Formula feed, formula feed manufacturing method, and use

Abstract

Benthic organisms such as sea urchins, sea cucumbers, abalone, and shrimp have slower feeding behavior than fish, and therefore require feed that has high shape retention even in water. The present invention aims to provide a compound feed suitable for cultivating aquatic animals, particularly benthic organisms. The present invention provides a compound feed containing water-insoluble fine fibers, a method for producing the compound feed, and the use of the water-insoluble fine fibers in maintaining the shape of feed for aquatic animals.

Description

[Technical Field]

[0001] The present invention relates to a compound feed containing fiber, a method for producing a compound feed, and the use of fiber in a compound feed. [Background technology]

[0002] Feeds for cultivating marine benthic organisms such as sea urchins, sea cucumbers, abalone, shrimp, etc. are known. Examples include sea urchin farming feed in which seaweed and wheat flour are the main protein sources (see Patent Document 1), marine invertebrate feed in which alginic acid powder is used to solidify algae powder and food processing residues (see Patent Document 2), and aquatic animal feed consisting of dried gelatinized rice with powdered seaweed dispersed in it (see Patent Document 3).

[0003] There is a known invention relating to sea urchin livestock feed containing seaweed and sea urchin innards or crushed products thereof, and it has been disclosed that crushed seaweed and sea urchin gonads are solidified using agar (see Patent Document 4). Also known is a compound feed for abalone, characterized by being made into a paste by adding edible paste substances such as agar seaweed, agar powder, rice cake powder, and American flour (see Patent Document 5).

[0004] Also disclosed are feed additives containing carboxymethylated cellulose nanofibers for the purpose of imparting shape retention to feed (see Patent Documents 6 and 7). Furthermore, silkworm feed containing cellulose nanofibers is also known (see Patent Document 8). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-101401 [Patent Document 2] Japanese Patent Publication No. 2023-091558 [Patent Document 3] Japanese Patent Application Publication No. 2022-149294 [Patent Document 4] Japanese Patent Application Publication No. 2022-149294 [Patent Document 5] Japanese Patent Application Publication No. 11-046696 [Patent Document 6] Patent No. 7412902 [Patent Document 7] Patent No. 7245237 [Patent Document 8] Patent No. 7289482 Summary of the Invention [Problem to be solved by the invention]

[0006] Because benthic organisms such as sea urchins, sea cucumbers, abalone, and shrimp have slower feeding behavior than fish, feed for benthic organisms needs to have improved shape retention in water. Patent Documents 6 and 7 disclose feed additives containing water-soluble carboxymethylated cellulose nanofibers, but the examples disclosed in these documents are feed pellets containing only ground carboxymethylated pulp, and no other ingredients are blended into the feed pellets. Furthermore, these pellets are for ruminants, and it was unclear whether the feed additives disclosed in these documents could be used in feed for aquatic animals. [Means for solving the problem]

[0007] The present invention aims to provide a compound feed suitable for cultivating aquatic animals, particularly benthic organisms. That is, the present invention is a compound feed containing water-insoluble fiber. The fiber contained in the compound feed of the present invention may be fine fiber. Furthermore, the fibers contained in the compound feed of the present invention may be defibrated fine fibers.

[0008] In one embodiment of the present invention, the mixed feed is immersed in tap water at room temperature, shaken at an amplitude of 30 mm at a rotation speed of 200 rpm for 30 minutes, and then filtered through a mesh with 1 mm openings, such that the dry weight of the solids recovered is 30% or more of the dry weight of the mixed feed before shaking. The values ​​are rounded to one decimal place (the same applies hereinafter).

[0009] The fine fibers may be fine cellulose fibers and / or fine chitin fibers, or may be fine cellulose fibers that do not have a carboxymethyl group.

[0010] In one embodiment, the formulated feed contains the fine fibers in an amount of 0.1 to 80 wt % based on the dry weight of the feed. In another embodiment, the fine fibers may have a fiber diameter of 0.02 to 50 μm and a fiber length of 0.25 to 1.5 mm.

[0011] In one embodiment, the compound feed further comprises a cross-linking agent having multiple carboxyl groups, which may be citric acid.

[0012] Another aspect of the present invention provides a method for producing a compound feed, the method comprising the steps of applying a slurry containing feed ingredients to a substrate and drying the substrate to which the slurry has been applied.

[0013] In one embodiment, the slurry may contain water-insoluble fine fibers. In another embodiment, the slurry may contain 0.1 to 80 wt % of the fine fibers based on the dry weight. In another embodiment, the water content of the slurry may be 80 to 99 wt %. In one embodiment, the coating step may be a dip coating step.

