Feed for farmed fish and shellfish and method for producing the same

Abstract

The present invention provides a feed for farmed fish and shellfish that can be stored and fed at room temperature while using alcohol fermentation residues such as sake lees, and that can improve the taste of farmed fish and shellfish, as well as a method for producing the same. [Solution] The present invention provides a feed for farmed fish and shellfish used in aquaculture, which contains a lactic acid fermentation product obtained by fermenting alcohol fermentation residue with lactic acid bacteria. Such a feed for farmed fish and shellfish can be produced by fermenting a fermentation substrate containing protein and oil using a first fermentation liquid produced by fermenting alcohol fermentation residue with lactic acid bacteria.

Description

Technical Field

[0001] The present invention relates to a feed for cultured fish and shellfish and a method for producing the same, and particularly relates to a feed for cultured fish and shellfish produced using alcohol fermentation residue and a method for producing the same.

Background Art

[0002] The demand for fishery resources is increasing globally, and accordingly, the development of aquaculture technologies for stably supplying aquatic organisms is underway. For the aquaculture of freshwater fish such as rainbow trout, ayu, and koi, and seawater fish such as red sea bream, a feed for cultured fish and shellfish is essential for growing the target fish and shellfish.

[0003] Such feeds for cultured fish and shellfish are mainly developed from the viewpoints of the growth rate and feed efficiency of the target fish and shellfish, but technologies focusing on improving the taste of cultured fish and shellfish have also been proposed. For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2021-10862), the fat content of the edible part has a great influence on the taste in edible fish, and in some fish species, the higher the fat content, the better the taste and the higher the commercial value. Therefore, a feed having an effect of improving the fat content of the fish body is proposed. Specifically, it contains one or two to five of soy sauce oil, beer lees, bitterling, loach, and silver carp fry, the total of these content percentages is 5% to 70%, optionally contains rice bran and sake lees, and proposes a feed for culturing edible fish having an effect of increasing the fat content of the edible part of the edible fish.

[0004] Furthermore, feed for farmed fish and shellfish uses protein sources as essential components for the growth of the fish and shellfish, and this protein source is fishmeal, which is made by drying and crushing fish such as sardines into a powder. In the case of feed for farmed fish and shellfish suitable for carnivorous fish, such fishmeal is included at an average of 55% to increase the weight of the fish. However, sardines, which have been caught in large quantities in coastal waters and have supported Japan's marine aquaculture industry as raw materials for fishmeal and fish oil, have seen a drastic decline in catches in recent years, forcing Japan to rely on imports from South American countries such as Peru and Chile for the majority of its needs. Moreover, internationally, aquaculture has been increasingly popular in countries such as Northern Europe, China, Southeast Asia, and North America in recent years, and as a result, fishmeal and fish oil, which are the main raw materials for compound feed for aquaculture, are in short supply worldwide.

[0005] Given this situation, there is a need to develop new types of feed for farmed fish and shellfish that move away from conventional feeds that rely on fishmeal and fish oil. As alternative ingredients to fishmeal, plant-based proteins such as soybean meal and corn gluten meal, and animal-based proteins such as chicken meal are being used.

[0006] For example, Patent Document 2 (Japanese Patent Publication No. 2019-187405) proposes a fish and shellfish aquaculture feed that, in light of the soaring prices of raw materials such as seaweed, fish meal, and grains, and the rising trend in the price of compound feed for abalone, contains brown algae and brown algae product residues mixed with rice bran, cultured with Aspergillus oryzae, and also includes secretions produced during Aspergillus oryzae culture.

[0007] Furthermore, Patent Document 3 (Japanese Unexamined Patent Publication No. 5-304897) proposes a feed for marine aquaculture fish containing at least sake lees and live bait. This feed is readily consumed by marine aquaculture fish, which have specific dietary and texture requirements, is inexpensive, exhibits desirable protein efficiency, and exhibits even more desirable protein efficiency when formed into pellets. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2021-10862 [Patent Document 2] Japanese Patent Publication No. 2019-187405 [Patent Document 3] Japanese Patent Application Publication No. 5-304897 [Overview of the project] [Problems that the invention aims to solve]

[0009] Patent Document 1 discloses a feed for farmed fish that improves the taste of farmed fish, which optionally includes rice bran and sake lees. However, the improvement in taste in Patent Document 1 is achieved by increasing the fat content of the edible portion, and for this purpose, one or two to five of soy sauce oil, beer lees, small sweetfish, dace, and Biwa trout scraps are used, with the total percentage of these being 5% to 70%, and rice bran and sake lees are merely used as ingredients in the blend.

[0010] Furthermore, Patent Document 2 proposes adding rice bran to seaweed residue that is disposed of as industrial waste, mixing it, and inoculating it with koji mold to cultivate it, thereby creating a feed for aquaculture of fish and shellfish such as abalone. However, it has not been considered whether sufficient feed intake can be secured in farmed fish, and no consideration has been given to improving the taste of farmed fish.

[0011] Furthermore, Patent Document 3 proposes a feed for marine aquaculture fish containing sake lees and live bait, but the live bait and sake lees are simply mixed by conventionally known methods. For this reason, when obtaining pelletized feed for marine aquaculture fish, it is necessary to use frozen or semi-frozen live bait and sake lees for molding, making storage and feeding at room temperature difficult.

[0012] Therefore, one of the objectives of the present invention is to provide a feed for farmed fish and shellfish that can be stored and fed at room temperature while using alcohol fermentation residues such as sake lees, and that can improve the taste of farmed fish and shellfish, as well as fermentation materials used in its production, and a method for producing the feed for farmed fish and shellfish.

