing sea urchins of one embodiment, sea urchins with a low edible portion yield are used. Preferably, the average edible portion yield of the sea urchins before feeding is 10% by weight or less, and can be 9, 8, 7, 6, 5, 4, 3% by weight or less. The period required for production is 1 to 6 months, preferably 1 to 3 months. By feeding once to three times a week, preferably once or more a week, and feeding three to twenty-four times, preferably about four to six times during the cultivation period, sea urchins with an average edible portion yield of 10% by weight or more, preferably 15% by weight or more can be produced.

[0045] Furthermore, the present invention can be the use of sterols and / or their ester forms in the cultivation of sea urchins. Sterols and / or their ester forms are used for the purpose of gonad hypertrophy of sea urchins in the cultivation of sea urchins. Sterols and / or their ester forms are used for sea urchins by intracoelomic, percutaneous, and / or oral administration.

[0046] When a sterol and / or its ester form is orally administered to sea urchins, in one embodiment, the sterol and / or its ester form is fed to the sea urchins as it is. The sterol and / or its ester form is orally administered to the sea urchins when the sea urchins ingest the sterol and / or its ester form.

[0047] When a sterol and / or its ester form is orally administered to sea urchins, in one embodiment, the sterol and / or its ester form is fed to the sea urchins as a formulated feed containing the sterol and / or its ester form. The sterol and / or its ester form is orally administered to the sea urchins when the sea urchins ingest the formulated feed.

[0048] Further, the present invention can be used in the cultivation of sea urchins as a source of a sterol and / or its ester form. The source of the sterol and / or its ester form is a plant or animal rich in the sterol and / or its ester form. The source is used to administer the sterol and / or its ester form to sea urchins.

[0049] When the source is a plant, rice, brown rice, wheat, beans, vegetables, fruits, their powders, vegetable oils extracted from them, powders containing vegetable oils, and / or concentrates of plant sterols produced from vegetable oils are used.

[0050] When the source is an animal, it can be a bird egg. Among bird eggs, chicken eggs are preferably used. Since bird eggs are used as a sterol source, more specifically a cholesterol source, it is preferably to contain at least egg yolk. For example, it can be dried whole eggs, dried egg yolks, their powders, egg oil or egg yolk oil extracted from whole eggs or egg yolks, and / or powders containing them.

[0051] These sources are used by feeding them to sea urchins as they are or as a formulated feed in which the source is formulated. The sterol and / or its ester form is orally administered to the sea urchins when the sea urchins ingest the source as it is or the formulated feed in which the source is formulated.

[0052] The moisture, protein, lipid, and ash content values ​​of the compound feed of the present invention and the feed ingredients incorporated into the compound feed are obtained by analytical methods specified in the Feed Analysis Standards (Director-General of the Consumer and Food Safety Bureau, Ministry of Agriculture, Forestry and Fisheries, Japan). As an example of the protein and other components of the aquaculture feed of the present invention, the moisture content is 3% to 25% by weight per total weight, the protein is 3% to 15% by weight per dry weight, the lipid content is 1% to 5% by weight per dry weight, and the ash content is 10% to 30% by weight per dry weight.

[0053] The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0054] Preparation of compound feed for sea urchins and sea urchin rearing trials using said compound feed (1)

[0055] Examples and comparative examples of compound feed for sea urchins were prepared. Table 1 shows the composition and protein measurements of the examples and comparative examples. Examples 1 and 2 contained cholesterol (Nacalai Tesque Co., Ltd., Nacalai Grade Special). Examples 3 and 4 used rice sterol ester (Tsukuno Foods Industry Co., Ltd.) as the source of plant sterols. Rice sterol ester is a powder mainly composed of esters of plant sterols and triterpene alcohols with fatty acids, and also contains free fatty acids and anhydrous silicic acid.

[0056] Table 2 shows the sterol content of the examples and comparative examples, calculated from the sterol content of the raw materials used in the examples and comparative examples. Here, the total sterol content is defined as the sum of the content of cholesterol, brassicasterol, campesterol, β-sitosterol, isofucosterol, stigmasterol, avenasterol, 7-stigmasterol, and 7-ergostenol, which are known as major sterols (the same applies hereafter).