[0014] Another aspect of the present invention provides a method for producing a compound feed, the method comprising the steps of: mixing a feed material containing a fiber having a hydroxyl group; and contacting the fiber with a cross-linking agent having multiple carboxyl groups. In one embodiment, the fiber may be a water-insoluble fine fiber, and the cross-linking agent may be citric acid.

[0015] The mixed feed produced by the manufacturing method of the present invention is immersed in tap water at room temperature, shaken at an amplitude of 30 mm at a rotation speed of 200 rpm for 30 minutes, and then filtered through a mesh with 1 mm openings, such that the dry weight of the solids recovered is 30% or more of the dry weight of the mixed feed before shaking. The values ​​are rounded to one decimal place (the same applies hereinafter).

[0016] Another aspect of the present invention provides a use of a water-insoluble fiber in maintaining the shape of a compound feed for aquatic animals. The fiber used may be a fine fiber.

[0017] Throughout the present invention, the compound feed may be a compound feed for sea urchin, sea cucumber, and / or abalone. [Effects of the Invention]

[0018] The compound feed of the present invention contains water-insoluble fiber and has high shape retention in water. Furthermore, a compound feed that further contains a cross-linking agent may have even higher shape retention than a compound feed with the same fiber content but without a cross-linking agent.

[0019] Another aspect of the present invention is a method for producing a compound feed comprising the steps of applying a slurry to a substrate and drying the substrate on which the slurry has been applied, which allows the production of a thin-layer compound feed. By forming the feed into a thin layer, the specific surface area increases, making it easier for benthic organisms to consume the feed. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram showing the residual rate of the compound feeds of the Examples and Comparative Examples when they were stirred in water. Error bars indicate standard deviation, and different letters in the figure indicate that a significant difference was observed at the p<0.01 level by Tukey's test after one-way analysis of variance (ANOVA). [Figure 2]1 shows the weight ratio of the recovered feed when the compound feeds of the Examples and Comparative Examples were stirred in water. Error bars indicate standard deviation, and different letters in the figure indicate that a significant difference was observed at the p<0.01 level by Tukey's test after one-way analysis of variance (ANOVA). [Figure 3] 1 is a diagram showing the recovered weight of compound feeds of Examples and Comparative Examples placed in sea urchin culture cages. Different letters in the figure indicate that a significant difference was found at the p<0.01 level by Tukey's test after one-way analysis of variance (ANOVA). [Figure 4] This is a photograph of the compound feed of the examples and comparative examples housed in sea urchin farming cages just before being collected. [Figure 5] 1 is a diagram showing the change over time in the gonad-body index of sea urchins in a rearing test of sea urchins using the formulated feed of the Example. The triple asterisks (***) in the figure indicate that a significant difference was observed at the p<0.001 level by t-test. [Figure 6] 1 is a graph showing the change in the average weight of sea urchins in a rearing test of sea urchins using the compound feed of the example. Error bars indicate standard deviation. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention provides a compound feed containing a water-insoluble fiber, and use of the water-insoluble fiber in maintaining the shape of feed for aquatic animals. Another aspect of the present invention provides a method for producing a compound feed, the method comprising the steps of applying a slurry to a substrate and drying the substrate to which the slurry has been applied. Yet another aspect of the present invention provides a compound feed containing a crosslinker having multiple carboxyl groups, and a method for producing the same. Hereinafter, the present invention will be described in detail based on embodiments of the invention, but the present invention should not be construed as being limited to the following embodiments.

[0022] The fiber used in the present invention is insoluble in water. It is believed that the inclusion of water-insoluble fiber in a compound feed improves shape retention in water. The fiber is used so that the compound feed retains its shape in water when contained in the compound feed. The fiber used in the present invention may be a water-insoluble fine fiber.

[0023] Shape retention means that the feed maintains its shape for a certain period of time after being placed in water without significant disintegration. The feed does not need to completely maintain the shape it had before being placed in water after being placed in water. Some disintegration of the feed shape is acceptable, as long as the shape is maintained to the extent that it can be consumed by the target animals.

[0024] The present invention provides a feed composition that can produce feed with high shape retention. In the present invention, shape retention refers to a physical property evaluated by the following test method. Specifically, a compound feed is immersed in tap water at room temperature (20±2°C), shaken at an amplitude of 30 mm and a rotation speed of 200 rpm for 30 minutes, and then filtered through a mesh with 1 mm openings. The dry weight of the recovered solids is evaluated as the ratio (hereinafter sometimes referred to as the residual ratio) to the dry weight of the compound feed before shaking.

[0025] Under the above conditions, the dry weight of the recovered solids of the feed composition of the present invention may be 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50% or more of the dry weight of the compound feed before shaking. The values ​​are rounded to one decimal place (the same applies hereinafter).