[0013] Another objective of this invention is to provide a feed for farmed fish and shellfish that, while using plant-based protein sources, has a feed effect on farmed fish and shellfish that is comparable to that of feed for farmed fish and shellfish that uses animal-based protein sources such as fishmeal, as well as fermentation materials used in its production and a method for producing such a feed for farmed fish and shellfish. In other words, to provide a feed for farmed fish and shellfish that uses only plant-based raw materials but has a high protein content, as well as fermentation materials used in its production and a method for producing such a feed for farmed fish and shellfish.

[0014] Furthermore, another objective is to provide a feed for farmed fish and shellfish that can maintain clear water quality in fish farms and further improve the growth rate of farmed fish, as well as fermentation materials used in its production, and a method for producing the feed for farmed fish and shellfish.

[0015] Furthermore, another objective of this invention is to provide a feed for farmed fish and shellfish that uses only plant-based raw materials, yet is readily consumed by the farmed fish and shellfish and promotes their growth, as well as fermentation materials used in its production, and a method for producing the feed for farmed fish and shellfish. [Means for solving the problem]

[0016] In order to solve at least one of the above problems, the inventors focused on the components contained in alcohol fermentation residues such as sake lees and revised the present invention. Furthermore, in order to solve at least one of the above problems, the inventors focused on the content of free amino acids in feed for farmed fish and shellfish and completed the present invention.

[0017] In other words, the present invention provides a fermentation material for producing feed for farmed fish and shellfish used in aquaculture, which contains a lactic acid bacteria fermentation product obtained by fermenting an alcohol fermentation residue with lactic acid bacteria. Such a fermentation material may further contain an alcohol fermentation product. The fermentation material containing the lactic acid bacteria fermentation product obtained by fermenting an alcohol fermentation residue with lactic acid bacteria and the fermentation material containing the alcohol fermentation product can be stored separately and used in combination or mixed together. These fermentation materials contain microorganisms such as yeast, lactic acid bacteria, or koji mold, and can be used as raw materials for fermenting the fermentation substrate described later.

[0018] Furthermore, the present invention provides a feed for farmed fish and shellfish manufactured using the fermentation material. Specifically, the present invention provides a feed for farmed fish and shellfish used in the cultivation of fish and shellfish, which contains a lactic acid bacteria fermentation product obtained by fermenting alcohol fermentation residue with lactic acid bacteria. Since such aquaculture feed for fish and shellfish can solve at least one of the problems of the present invention if it contains components based on alcohol fermentation residue, which is a raw material for fermenting the substrate, or lactic acid fermentation products obtained by fermenting the alcohol fermentation residue with lactic acid bacteria, it is not possible or practical to directly specify it by its structure or properties, so it is appropriate to define it as containing "lactic acid fermentation products obtained by fermenting alcohol fermentation residue with lactic acid bacteria."

[0019] The present invention also provides a feed for farmed fish and shellfish in which the alcohol fermentation residue is sake lees, and a mixture of the lactic acid bacteria fermentation product and rice bran is fermented. That is, instead of using the alcohol fermentation residue such as sake lees as is as a fermentation material, the alcohol fermentation residue is fermented with lactic acid bacteria and used as a material for fermenting the fermentation substrate. By fermenting the substrate using a fermentation material obtained by fermenting the alcohol fermentation residue with lactic acid bacteria, the amino acid content, especially the free amino acid content, can be increased.

[0020] The feed for cultured fish and shellfish according to the present invention is produced by fermenting rice bran using a component (first fermentation material) obtained by fermenting sake lees with lactic acid bacteria. Since the components contained in the fermentation process change at any time, it is impossible or approximately impractical to directly specify the feed for cultured fish and shellfish as the final fermentation product based on its structure or characteristics (impossible / impractical situation). That is, it is more appropriate to define this feed for cultured fish and shellfish as "containing a lactic acid bacteria fermentation product obtained by fermenting sake lees with lactic acid bacteria, and fermenting a mixture of the lactic acid bacteria fermentation product and rice bran."

[0021] By fermenting a vegetable substrate containing vegetable protein using the lactic acid bacteria fermentation product of the alcohol fermentation residue, the content of free amino acids can be made 0.3% by mass or more, preferably 0.5% by mass or more, and particularly preferably 0.6% by mass or more in such feed for cultured fish and shellfish. Also, in the feed for cultured fish and shellfish of the present invention, it is also desirable to contain free methionine, and it is desirable that the content of free methionine is 0.1 g or more, particularly 0.2 g or more per 100 g of the feed. Also, it is desirable that the content of free glutamic acid is 40 mg or more, particularly 45 mg or more per 100 g of the feed. This is to optimize the growth rate of the aquaculture target.

[0022] Also, in the present invention, in order to solve at least any of the above problems, there is provided a feed for cultured fish and shellfish used in the culture of fish and shellfish, which is a feed for cultured fish and shellfish obtained by fermenting a vegetable substrate containing vegetable protein with a first fermentation material (for example, a first fermentation liquid) obtained by fermenting sake lees with lactic acid bacteria. Such feed for cultured fish and shellfish is produced by fermenting the vegetable substrate using the first fermentation liquid obtained by fermenting sake lees with lactic acid bacteria. Since the feed for cultured fish and shellfish produced by this method can solve the problems of the present invention by the fermentation substances derived from the raw materials (that is, sake lees and lactic acid bacteria), it is impossible to directly specify it based on its structure or characteristics, or it is approximately impractical.