[0057] The limit of quantification for each sterol is 1 mg / 100g, but due to the presence of measurement inhibitors, the limit of quantification for brassicasterol in rice sterol esters was 10 mg / 100g, and 7-stigmastenol, 7-ergostenol, and avenasterol in rice sterols could not be analyzed. The amount of sterols in the feed was calculated by treating the content of sterols below the limit of quantification and those that could not be analyzed as zero.

[0058] The feed ingredients listed in the table were mixed with an appropriate amount of water, formed into a cylindrical shape with a diameter of approximately 2 cm, steamed in a steamer for 10 minutes, cut into discs approximately 1 cm thick, and dried overnight or longer in a hot air dryer at 70°C to obtain compound feed. The amount of protein contained in the compound feed was measured using the Kjeldahl method. The protein conversion factor was set to 6.25.

[0059] As shown in the table below, the protein content was almost the same for all feeds. In addition, the cholesterol content in the total sterols of the feeds in Examples 1 and 2 was high, at over 60% by weight. Since the feeds in Examples 3 and 4 contained 5-10% by weight of rice sterols, the cholesterol content in the total sterols of these feeds was relatively low.

[0060]

[0061]

[0062] A rearing experiment was conducted using sea urchins (average shell diameter 56.9 mm, average weight 78.0 g) collected in Setana Town, Hokkaido. The sea urchins were placed in 60 L rectangular tanks and fed 5-6 times a week, with an amount of approximately 12% of their body weight per week, adjusted based on the amount of leftover food. Feeding was discontinued after 10 weeks. The seawater temperature during the rearing period ranged from 10.9 to 14.6°C. Four individuals from each group were dissected to obtain the Gross Gonadal Index (GSI).

[0063] Figure 1 shows the correlation between the average GSI at the end of each group and the total sterol content of the compound feed provided. 2The value was 0.8156, indicating a very strong correlation between the two. Therefore, it was shown that sterols can be used as an active ingredient in sea urchin gonad enlargement promoters.

[0064] Preparation of compound feed for sea urchins and sea urchin rearing trials using said compound feed (2)

[0065] Eggs were boiled in boiling water, the shells were removed, and the eggs were dried and powdered to obtain whole egg powder. Diethyl ether was used to extract the oil that dissolves in diethyl ether from the whole egg powder. Four times the weight of diethyl ether was added to the whole egg powder and stirred for 9 hours, and the solids were removed using filter paper to obtain the liquid. Diethyl ether was removed from the liquid using an evaporator to obtain egg oil. The obtained egg oil was 15.1% by weight of the whole egg powder.

[0066] Examples and comparative examples of compound feed for sea urchins were prepared using whole egg oil and other raw materials in the same manner as in (1). Table 3 shows the composition and protein measurements of the examples and comparative examples. Examples 7 and 8 incorporated rice sterol ester (manufactured by Tsukuno Foods Industry Co., Ltd.) as a source of plant sterols. Table 4 shows the results of measuring the amount of sterols contained in the feed using gas chromatography. The limit of quantification is 1 mg / 100g, but due to the presence of measurement inhibitors, the limits of quantification for 7-stigmastenol and 7-ergostenol were 10 mg / 100g in Example 7 and 5 mg / 100g in Example 8. In addition, avenasterol in Examples 7 and 8 could not be analyzed. In the table, "-" indicates that the value is below the limit of quantification.

[0067]

[0068]

[0069] A rearing experiment was conducted using sea urchins (average shell diameter 50.5 mm, average weight 49.4 g) collected in Setana Town, Hokkaido. The sea urchins were placed in 60 L rectangular tanks and fed 5 to 6 times a week, with an amount of approximately 12% of their body weight per week, adjusted based on the amount of leftover food. Feeding was discontinued after 5 weeks. The seawater temperature during the rearing period ranged from 12.7 to 17.2°C. After the end of feeding, feeding was stopped for one week, and 14 individuals from each group were dissected to obtain the Gross Gonadal Index (GSI).

[0070] The sea urchins used in this study included both healthy and unhealthy individuals, and it was suggested that the unhealthy sea urchins were not feeding. Therefore, the top 9 individuals in each group based on GSI were selected. Figure 2 shows the average values ​​of the top 9 individuals in each group based on GSI. Although the feeding period in (1) was set to 10 weeks, the feeding period in this study was 5 weeks, yet many individuals in the example showed a GSI exceeding 10% by weight.