[0026] Furthermore, the shape retention of feed varies depending on molding conditions even for the same feed composition, and shape retention tends to be higher when molding is performed under pressure. As will be shown in the examples below, the feed composition of the present invention can provide feed with the above-mentioned high shape retention even when molded without applying any pressure other than the pressure due to its own weight.

[0027] The present invention provides a feed composition containing water-insoluble fiber. One embodiment of the feed composition of the present invention contains water-insoluble fiber such that when a compound feed of the feed composition is immersed in tap water at room temperature (20±2°C), shaken at an amplitude of 30 mm at a rotation speed of 200 rpm for 30 minutes, and then filtered through a mesh with 1 mm openings, the dry weight of the solids recovered is 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50% or more of the dry weight of the compound feed before shaking. The fiber may be fine fiber.

[0028] The fine fibers may be natural or synthetic fibers as long as they are insoluble in water. Natural fibers may be polysaccharides or proteins. Examples of fine natural fibers include fine cellulose fibers, fine chitin fibers, fine starch fibers, and / or fine collagen fibers. These may be fine fibrous cellulose, fine fibrous chitin, fine fibrous starch, fine fibrous collagen, etc.

[0029] Fine fibrous cellulose, also known as cellulose microfibers and / or cellulose nanofibers, is a fine cellulose fiber obtained by defibrating a cellulose-containing raw material such as wood. The cellulose fiber in the present invention is insoluble in water and therefore may be a non-carboxymethylated cellulose fiber, i.e., a cellulose fiber having no carboxymethyl groups.

[0030] Fine fibrous chitin, also known as chitin microfiber and / or chitin nanofiber, is a fine chitin fiber obtained by defibrating raw materials containing chitin, such as crab shells and shrimp shells.

[0031] Other examples of fine fibers include starch, collagen, fibroin, keratin, and the like that have been defibrated into fine fibers.

[0032] The fiber diameter and / or fiber length of the fine fibers used in the present invention are not limited, but may be, for example, 0.001 to 100 μm in diameter and 0.001 to 10 mm in length. An example of the fine fibers used in the present invention may be 0.02 to 50 μm in diameter and 0.25 to 1.5 mm in length.

[0033] In the present invention, compound feed refers to feed that is formed by blending multiple raw materials. The compound feed of the present invention can be produced as follows: Fine fibers and one or more raw materials other than fine fibers are mixed and molded. Water may be added to the mixed raw materials during mixing. If the moisture content of the molded feed is high, the molded feed is dried to obtain a compound feed with a moisture content below a certain value, for example, 20, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, or 5% by weight.

[0034] One embodiment of the compound feed of the present invention is a feed for aquaculture, and in particular, a feed for marine invertebrates. In one embodiment, it is a feed for marine benthic organisms. Specific examples of animals that can be fed with the feed of the present invention include echinoderms, mollusks, and crustaceans, and more specific examples include sea urchins, sea cucumbers, abalone, and benthic shrimp (such as kuruma prawns, Penaeus monodon, spiny lobsters, snow lobsters, and fan shrimp).

[0035] In one embodiment of the compound feed for benthic organisms such as sea urchins, sea cucumbers, and abalone, the compound feed may contain 0.1 to 80% by weight (by dry weight) of fine fibers. Since sea urchins, sea cucumbers, and abalone are thought to digest and absorb fibers such as cellulose, the fine fibers themselves can serve as nutrients for the animals, and therefore the compound feed may contain a high content of fine fibers.

[0036] On the other hand, because these benthic organisms prefer to feed on seaweed, the content of fine fibers may be reduced to a level that achieves the desired shape retention, and other raw materials such as seaweed may be increased. The compound feed of this embodiment contains 0.1 to 10 wt. % (by dry weight), 0.5 to 5 wt. % (by dry weight), or 1, 2, 3, or 4 wt. % (by dry weight) of fine fibers.

[0037] When the feed is for growing sea urchins, examples of the feed ingredients include seaweed powder, wheat flour, corn gluten meal, soybean meal, starch, fish oil, vegetable oil, salt, and pigments such as paprika powder. One embodiment of the sea urchin feed contains 0.1 to 10 parts by weight of fine fiber and 99.9 to 90 parts by weight of feed ingredients other than the fine fiber. The feed ingredients other than the fine fiber may contain 20 to 70 parts by weight of seaweed, 20 to 70 parts by weight of wheat flour, 1 to 10 parts by weight of oil, and 0.1 to 5 parts by weight of pigments (all by dry weight).

[0038] Here, feed for raising sea urchins can include both feed used for the purpose of enlarging the gonads, which are the edible part, and feed used for the purpose of increasing the shell diameter and weight of sea urchins.