[0023] In the present invention, in order to solve at least one of the above problems, a method for producing a feed for cultured fish and shellfish is provided. That is, a method for producing a feed for cultured fish and shellfish used in the culture of fish and shellfish, characterized in that a fermentation substrate containing protein and fat is fermented using a first fermentation liquid produced by subjecting sake lees to lactic acid fermentation. Also, the fermentation process of the plant substrate by the first fermentation liquid (first fermentation material) and the second fermentation liquid (second fermentation material) described later is preferably carried out by anaerobic fermentation.

[0024] In the feed for cultured fish and shellfish of the present invention, additives may be optionally blended. Examples of such additives include vitamins such as vitamin A, B1, B2, B6, B12, C, D3, E, K3, choline, pantothenic acid, biotin, inositol nicotinate, folic acid, minerals such as calcium, phosphorus, magnesium, iron, zinc, manganese, copper, cobalt, molybdenum, iodine, sulfur, organic or inorganic selenium, amino acids such as methionine, lysine, tryptophan, glutamic acid, glycine, alanine, enzymes such as protease, cellulase, amylase, pectinase, bile powder, garlic powder, seaweed powder, antibiotics, vaccines, insecticides, etc. In addition, fish meal, shrimp and crab meal, grains, oil cakes, silkworm feces, adhesives such as sodium alginate and guar gum may also be used. It is also convenient and preferable to use commercially available compound feeds that are appropriately mixed in advance.

[0025] The feed for cultured fish and shellfish according to the present invention can also be used in combination with other commercially available feeds for cultured fish and shellfish. In particular, in the case of feeds for cultured fish and shellfish produced using plant raw materials such as sake lees and rice bran, they can also be used in combination with commercially available feeds for cultured fish and shellfish produced using animal raw materials. Especially when the feed for cultured fish and shellfish according to the present invention is produced solely using plant raw materials, the blending ratio with commercially available feeds for cultured fish and shellfish using animal raw materials can be arbitrarily adjusted, and as a result, the taste of cultured fish can be improved and the growth can be accurately managed.

Effects of the Invention

[0026] The present invention provides a feed for farmed fish and shellfish that eliminates the need to use animal protein sources such as fish meal, and also improves the growth rate of farmed fish, thereby realizing a feed for farmed fish and shellfish and a method for producing the same. Furthermore, by using plant-based protein sources, it is possible to maintain clear water quality in fish farms and to provide a feed for farmed fish and shellfish, as well as a method for producing the same, which can further improve the growth rate of farmed fish.

[0027] In particular, when the first fermentation liquid is produced using sake lees and rice bran is used as the fermentation substrate, sake lees and rice bran, which have previously been treated as waste, can be effectively utilized, promoting fish growth, enabling growth with less protein than conventional feeds, improving digestion and absorption efficiency, and reducing waste. This can also contribute to water quality preservation in aquaculture facilities. Furthermore, fish feed that can be produced domestically without relying on imports will lead to price stability and promote sustainable development in the aquaculture industry.

[0028] Furthermore, raising fish using plant-based protein instead of animal protein has a lower environmental impact and is desirable for protecting global protein resources. This is because the production of animal protein requires raw materials such as grains for feed and fishmeal and fish oil for the fish, which can lead to overexploitation of fishery resources. On the other hand, plant-based protein is derived from plants, and using these raw materials in fish feed reduces the environmental impact compared to using animal protein. Plant-based protein can promote more sustainable aquaculture methods and enable the efficient use of food resources, thereby contributing to the sustainability of the planet.

[0029] Globally, aquaculture using plant-based proteins is attracting attention, and in particular, large-scale aquaculture operators and international food companies are working to promote the use of plant-based proteins from the perspective of environmental considerations and sustainability. This is expected to reduce the environmental impact of food production, enable the sustainable use of food resources, and contribute to the protection of the global environment.

[0030] By reusing alcohol fermentation residues such as sake lees and plant-based substrates such as rice bran, waste disposal costs can be reduced, contributing to sustainable development in the region. Furthermore, branding locally farmed fish is expected to contribute to the revitalization of the local economy and the development of the tourism industry. Therefore, this invention has the potential to be implemented throughout Japan, and if similar initiatives are carried out in other regions, it is expected to yield significant results in both regional economic development and environmental protection. [Brief explanation of the drawing]

[0031] [Figure 1] Manufacturing process diagram for farmed fish and shellfish feed shown in the first embodiment [Figure 2] Manufacturing process diagram for farmed fish and shellfish feed shown in the second embodiment [Figure 3] Component analysis results of Example 1 [Figure 4] Amino acid analysis results of Example 1 [Figure 5] Free amino acid analysis results for Example 1 [Figure 6] Raw material names and composition of the base feed in Example 2 [Figure 7] Changes in feed intake and average fish weight for each group in Example 2 [Figure 8] Weight gain rate and feed efficiency of each group in Example 3 [Figure 9] Component analysis results of Example 3 [Figure 10] Free amino acid analysis results for Example 3 [Modes for carrying out the invention]

[0032] The following describes in detail, with reference to the drawings, the feed for farmed fish and shellfish according to this embodiment and the method for producing it. First Embodiment

[0033] The aquaculture feed 60 according to this embodiment uses a plant-based substrate containing plant protein and plant oil as the fermentation substrate 50 containing protein and oil, and in particular uses rice bran. As shown in Figure 1, the rice bran, which is the fermentation substrate 50, is fermented with a first fermentation liquid 10, which is a first fermentation material obtained by fermenting sake lees, which is the alcohol fermentation residue 30, with lactic acid bacteria.