[0071] Furthermore, the GSI tended to be higher in the group fed a diet with a high sterol content. In particular, Examples 5 and 6, which were fed a diet containing egg oil, showed a significant increase in GSI compared to the comparative example, indicating that cholesterol is highly effective among sterols.

[0072] Preparation of compound feed for sea urchins and sea urchin rearing trials using said compound feed (3)

[0073] Using whole egg powder (Kewpie Egg Co., Ltd.) as a cholesterol source, examples and comparative examples of compound feed for sea urchins were prepared in the same manner as in (1). Table 5 shows the composition and protein measurements of the examples and comparative examples. The protein content of whole egg powder was 46% by weight, and the protein content of wheat flour and seaweed powder was 12% by weight. Therefore, the protein content derived from whole egg powder in the examples was calculated to be 32% to 50% by weight.

[0074] Table 6 shows the sterol content of the examples and comparative examples, calculated from the sterol content of the raw materials used in the examples and comparative examples. The limit of quantification for each sterol was 1 mg / 100g, and the amount of sterols below the limit of quantification was treated as zero to calculate the amount of sterols in the feed. The percentage of cholesterol in the total sterol amount of the examples was calculated to be between 76% and 91% by weight.

[0075]

[0076]

[0077] A rearing experiment was conducted using sea urchins (average shell diameter 53.9 mm, average weight 71.5 g) collected in Setana Town, Hokkaido. The sea urchins were placed in 60 L rectangular tanks and fed 5 to 6 times a week, with an amount of approximately 12% of their body weight per week, adjusted based on the amount of leftover food. Feeding was discontinued after 5 weeks. The seawater temperature remained within the range of 12.5 to 16.1°C during the rearing period. After the end of feeding, feeding was stopped for one week, and 14 individuals from each group were dissected to obtain the Gonadal Index (GSI).

[0078] Figure 3 shows the average GSI values ​​for each group. The groups fed with Examples 9 and 10, which contained whole egg powder, showed a significant increase in GSI compared to the comparative example. Despite the feeding period being only 5 weeks, many individuals in Examples 9 and 10 showed a GSI of 15% by weight or more, which is an indicator of high-quality sea urchins. Furthermore, the gonads obtained in Examples 9 and 10 had strong umami and sweetness, and almost no bitterness, indicating that high-quality sea urchin gonads were obtained in these examples.

[0079] Preparation of compound feed for sea urchins and sea urchin rearing trials using said compound feed (4)

[0080] Using egg yolk powder (provided by Kewpie Corporation) as a cholesterol source, examples and comparative examples of compound feed for sea urchins were prepared in the same manner as in (1). Table 7 shows the composition and protein measurements of the examples and comparative examples. The protein content of egg yolk powder was 35% by weight, and the protein content of wheat flour and seaweed powder was 12% by weight. Therefore, the protein content derived from egg yolk powder in the examples was calculated to be 26% to 44% by weight.

[0081] Table 6 shows the sterol content of the examples and comparative examples, calculated from the sterol content of the raw materials used in the examples and comparative examples. The limit of quantification for each sterol was 1 mg / 100g, and the amount of sterols in the feed was calculated by treating the sterol content below the limit of quantification as zero. The percentage of cholesterol in the total sterol amount of the examples was calculated to be between 80% and 93% by weight.

[0082]

[0083]

[0084] A rearing experiment was conducted using sea urchins (average shell diameter 52.1 mm, average weight 54.9 g) collected in Setana Town, Hokkaido. The sea urchins were placed in 60 L rectangular tanks and fed 5 to 6 times a week, with an amount of approximately 12% of their body weight per week, adjusted based on the amount of leftover food. Feeding was discontinued after 5 weeks. The seawater temperature during the rearing period ranged from 13.6 to 21.4°C. After the end of feeding, feeding was stopped for one week, and 15 individuals from each group (7 individuals for Comparative Example 3) were dissected to obtain the Gross Gonadal Index (GSI).

[0085] Figure 4 shows the average GSI values ​​for each group. The groups fed with Examples 11 and 12, which contained egg yolk powder, showed a significant increase in GSI compared to the comparative example. Despite the feeding period being only 5 weeks, many individuals in Examples 11 and 12 showed a GSI of 15% by weight or more, which is an indicator of high-quality sea urchins. Furthermore, the gonads obtained in Examples 11 and 12 had strong umami and sweetness, and almost no bitterness, indicating that high-quality sea urchin gonads were obtained in these examples.