[0039] The moisture, protein, lipid, and ash values ​​of the compound feed of the present invention and the feed ingredients blended therein are obtained by the analytical methods stipulated in the Feed Analysis Standards (Director-General of the Food Safety and Consumer Affairs Bureau, Ministry of Agriculture, Forestry and Fisheries, Japan). For example, the moisture content of the aquaculture feed of the present invention is 3% to 20% by weight per total weight, the protein content is 3% to 30% by weight per dry weight, the lipid content is 1% to 5% by weight per dry weight, and the ash content is 5% to 30% by weight per dry weight.

[0040] One embodiment of the compound feed of the present invention may be flat, plate-like, or thin-layered. In one embodiment, the thickness of the feed may be 0.01 to 20 mm, 0.1 to 10 mm, or 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, or 9 mm. To increase the specific surface area of ​​the feed, a thinner feed is preferable; however, if the feed is too thin, its shape retention in water may be reduced. If the feed contains a crosslinking agent, as described below, it can have high shape retention even when the feed is relatively thin.

[0041] One embodiment of the compound feed of the present invention may be extruded pellet (EP) feed and / or dry pellet (DP) feed. EP feed is feed produced by extrusion molding using an extruder, and the feed ingredients are molded under high temperature and pressure during the extrusion process using the extruder. DP feed is feed molded at a lower pressure than EP feed.

[0042] In another embodiment, the feed contains at least a cross-linking agent. The cross-linking agent may be a compound having multiple carboxyl groups, preferably a polycarboxylic acid. Specific examples include citric acid, malic acid, adipic acid, glutaric acid, succinic acid, malonic acid, oxalic acid, fumaric acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, anicotonic acid, and ethylenediaminetetraacetic acid (EDTA).

[0043] Here, the feed containing a crosslinking agent that is a polycarboxylic acid contains fibers with hydroxyl groups. Examples of fibers with hydroxyl groups include cellulose fibers, chitin fibers, and starch fibers. The multiple carboxyl groups of the crosslinking agent and the hydroxyl groups on the fibers form crosslinked structures, resulting in feed with high shape retention.

[0044] In this embodiment, the fibers may be the fine fibers described above, or may be non-fine fibers. This is because even if the fibers are not fine fibers, as long as they have hydroxyl groups, they can be crosslinked with polycarboxylic acids. Non-fine fibers are fibers that have not been defibrated, and specific examples of non-defibrated fibers include cellulose, starch, collagen, fibroin, and keratin.

[0045] In this embodiment, the feed may be one containing isolated or extracted fibers, but it does not necessarily have to be isolated or extracted fibers, and may be one containing a feed material containing a large amount of these fibers.Specific examples include feed containing one or more selected from seaweed powder containing cellulose, wheat bran and defatted rice bran, wheat flour containing starch, crab shell powder, shrimp shell powder and insect powder containing chitin, and fish scales and fish skin containing collagen.

[0046] The feed of this embodiment is produced by a production method including a step of contacting a cross-linking agent with fibers in the feed raw materials. One embodiment of the step of contacting a cross-linking agent with fibers in the feed raw materials may be a step of mixing the cross-linking agent with other raw materials containing fibers when forming the feed.

[0047] In one example of this embodiment, a powdered polycarboxylic acid is used as the crosslinking agent, and the polycarboxylic acid is mixed with other raw materials including the fibers in a molar ratio of 10 to 10,000 times the amount of the fibers. In another example of this embodiment, an aqueous solution of the polycarboxylic acid, the volume of which is 10 to 10,000 times the amount of the fibers, is mixed with other raw materials including the fibers.

[0048] Another example of the step of contacting the crosslinking agent with the fiber in the feed ingredients is a step of contacting the crosslinking agent with a feed that has been formed by blending ingredients excluding the crosslinking agent. This step can be carried out by immersing the feed, which has been previously formed using ingredients excluding the crosslinking agent and contains fiber, in an aqueous solution containing a polycarboxylic acid. The immersion time is not limited as long as the fiber in the feed is brought into contact with the polycarboxylic acid, but can be 5 seconds to 5 minutes, 30 seconds to 3 minutes, or 1 or 2 minutes.

[0049] Another aspect of the present invention provides a method for producing a compound feed, the method comprising the steps of applying a slurry containing fine fibers to a substrate and drying the substrate to which the slurry has been applied, wherein the slurry contains the above-mentioned feed ingredients and water.

[0050] The aforementioned EP feed and / or DP feed are obtained by molding and drying the feed ingredients, whereas the production method of the present invention involves applying a slurry containing the feed ingredients to a substrate and drying the substrate to obtain a thin layer of compound feed.