[0034] [First fermentation liquid: 10] The first fermentation liquid 10 is a fermentation liquid produced by lactic acid fermentation, and can be produced by fermenting alcohol fermentation residues 30 such as sake lees, beer lees, and wine lees with lactic acid bacteria.

[0035] It is desirable that the lactic acid bacteria used be cultured in advance, and various culture media can be used for the culture, such as milk media or media containing milk components, or semi-synthetic media that do not contain these. In particular, in this embodiment, the culture medium (carbohydrate-containing component) can be an animal-derived carbohydrate-containing component (culture medium) such as milk, or a plant-derived carbohydrate-containing component (culture medium) such as soy milk. In particular, when the feed 60 for farmed fish and shellfish is manufactured using a plant-based substrate, it is desirable to use a plant-derived carbohydrate-containing component (culture medium) such as soy milk.

[0036] Such lactic acid bacteria can be cultured according to the standard methods for culturing lactic acid bacteria. For example, the culture temperature can be 30-37°C and the pH can be in the range of 3.5-4.0. This is to enhance the activity of the lactic acid bacteria and suppress the growth of microorganisms other than lactic acid bacteria.

[0037] Furthermore, additives can be used in the production of the first fermentation liquid 10, primarily for the purpose of suppressing the growth of microorganisms other than lactic acid bacteria. For example, sodium azide can be added to prevent the growth of aerobic bacteria (miscellaneous bacteria), cycloheximide can be added to prevent the growth of fungi such as mold, and organic acids can be added to suppress the growth of miscellaneous bacteria.

[0038] The lactic acid bacteria used to produce the first fermentation liquid 10 can be microorganisms belonging to the genera Lactobacillus, Streptococcus, Pediococcus, Leuconostoc, Lacticaseibacillus, Lactiplantibacillus, and Bifidobacterium. These microorganisms can be used individually or in combination of two or more lactic acid bacteria as appropriate. In particular, in this embodiment, lactic acid bacteria of the genus Lactobacillus are used to ensure food safety. Then, by culturing lactic acid bacteria in soy milk, a yogurt-like culture component 11 can be produced. This yogurt-like culture component 11 is added to the alcohol fermentation residue 30 to carry out the first stage of fermentation.

[0039] As mentioned above, the alcohol fermentation residue 30 to be fermented can be any residue from alcohol fermentation, such as sake lees, beer lees, or wine lees, but sake lees are particularly desirable. Sake lees are rich in amino acids and glucose produced from rice fermentation, which are the source of umami, and can increase the intake of farmed fish and shellfish. They also contain peptides, dietary fiber, oligosaccharides, B vitamins, adenosine, and resistant protein, making them suitable for the growth of farmed fish and shellfish. Furthermore, the koji mold contained in sake lees produces many enzymes, including proteases that break down proteins into amino acids, amylases that break down starch into sugars, and lipases that break down lipids. Therefore, by using the first fermentation liquid 10 made from sake lees, it is possible to produce a feed 60 for farmed fish and shellfish that contains many amino acids.

[0040] Furthermore, in this first stage of fermentation, the fermentation rate in sake lees can be accelerated by using a yogurt-like culture component 11 obtained by culturing lactic acid bacteria in soy milk. However, if a sufficient amount of lactic acid bacteria can be secured, the cultivation in soy milk can be omitted, and the alcohol fermentation residue 30 can be fermented using lactic acid bacteria alone.

[0041] During the production of the first fermentation liquid 10 as described above, essential amino acids such as peptides are generated. These essential amino acids are the basic building blocks of protein synthesis and are necessary for the synthesis of many proteins in the bodies of farmed fish and shellfish, as well as for growth and tissue repair. Therefore, the use of the first fermentation liquid 10, which contains sufficient essential amino acids, is suitable for the production of feed 60 for farmed fish and shellfish.

[0042] The first fermentation liquid 10 is preferably adjusted in pH and temperature from the viewpoint of inhibiting the activity of lactic acid bacteria and the growth of unwanted bacteria, and is particularly preferably adjusted to an acidic pH of 3.5 to 4.0. Therefore, it is desirable that the first fermentation liquid 10 contains a pH adjuster 40. As such a pH adjuster 40, organic acids such as citric acid, malic acid, tartaric acid, succinic acid, lactic acid, acetic acid, maleic acid, gluconic acid, aspartic acid, adipic acid, glutamic acid, and fumaric acid, or their salts, inorganic acids such as hydrochloric acid, nitric acid, boric acid, carbonic acid, and phosphoric acid, and inorganic bases such as sodium hydroxide can be used. In particular, considering that it is a feed for farmed fish and shellfish, inorganic iron acids such as ferrous sulfate, ferric nitrate, ferric phosphate, ferric chloride, and ferric bromide, and organic iron acids such as ferric acetate, ferric oxalate, ferric citrate, and ferric lactate are preferred. These can be used individually or as a mixture of two or more.