[0086] The present invention further encompasses the following embodiments: [Embodiment 1] A sea urchin gonad enlargement promoter comprising sterols and / or their esters as an active ingredient. [Embodiment 2] The sea urchin gonad enlargement promoter according to Embodiment 1, wherein the source of the sterols and / or their esters is a bird egg. [Embodiment 3] The sea urchin gonad enlargement promoter according to Embodiment 1 or 2, wherein the source of the sterols and / or their esters is a vegetable oil. [Embodiment 4] A compound feed for sea urchins containing the sea urchin gonad enlargement promoter according to any one of Embodiments 1 to 3. [Embodiment 5] A compound feed for sea urchins containing a bird egg. [Embodiment 6] The compound feed for sea urchins according to Embodiment 5, wherein the bird egg contains egg yolk. [Embodiment 7] The compound feed for sea urchins according to Embodiment 5 or 6, wherein the bird egg is one or more selected from dried whole egg, dried egg yolk, dried whole egg and / or dried egg yolk powder, egg oil, egg yolk oil, and powder containing egg oil and / or egg yolk oil. [Aspect 8] A compound feed for sea urchins according to any one of aspects 5 to 7, wherein the proportion of the bird eggs in the compound is 1% to 50% by weight. [Aspect 9] A compound feed for sea urchins containing sterols and / or their esters. [Aspect 10] A compound feed for sea urchins according to aspect 9, wherein the sterol is cholesterol. [Aspect 11] A compound feed for sea urchins according to aspect 10, wherein the cholesterol content in the total sterols is 50% or more and less than 100% by weight. [Aspect 12] A compound feed for sea urchins according to any one of aspects 9 to 11, wherein the sterol and / or their esters content is 1 mg / g or more. [Aspect 13] A compound feed for sea urchins according to any one of aspects 9 to 12, wherein the vegetable oil is used as a source of the sterols and / or their esters. [Aspect 14] A method for producing sea urchins, comprising the step of feeding sea urchins the compound feed for sea urchins according to any one of aspects 5 to 13. [Aspect 15] Use of sterols and / or their esters in the cultivation of sea urchins. [Aspect 16] Use of bird eggs as a source of sterols and / or their esters in the cultivation of sea urchins. [Aspect 17] Use of vegetable oils as a source of sterols and / or their esters in the cultivation of sea urchins.

Claims

1. A sea urchin gonad enlargement promoter containing sterols and / or their esters as active ingredients.

2. A sea urchin gonad enlargement promoter containing bird eggs.

3. A sea urchin gonad enlargement promoter containing vegetable oil.

4. A compound feed for sea urchins containing the sea urchin gonad enlargement promoter described in any one of claims 1 to 3.

5. A method for producing sea urchins, comprising the step of feeding sea urchins with the sea urchin compound feed described in claim 4.

6. A compound feed for sea urchins containing bird eggs, wherein the bird eggs are one or more selected from dried whole eggs, dried egg yolks, dried whole eggs and / or dried egg yolk powder, egg oil, egg yolk oil, and powder containing egg oil and / or egg yolk oil.

7. The compound feed for sea urchins according to claim 6, wherein the proportion of the bird eggs in the mixture is 1% to 50% by weight.

8. The compound feed for sea urchins according to claim 6, which contains sterols and / or their esters.

9. The compound feed for sea urchins according to claim 8, wherein the sterol is cholesterol.

10. The compound feed for sea urchins according to claim 9, wherein the cholesterol content in the total sterols is 50% by weight or more and less than 100% by weight.

11. The compound feed for sea urchins according to claim 8, wherein the content of the sterol and / or its ester is 1 mg / g or more.

12. The compound feed for sea urchins according to claim 6, further containing vegetable oil.

13. A method for producing sea urchins, comprising the step of feeding sea urchins with a compound feed for sea urchins described in any one of claims 6 to 12.

14. Use of sterols and / or their esters in the enlargement of sea urchin gonads.

15. Use of bird eggs in the enlargement of sea urchin gonads.

16. Use of vegetable oils in promoting gonad enlargement in sea urchins.

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