[0051] That is, the slurry contains water and feed ingredients. Specific examples of the feed ingredients include fiber (preferably fine fiber), seaweed powder, wheat flour, corn gluten meal, soybean meal, starch, fish oil, vegetable oil, salt, and pigments such as paprika powder. In one embodiment, the slurry contains 0.1 to 10 parts by weight of fine fiber and 99.9 to 90 parts by weight of feed ingredients other than the fine fiber. The feed ingredients other than the fine fiber may include 20 to 70 parts by weight of seaweed, 20 to 70 parts by weight of wheat flour, 1 to 10 parts by weight of oil, and 0.1 to 5 parts by weight of pigment (all by dry weight).

[0052] The slurry may contain 5 to 100 times, 10 to 50 times, or 20 to 30 times the weight of the feed ingredients. That is, the water content of the slurry may be 80 to 99% by weight, 90 to 98% by weight, or 94 to 96% by weight.

[0053] The means for applying the slurry to the substrate is not limited as long as the slurry is applied to the desired area of ​​the substrate, and specific examples include application using a brush, application using a roll coater, application using a dispenser, spray application using a spray nozzle, and dip application. The thickness of the applied slurry layer is not particularly limited, and as an example, it may be applied so that the thickness after drying is 0.001 to 1 mm, or 0.01 to 0.1 mm. This production method makes it possible to produce feed with a larger specific surface area than feed produced by the above-mentioned extrusion molding.

[0054] The substrate is not particularly limited, but specific examples include substrates made of resins such as polycarbonate and vinyl chloride, such as corrugated sheets used to induce metamorphosis in larvae of sea urchins and sea cucumbers. The substrate may also be made of wood. Another manufacturing method of the present invention includes the steps of applying a slurry containing fine fibers to a substrate, drying the substrate with the applied slurry, and peeling the dried slurry from the substrate. Alternatively, the dried slurry may be fed to the animals to be cultured together with the substrate with the applied slurry, without peeling it from the substrate. [Example]

[0055] The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0056] Formula feeds of Examples and Comparative Examples were prepared based on the compositions shown in Table 1. Cellish (registered trademark) KY100S (solid content 25% by weight, manufactured by Daicel Miraize Co., Ltd.) was used as the cellulose nanofiber (hereinafter sometimes referred to as CNF). The fiber length of the CNF was 0.25 to 0.45 mm, and the fiber diameter was 0.1 to 1.0 μm.

[0057] The composition of the compound feed in Comparative Example 1 was the same as that in Example 1, except that it did not contain CNF. The compound feeds in Comparative Examples 2 to 5 contained carboxymethyl cellulose (hereinafter sometimes referred to as CMC), starch, gelatin, or agar instead of the CNF in Example 1. Sunrose (registered trademark) F350HC-4 (manufactured by Nippon Paper Industries Co., Ltd.) was used as the CMC. It was confirmed that the CMC was not fibrous CMC.

[0058] Tap water was added to the raw materials listed in Table 1 in an amount 1.4 times the weight of the solid content, mixed in a mixer, and then extruded into a flat plate using an electric mincer (SG-50, manufactured by Fukushima Sangyo Co., Ltd.) through an extrusion nozzle 50 mm wide and 4 mm thick. The plate was then dried at 50°C until the moisture content was less than 5% by weight, yielding a compound feed. The thickness of the dried compound feed was approximately 2 mm. The compound feed of Example 1 contained 2% by weight of CNF per dry weight. In Comparative Example 6, commercially available extruded pellet (EP) feed for sea urchins was used.

[0059] [Table 1]

[0060] 2 to 5 g of the compound feed of the Example or Comparative Example was placed in a container containing 100 mL of seawater and shaken for 30 minutes at 200 rpm and an amplitude of 25 mm using a shaker (MMS, manufactured by Tokyo Rikakikai Co., Ltd.) in an environment adjusted to 5, 10, 15, 20, 25, 30, or 35°C. The solid matter collected by filtration through a 1 mm mesh was dried at 70°C for 24 hours and weighed. The residual rate per dry weight, i.e., input weight (per dry matter) / recovered weight (per dry matter) × 100, was calculated. The results are shown in Tables 2 to 4. The CNF-containing feed (Example 1) showed a higher residual rate than the other feeds at most temperature ranges, and significant differences were observed from Comparative Example 1 at most temperature ranges.

[0061] [Table 2]

[0062] [Table 3]

[0063] [Table 4]

[0064] Furthermore, the compound feeds of Example 1 and Comparative Examples 1, 2, and 6 were shaken for 1 to 4 hours under the same conditions with the seawater temperature maintained at 20°C, and the residual rate per dry weight was measured. The results of the average residual rate are shown in Figure 1. The compound feed containing 2 wt% CNF (Example 1) showed significantly higher shape retention than the other feeds.