[0043] By adjusting the pH of the first fermentation liquid 10 using the pH adjusting agent 40, the activity of lactic acid bacteria can be enhanced while suppressing the growth of unwanted bacteria during fermentation. In particular, when using organic iron, iron is involved in cell division and DNA synthesis and is involved in the healthy growth of organisms, so sufficient intake of iron by farmed fish and shellfish can improve their growth rate. Furthermore, iron is also important for improving immunity, and can increase the resistance to disease in farmed fish and shellfish. Therefore, by incorporating organic iron, the activity of lactic acid bacteria in the first fermentation liquid 10 can be enhanced, and it can contribute to the growth and nutritional support of farmed fish and shellfish.

[0044] [Fermentation substrate: 50] Using the first fermentation liquid 10 produced by fermenting each of the above, a fermentation substrate 50 containing protein and oil is fermented. This fermentation substrate 50 is used as a protein source in feed 60 for farmed fish and shellfish, and in this embodiment, by fermenting the fermentation substrate 50 with the first fermentation liquid 10, components necessary for the growth of farmed fish and shellfish, such as free amino acids, are produced.

[0045] In this embodiment, rice bran, a plant-based substrate, is used as the fermentation substrate 50. However, other plant-based substrates containing plant-based proteins may also be used, such as peanuts, soybeans, or soybean residue. Furthermore, the fermentation substrate 50 is not necessarily limited to plant-based substrates; it may also be an animal-based raw material obtained by adding oils and fats such as fish oil or vegetable oil to an animal-based protein raw material such as fish meal. Moreover, these fermentation substrates 50, whether animal-based or plant-based, can be used in any combination in any proportion. Therefore, for example, plant-based substrates alone can be combined, animal-based raw materials alone can be combined, or plant-based substrates and animal-based raw materials can be combined.

[0046] The fermentation substrate 50 is preferably a plant-based substrate, especially rice bran, considering the ease and reliability of material availability and manufacturing costs. Rice bran contains a large amount of gamma-oryzanol, and when this gamma-oryzanol is administered to farmed fish and shellfish, lipids and carbohydrates in the feed are effectively taken up by somatic cells and used for energy production, resulting in an increase in the protein content in the muscles. Furthermore, the accumulation of high-density proteins leads to an increase in body weight. In particular, since fish absorb and accumulate gamma-oryzanol more actively than mammals, using rice bran promotes the efficient metabolism of lipids and carbohydrates contained in the feed 60 for farmed fish and shellfish, and increases the efficiency of converting the feed into the fish's body.

[0047] However, since many farmed fish species are carnivorous, and carnivorous fish species generally tend to produce more energy from amino acids than from carbohydrates, animal-based raw materials such as fishmeal may be added to increase the protein and amino acid content. When the feed for farmed fish and shellfish is 60% plant-based, it is desirable that the amount of such animal-based raw materials added be 50% by mass or less, especially 30% by mass or less, and even more preferably 10% by mass or less of the fermentation substrate 50.

[0048] In particular, feed 60 for farmed fish and shellfish made from plant-based materials is suitable for land-based aquaculture (inland water aquaculture). That is, land-based aquaculture is an advantageous method of raising fish and shellfish because it has fewer space limitations than marine aquaculture and is less affected by weather and natural disasters by using indoor facilities. However, in land-based aquaculture, the environment of the fish pens must always be kept in an optimal state in order to efficiently cultivate aquatic organisms in a limited space. For example, the amount of water circulated and the amount of feed given in the fish pens must be appropriately managed to maintain a sufficient oxygen concentration and to suppress the rise in ammonia concentration due to waste products.

[0049] In this regard, when plant-based feed 60 for farmed fish and shellfish is fed, the growing environment (e.g., the fish farm pond) for farmed fish and shellfish can be kept more hygienic compared to when animal-based feed 60 is fed. This is because the composition of excrement differs due to the difference in the components of the ingested feed, and the amount of excrement is also reduced, thus minimizing water pollution in the aquaculture facility (i.e., the fish pens).

[0050] [Fermentation process] In the fermentation of the above-mentioned fermentation substrate 50 (rice bran in this embodiment) using the first fermentation liquid 10, the lactic acid bacteria and yeast contained in the first fermentation liquid 10 metabolize carbohydrates to produce acids and alcohols. During this process, proteins are broken down and free amino acids are produced. In particular, in lactic acid fermentation and alcoholic fermentation, proteases are activated and break down proteins to produce free amino acids. It is desirable to carry out this fermentation process using anaerobic fermentation. By carrying out anaerobic fermentation, the production of essential amino acids such as peptides can be promoted. In this fermentation process, once fermentation begins, the temperature rises to around 50°C, the color changes to brown, and gradually becomes darker. When it approaches dark brown, the color is checked and the process is completed. The change to dark brown is due to the Maillard reaction of amino acids, and the temperature gradually decreases and the fermentation settles down.

[0051] In this fermentation process, it is desirable to adjust the pH in order to activate beneficial bacteria such as lactic acid bacteria and to suppress the growth of unwanted bacteria. For this purpose, it is desirable to include the pH adjuster 40, and in particular, it is desirable to add an organic iron acid such as iron citrate.

[0052] Furthermore, the first fermentation liquid 10, obtained by lactic acid fermentation of sake lees (the alcohol fermentation residue 30), is fluid and difficult to mold into solid shapes such as pellets as is. Therefore, by adding this first fermentation liquid 10 to rice bran and performing a second fermentation, it can be made moldable enough to be formed into pellets or the like. Consequently, the aquaculture feed 60 produced in this fermentation process can maintain its shape even at room temperature and can be molded into granular or solid shapes, for example.