[0065] Furthermore, the compound feeds of Example 1 and Comparative Examples 1, 2, and 6 were shaken for 6 days at a rotation speed of 15 rpm while maintaining the seawater temperature at 20°C. These shaking conditions reproduced the typical shaking conditions that occur in cages or fish pens installed in the ocean. On days 1, 2, 4, and 6, the weight of the solid matter collected by filtration through a 1 mm mesh was measured. Because the feed absorbs seawater, shape retention was evaluated as a weight ratio using the weight measured after 1 day as the denominator and the weights measured on days 2, 4, and 6 as the numerators. The results of the average weight ratios are shown in Figure 2. The compound feed containing 2 wt% CNF (Example 1) showed significantly higher shape retention than the other feeds.

[0066] Next, the effect of the thickness of the compound feed of the Examples on shape retention was investigated. Plate-shaped feeds of varying thicknesses were prepared using the same formulation as in Example 1 and Comparative Example 1. Tap water was added to the ingredients listed in Table 1 in an amount 1.4 times the weight of the solid content, and the mixture was mixed in a mixer. The mixture was then extruded into plates using an electric mincer (SG-50, manufactured by Fukushima Sangyo Co., Ltd.) through an extrusion nozzle 50 mm wide and 1, 2, 3, 4, or 5 mm high. The mixture was then dried at 50°C until the moisture content was less than 5% by weight, yielding a compound feed. The thickness of the dried compound feed was measured to be 0.7 ± 0.2 mm to 2.7 ± 0.2 mm (mean ± standard deviation).

[0067] 2 to 5 g of formula feed was placed in a container containing 100 mL of tap water and shaken at room temperature for 30 minutes using a shaker (SHAKER SRR-2, AS ONE Corporation) at an amplitude of 30 mm and a rotation speed of 200 rpm. The solid matter collected by filtration through a 1 mm mesh was dried at 70°C for 24 hours and weighed, and the residual rate per dry weight, i.e., input weight (per dry matter) / recovered weight (per dry matter) × 100, was calculated. The results are shown in Table 5. At all thicknesses, the residual rate of Example 1 was higher than that of Comparative Example 1.

[0068] [Table 5]

[0069] Next, we investigated the effect of CNF content on shape retention. Tap water was added to the raw materials listed in Table 6 in an amount 1.4 times the solid content by weight. After mixing in a mixer, the mixture was extruded into a flat plate using an electric mincer (SG-50, manufactured by Fukushima Sangyo Co., Ltd.) through an extrusion nozzle 50 mm wide and 4 mm high. The mixture was then dried at 50°C until the moisture content was less than 5% by weight, yielding a compound feed. The compound feeds in the examples contained 1, 2, or 4% by weight of CNF per dry weight.

[0070] [Table 6]

[0071] Waves with the same conditions as those experienced by sea urchin farming cages placed in the ocean were artificially generated to confirm whether the compound feed remained in the cages. The sea urchin farming cages used had outer walls made of 10 mm mesh. Three cages were prepared for each compound feed of the Comparative Example and Example, and 100 g of the compound feed of the Comparative Example and Example was placed in each cage. The cages were placed in a tank filled with seawater and exposed to a water temperature of approximately 16°C with a flow period of 6 seconds and a maximum flow rate of 0.1 m / s for 4 hours, after which the weight of the recovered compound feed was measured. The results are shown in Figure 3. The recovered weight of the compound feeds of Examples 1 to 3 was significantly higher than that of Comparative Example 1.

[0072] Furthermore, the compound feed of Example 1, which contained 2% by weight of CNF and was molded to a thickness of approximately 2 mm after drying, and a commercially available compound feed (Comparative Example 6) were allowed to absorb seawater at a temperature of approximately 9°C for 48 hours. After the seawater was drained using a colander, 1 kg of each was placed in the above-mentioned sea urchin aquaculture cage. The cages were placed in a tank filled with seawater, and waves with a height of 0.2 m were generated at a water temperature of approximately 9°C with a 5-second cycle. After 6 hours, the feed was recovered and its weight was measured after draining the water using a colander. Figure 4 shows a photograph taken immediately before recovery, and Table 7 shows the weights and recovery rates at the start and end of the recovery period. The compound feed of Example 1 showed a higher recovery rate than the commercially available compound feed.

[0073] [Table 7]

[0074] The shape retention of compound feed containing CNF of various fiber lengths and / or diameters, and fine fibers composed of fibers other than cellulose, was compared. The solid content, fiber length, and fiber diameter of the fine fibers contained in the compound feed are shown in Table 8. Chitin nanofiber (hereinafter sometimes referred to as "chitin NF") was prepared as follows.