[0053] According to the above embodiment of feed 60 for farmed fish and shellfish, even when using plant-based materials, it is possible to obtain feed 60 for farmed fish and shellfish that contains a large amount of free amino acids. When farmed fish and shellfish ingest such free amino acids, they provide a growth-promoting effect that supports protein synthesis and promotes weight gain and overall growth, an immunity-enhancing effect that strengthens immune function and increases resistance to disease due to specific free amino acids, an effect of increasing feed intake by increasing the appetite of fish due to the inclusion of umami components such as glutamic acid, and an effect of improving feed conversion efficiency by containing a large amount of free amino acids, which allows for greater growth with the same amount of feed. Second Embodiment

[0054] In this embodiment, as shown in Figure 2, in addition to the first fermentation liquid 10 in the first embodiment, a second fermentation liquid 20 containing alcohol is used to ferment the fermentation substrate 50 made of rice bran. [Second fermentation liquid: 20] The second fermentation liquid (second fermentation material) 20 is produced by generating alcohol with yeast and sugars, and can be manufactured as an alcoholic fermentation product. Furthermore, if the purpose is to encourage vigorous feeding by farmed fish, sugar components may be left in the alcoholic fermentation product. These sugar components may be present or blended in such a way that the sugar content of the manufactured feed for farmed fish and shellfish is 1.5% or more, particularly 2.0% or more. The second fermentation liquid 20 can optionally be formed by blending the yogurt-like culture component 11 and the pH adjuster 40. In the production of this second fermentation liquid 20, fermentation is carried out until the pH reaches 3.5 or higher, and up to 4.0, due to the acids and carbon dioxide produced during the alcoholic fermentation process. This is because a pH below 3.5 may inhibit the activity of lactic acid bacteria, while a pH above 4.0 may lead to the proliferation of unwanted bacteria.

[0055] The yeast used in the production of the second fermentation liquid 20 can be any yeast capable of alcoholic fermentation without any particular restrictions. For example, yeasts such as those belonging to the genera Saccharomyces, Candida, Torulopsis, Zygosaccharomyces, Schizosaccharomyces, Pichia, Yarrowia, Hansenula, Kluyveromyces, Debaryomyces, Geotrichum, Wickerhamia, and Fellomyces can be used.

[0056] The second fermentation liquid 20 can be mixed with the first fermentation liquid 10 before being added to the fermentation substrate 50, or it can be added at the same time as the first fermentation liquid 10, or at a different time (with a time delay) than the timing of adding the first fermentation liquid 10. If the timing of adding the first fermentation liquid 10 and the second fermentation liquid 20 is different, the timing of mixing can be appropriately adjusted according to the temperature, humidity, and the amount of fermentation substrate 50. [Examples]

[0057] In the following, analytical tests were conducted on the components and amino acids of the feed for farmed fish and shellfish manufactured according to the above embodiment. The feed for farmed fish and shellfish evaluated in this example was manufactured by the following method.

[0058] [Manufacturing of feed for farmed fish and shellfish] 2000cc of soy milk was inoculated with lactic acid bacteria [LaalactObadllus curvatus NBRC 107129 strain] and fermented at a temperature of 41°C for 10 hours to create plant-based yogurt. 2000cc of this plant-based yogurt and 15 liters of iron citrate (pH 4, iron content 1 mg / L) were added to 15 kg of sake lees and fermented for 24 hours to produce the first fermented liquid. 500cc of the aforementioned plant-based yogurt, 400g of brown sugar, and 1500cc of water were mixed together and fermented for approximately 5 days until the pH reached 3.5-4.0 to produce a second fermented liquid. Then, 10 L of iron citrate solution was added to a substrate made from a mixture of the first and second fermented liquids, 150 kg of rice bran, and 15 kg of peanuts, and water was added to achieve a moisture content of approximately 40%, and the mixture was stirred. This was then subjected to anaerobic fermentation to produce feed for farmed fish and shellfish. This feed for farmed fish and shellfish was then formed into granules.

[0059] "Component analysis" The above-mentioned feed for farmed fish and shellfish was subjected to a content analysis at the Yamagata Prefectural Physicochemical Analysis Center. The results are shown in Figure 3. The test results showed that, as this was a feed for farmed fish and shellfish using a plant-based substrate, the crude protein content was 24%. This is significantly lower than the approximately 60% found in feeds for farmed fish and shellfish using animal-based ingredients such as fishmeal.

[0060] [Amino Acid Analysis] The amino acid content ratio of the first fermentation liquid using sake lees was confirmed. Specifically, a comparative feed was prepared by not using the first fermentation liquid in the above-mentioned method for producing feed for farmed fish and shellfish, but instead adding Fish Solible (manufactured by Crea Japan Co., Ltd., product name "Fish Amino 7") at a rate of 1 L per 150 kg of feed before addition. The types and content ratios of amino acids in this comparative feed and the feed for farmed fish and shellfish produced using the first fermentation liquid were compared. The types and content ratios of amino acids contained in the comparative feed and the feed for farmed fish and shellfish were analyzed by automated amino acid analysis at the Japan Food Research Laboratories. The results are shown in Table 1 and Figure 4 below, with the comparative feed without the first fermentation liquid designated as Experimental Example 1, and the feed for farmed fish and shellfish using the first fermentation liquid obtained by lactic acid fermentation of sake lees designated as Experimental Example 2.

[0061] [Table 1]

[0062] From these experimental results, it was confirmed that the feed for farmed fish and shellfish according to this embodiment contains many essential amino acids, and in particular, 2.43% of glutamic acid, which is an umami component. Furthermore, by comparing the feed with a comparative feed that did not use the first fermentation liquid made from sake lees, it was confirmed that using the first fermentation liquid made from sake lees increased the content of all amino acids, and in particular, the content of prophosphate, a collagen component, and glutamic acid, an umami component, increased.