[0075] The shells of Japanese oyster crab (Paralithodes brevipes) were subjected to alkali treatment (refluxing in 5 wt% potassium hydroxide aqueous solution for 6 hours) and acid treatment (immersion in 1 M hydrochloric acid at room temperature for 2 days), followed by washing with isopropanol. They were coarsely ground using a commercially available juicer mixer to prepare a suspension with a solids concentration of 0.8 wt%. They were then ground twice at 10,000 rpm for 30 seconds using a shaft generator (S50N-G45G-ST, IKA) and a homogenizer (T50 digital ULTRA-TURRAX®, IKA), followed by wet defibration using a stone mill grinder (Masscolloider MKCA6-3, Masuko Sangyo Co., Ltd.). The resulting chitin NF was insoluble in water and had a fiber diameter of 0.02–0.1 μm. In addition, bleached kraft pulp derived from softwood used for paper production (hereinafter sometimes referred to as "paper pulp") was also used as cellulose that had not been subjected to defibration treatment.

[0076] [Table 8]

[0077] Each of the above-mentioned fibers was added to the raw material of Comparative Example 1 listed in Table 1 at a content of 0.5, 1, 2, 4, or 8% by weight. Tap water was added in an amount 1.4 times the weight of the solid content, and after mixing in a mixer, the mixture was poured into a resin cup and molded (i.e., molding was performed without applying any pressure other than that generated by the weight of the feed raw material and tap water), and dried at 50°C until the moisture content was less than 5% by weight, to obtain a compound feed. The thickness of the compound feed after drying was approximately 2 mm.

[0078] 2-5 g of formula feed was placed in a container containing 100 mL of tap water and shaken at room temperature using a shaker (SHAKER SRR-2, AS ONE Corporation) at a 30 mm amplitude and 200 rpm for 30 minutes. The solids collected by filtration through a 1 mm mesh were dried at 70°C for 24 hours and weighed, and the residual rate per dry weight, i.e., input weight (per dry matter) / recovered weight (per dry matter) × 100, was calculated. The results are shown in Table 9. Formula feed containing 0.5 wt% to 8 wt% (both dry weights) of CNF and chitin NF showed a higher residual rate than formula feed containing the same amount of paper pulp.

[0079] [Table 9]

[0080] Formula feeds with the same composition as in Comparative Example 1 and formula feeds containing 1 or 2 parts by weight of Celish (registered trademark) KY100S were poured into resin cups and molded in the same manner as described above, and then dried to obtain formula feeds. The thickness of the formula feeds after drying was approximately 2 mm. These formula feeds were immersed in a 2 mol / L aqueous citric acid solution for 2 minutes, dried at room temperature overnight, and the residual rate was measured using the method described above.

[0081] The results of measuring the residual rate are shown in Table 10. Feed containing 1-2 wt% CNF and soaked in citric acid solution showed a residual rate equal to or higher than that of feed containing 8 wt% CNF but no citric acid. Furthermore, compound feed containing no CNF also showed a residual rate equal to or higher than that of 2 wt% CNF when soaked in citric acid solution.

[0082] [Table 10]

[0083] A rearing test of northern sea urchins (Mesocentrotus nudus) was conducted using the compound feed of Example 1 (containing 2% by weight of CNF, approximately 2 mm thick after drying). Ten northern sea urchins (shell diameter 41.5±1.4 mm, weight 28.3±3.6, both mean ± standard deviation) were used and fed once a week with 10% by weight of the total weight of the feed for 10 weeks. At the start and end of the rearing period, 10 individuals were dissected and their gonad somatic index (GSI) was measured. The changes in GSI are shown in Figure 5. The compound feed of Example 1 significantly increased the GSI of the northern sea urchins.

[0084] Furthermore, compound feeds (Examples 11 to 13) containing 50 to 75 wt. % of Celish (registered trademark) KY100S per dry weight were prepared. Tap water was added in an amount four times the weight of the solid content of the raw materials listed in Table 11, mixed in a mixer, poured into a resin cup, molded, and dried at 50°C until the moisture content was less than 5 wt. The compound feed of Example 13 had the same composition as Example 12, and after drying, it was immersed in a 2 mol / L aqueous citric acid solution for 2 minutes and then dried at room temperature.

[0085] [Table 11]

[0086] When the compound feeds of Examples 11 to 13 were introduced into an aquarium containing sea urchins, it was confirmed that the compound feeds had a high degree of shape retention, and it was also confirmed that the sea urchins ate the compound feeds of Examples 11 to 13.