[0063] [Free amino acid analysis] The free amino acid content of the first fermentation liquid using sake lees was confirmed. Specifically, a comparative feed was prepared by not using the first fermentation liquid in the above-mentioned method for producing feed for farmed fish and shellfish, but instead adding Fish Solible (manufactured by Crea Japan Co., Ltd., product name "Fish Amino 7") at a rate of 1 L per 150 kg of feed before addition. The types and content of free amino acids contained in this comparative feed and the feed for farmed fish and shellfish produced using the first fermentation liquid were compared. The types and content of free amino acids contained in the comparative feed and the feed for farmed fish and shellfish were analyzed at the Japan Food Research Laboratories using an automated amino acid analysis method. The results are shown in Table 2 and Figure 5 below, with the comparative feed without the first fermentation liquid designated as Experimental Example 3, and the feed for farmed fish and shellfish using the first fermentation liquid containing sake lees designated as Experimental Example 4.

[0064] [Table 2]

[0065] From these experimental results, it was confirmed that the feed for farmed fish and shellfish according to this embodiment contains all 16 types of free amino acids, with a content of 944 mg per 100 g. Furthermore, by comparing the feed with a comparative feed that did not use the first fermentation liquid made from sake lees, it was confirmed that using the first fermentation liquid made from sake lees increased the content of free amino acids, and in particular, increased the content of prophosphate, a collagen component, and glutamic acid, an umami component. [Examples]

[0066] In the following, we evaluated the feed for farmed fish and shellfish (hereinafter referred to as "sake lees feed") produced in Experimental Example 1 above by actually farming fish.

[0067] [Test Method] 1. Setting of test animals and test plots (1) Test fish From 1,000 juvenile cherry salmon (yamame) whose eggs were collected on September 20, 2023, and which hatched from November 17, they were pre-raised in a test tank for 18 days using commercially available salmon and trout feed. From these, 120 individuals with a fish weight of 0.30-0.44 g / fish were selected for testing, excluding deformed and stunted individuals. (2) Setting of test plots Six experimental groups were established: one group fed a base feed without sake lees feed (composition shown in Figure 6), and two groups fed test feeds containing 20% ​​and 30% sake lees feed by substituting it for the base feed. Repeat groups were also set up for each of the six groups. Twenty test fish were divided into each of these six groups to ensure a nearly even weight distribution, and the experiments were conducted. In the "Growth Experiment of Cultured Aquatic Animals," several experimental groups were established, ranging from a group using a normal amount of sake lees feed to a group using the largest possible amount of sake lees feed, as well as a negative control group. Therefore, a group with a sake lees feed content of 20% (hereinafter referred to as the 20% sake lees feed group), which met the protein requirements of juvenile cherry salmon (34-43%), was designated as the normal amount of sake lees feed, and a group with a sake lees feed content of 30% (hereinafter referred to as the 30% sake lees feed group) was designated as the group using the largest possible amount of sake lees feed.

[0068] 2. Feed for use (1) Basic feed A compound feed for salmon and trout fry (Figure 6) was used. The composition of this compound feed is 46% protein, 4% fat, 7% fiber, 16% ash, 1.6% calcium, and 1.2% phosphorus (according to the composition table of salmon and trout feed used in trout seedling production at the National Institute of Inland Fisheries). (2) Sake lees feed The fish farming feed mixed with sake lees prepared in Example 1 was used. (3) Feeding The amount of food given was based on the amount of food consumed when the fish were full, and was set at 3.5% of the total fish weight in each section. Total fish weight was measured at the start of the experiment and every 7 days thereafter, and the amount of food given for the 7 days until the next fish weight measurement was the same as the amount measured at the previous measurement. Feeding was done three times a day.

[0069] 3. Feeding period for the feed provided. The average fish weight in the control group tripled, so the study period was extended to six weeks.

[0070] 4. Rearing conditions (1) Aquarium Each section was a tank with a capacity of 6 liters (35 cm high x 17 cm wide x 10 cm deep). (2) Water supply and rearing environment Groundwater was used as the water source, and the water temperature remained between 12.2 and 13.0°C during the test period. The water flow rate was 108 liters / hour, and the rotation speed was 18 times / hour.

[0071] 5. Observation items and results A. General symptoms 1) Feeding status Feeding was active in all sections, and no differences were observed between sections. 2) Abnormal behavior No abnormal behavior was observed in any of the districts. 3) Abnormalities in body color and body shape One individual with poor growth was observed in the group containing 20% ​​sake lees feed, so a necropsy was performed after the end of the experiment. (i) Feed amount, body weight, and mortality rate 1) Amount of feed to be given Feed amounts were calculated every 7 days from the start of the experiment, and the total amount was tallied at the end of the experiment (Figure 7). 2) Weight The average fish weight was measured seven times in total: at the start of the experiment, every seven days thereafter, and at the end of the experiment (Figure 7). 3) Death No deaths were reported in any district during the testing period. (c) Weight gain, feed efficiency, and mortality rate 1) Weight gain rate (Total weight at the end - Total weight at the start + Total weight of dead fish) × 100 / Total weight at the start The weight gain rate for each section was calculated using the "weight" calculation formula (Figure 8). 2) Feed efficiency "(Total weight at the end - Total weight at the start + Total weight of dead fish) × 100 / Dry weight equivalent The feed efficiency for each section was calculated using the formula for "total feed amount" (Figure 8). 3) Mortality rate Since no deaths were reported in any district during the testing period, this data has been omitted. E. Autopsy In the group containing 20% ​​sake lees feed, one individual exhibited poor growth, and therefore a necropsy was performed at the end of the experiment. The autopsy revealed no abnormalities on the body surface or parasites, and no abnormalities were found in the internal organs such as the gills, liver, spleen, or kidneys. However, a deformity was observed from the lower jaw to below the gill fins. In trout species, it is normal for differences in growth to occur due to the development of strong and weak individuals within the same group, leading to differences in feeding, as well as due to genetic predispositions, and these individual differences are particularly pronounced during the rapid growth period of juvenile fish. Furthermore, no abnormalities due to any disease were found during the autopsy, and no abnormalities were observed in other individuals kept in the same tank. Given that the deformity was observed from the lower jaw to below the gill fins, it was considered that the cause was individual variation or malformation, and that the sake lees feed was unlikely to be the cause.

[0072] 〔evaluation〕 In the group that used 30% sake lees feed, the average fish weight, weight gain rate, and feed efficiency at the end of the experiment were lower than in the control group. However, in the group that used the regular amount of sake lees feed, the values ​​were comparable to the control group. Furthermore, no weight loss was observed in any group during the experiment, and there were no deaths or abnormalities found in pathological examinations. Therefore, we believe that the safety of sake lees feed was confirmed in this study. [Examples]

[0073] In the following, the substrate for farmed fish and shellfish feed produced in Example 1 was changed from a mixture of 150 kg of rice bran and 15 kg of peanuts to a mixture of 45 kg of rice bran and 55 kg of soybean pulp, and methionine was added along with the first and second fermentation liquids. The content of methionine in this feed was tested at the Yamagata Prefectural Chemical Analysis Center, a general incorporated association, in the same manner as in Example 1. The results are shown in Figure 9. The amount of methionine added in this example was 0.4% by mass of the farmed fish and shellfish feed produced. Furthermore, the results of the analysis of the amino acid content ratio in the aquaculture feed (produced using the first fermentation liquid) manufactured in Example 2 are presented as Experimental Example 5, in comparison with Experimental Example 3, and are shown in Table 3 and Figure 10 below.

[0074] [Table 3] These test results confirmed that a feed for farmed fish and shellfish with a crude protein content exceeding 30% by mass can be produced by fermenting a base material consisting of rice bran and soybean pulp with a first fermentation liquid obtained by lactic acid fermentation of sake lees and a second fermentation liquid which is an alcoholic fermentation product. Furthermore, it was confirmed that the feed contains 280 mg of free methionine per 100 g, which is effective in promoting the growth of farmed fish that consume it. [Industrial applicability]

[0075] The feed for farmed fish and shellfish of the present invention can be used not only as feed for farming fish and shellfish, but also as feed for ornamental fish and even as fishing bait. In addition, it can be used as feed for livestock and pets. [Explanation of symbols]

[0076] 10. First fermentation liquid 11 Culture components 20 Second fermentation liquid 30 Alcohol fermentation residue 40 pH adjusters 50 Fermentation substrate 60 Feed for farmed fish and shellfish

Claims

1. A fermentation material for producing feed for farmed fish and shellfish used in aquaculture, A fermentation material for the production of feed for farmed fish and shellfish, containing a lactic acid fermentation product obtained by fermenting alcohol fermentation residue with lactic acid bacteria.

2. The fermentation material for producing feed for farmed fish and shellfish according to claim 1, further comprising an alcoholic fermentation product.

3. Feed for farmed fish and shellfish used in the cultivation of fish and shellfish, A feed for farmed fish and shellfish containing a lactic acid fermentation product obtained by fermenting alcohol fermentation residue with lactic acid bacteria.

4. The feed for farmed fish and shellfish according to claim 3, wherein the alcohol fermentation residue is sake lees, and the feed is obtained by fermenting a mixture of the lactic acid bacteria fermentation product and rice bran.

5. The feed for farmed fish and shellfish according to claim 3, wherein the amino acid content is 12% by mass or more, and / or the free amino acid content is 600 mg or more per 100 g.

6. The feed for farmed fish and shellfish according to claim 3, wherein the crude protein content is 40% by mass or less.

7. The feed for farmed fish and shellfish according to claim 3, comprising free methionine.

8. The feed for farmed fish and shellfish according to claim 3, wherein the sugar content is 1.5% or more.

9. Feed for farmed fish and shellfish used in the cultivation of fish and shellfish, A feed for farmed fish and shellfish, characterized by fermenting a plant-based substrate containing plant protein with a first fermentation liquid obtained by fermenting alcohol fermentation residue with lactic acid bacteria.

10. A method for producing feed for farmed fish and shellfish used in the cultivation of fish and shellfish, A method for producing feed for farmed fish and shellfish, characterized by using a first fermentation liquid produced by fermenting alcohol fermentation residue with lactic acid bacteria to ferment a fermentation substrate containing protein and oil.

11. A method for producing feed for farmed fish and shellfish according to claim 9 or 10, further comprising using a second fermentation liquid consisting of an alcoholic fermented product to ferment a fermentation substrate containing protein and oil.

12. The method for producing feed for farmed fish and shellfish according to claim 9 or 10, wherein the alcohol fermentation residue is sake lees and the fermentation substrate is rice bran.

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