[0087] Formula feed was produced using a method including a step of applying a slurry to a substrate. Tap water was added in an amount 20 times by weight of the solid content of the raw materials listed in Table 12, and the mixture was mixed in a mixer for 15 minutes or more to obtain a slurry. The water content of the slurry was 95% by weight. The slurry was applied to a corrugated polycarbonate plate and dried overnight at room temperature to obtain the formula feed of Example 21. The thickness of the feed of Example 21 after drying was 0.01 mm to 0.03 mm.

[0088] [Table 12]

[0089] Thirty juvenile northern purple sea urchins were fed weekly with the formulated feed of Example 1 or the formulated feed of Example 21, each in an amount of 15% by weight of the total weight of the sea urchins. The changes in average weight at the start, one month, and two months are shown in Figure 6. The sea urchins fed with the formulated feed of Example 21 showed a weight gain equivalent to that of the sea urchins fed with the formulated feed of Example 1.

[0090] The present invention further includes the following aspects. [Aspect A1] A compound feed containing water-insoluble fine fibers, or a compound feed containing water-insoluble fine fibers, wherein the fine fibers are defibrated fine fibers. [Aspect A2] The compound feed according to aspect A1, wherein the fine fibers are fine cellulose fibers and / or fine chitin fibers. [Aspect A3] The fine fibers are fine fibers having no carboxymethyl groups. Fine The compound feed according to aspect A1 or A2, wherein the compound feed is fiber. [Aspect A4] The compound feed according to any one of A1 to A3, wherein the fine fibers are contained in an amount of 0.1 to 80% by weight based on dry weight. [Aspect A5] The compound feed according to any one of A1 to A4, wherein the fine fibers have a fiber diameter of 0.02 to 50 μm. [Aspect A6] The compound feed according to any one of A1 to A5, wherein the fine fibers have a fiber length of 0.25 to 1.5 mm. [Aspect A7] The compound feed according to any one of A1 to A6, further comprising a crosslinking agent having multiple carboxyl groups. [Aspect A8] The compound feed according to aspect A7, wherein the cross-linking agent is citric acid. [Aspect A9] The compound feed according to any one of Aspects A1 to A8, wherein the compound feed is for sea urchin, sea cucumber, and / or abalone. [Aspect B1] applying a slurry containing the feed ingredient to a substrate; and drying the substrate to which the slurry has been applied. [Aspect B2] The method of claim B1, wherein the slurry contains water-insoluble fine fibers. ,before The method according to aspect B1, wherein the slurry contains water-insoluble fine fibers, and the fine fibers are defibrated fine fibers. The manufacturing method according to aspect B1, wherein the slurry contains water-insoluble fine fibers, and the fine fibers are fine fibers having no carboxymethyl groups; or the manufacturing method according to aspect B1, wherein the slurry contains water-insoluble fine fibers, and the fine fibers are defibrated fine fibers having no carboxymethyl groups. . [Aspect B3] The method according to aspect B1 or B2, wherein the slurry contains the fine fibers in an amount of 0.1 to 80% by weight based on the dry weight, and the water content of the slurry is 80 to 99% by weight. [Aspect B4] The method according to any one of Aspects B1 to B3, wherein the coating step is a dip coating step. [Aspect B5] The production method according to any one of Aspects B1 to B4, wherein the compound feed is a compound feed for sea urchins, sea cucumbers, and / or abalones. [Aspect B6] The method according to any one of Aspects B2 to B5, wherein the fine fibers are fine cellulose fibers and / or fine chitin fibers. [Aspect B7] The fine fibers are fine fibers having no carboxymethyl groups. FineThe method according to any one of aspects B2 to B6, wherein the [Aspect B8] The method according to any one of aspects B2 to B7, wherein the fine fibers are contained in an amount of 0.1 to 80% by weight based on dry weight. [Aspect B9] The method according to any one of aspects B2 to B8, wherein the fine fibers have a fiber diameter of 0.02 to 50 μm. [Aspect B10] The method according to any one of aspects B2 to B9, wherein the fine fibers have a fiber length of 0.25 to 1.5 mm. [Aspect B11] The method of any one of aspects B1 to B10, further comprising a crosslinking agent having multiple carboxyl groups. [Aspect B12] The method of manufacturing of aspect B11, wherein the cross-linking agent is citric acid. [Aspect C1] mixing a feed material containing hydroxyl-containing fiber; contacting the fibers with a cross-linking agent having multiple carboxyl groups; Method for manufacturing compound feed. [Aspect C2] A method for producing a compound feed according to aspect C1, wherein the fibers are water-insoluble fine fibers and the cross-linking agent is citric acid; or a method for producing a compound feed according to aspect C1, wherein the fibers are defibrated water-insoluble fine fibers and the cross-linking agent is citric acid. [Aspect C3] The method according to aspect C2, wherein the fine fibers are fine cellulose fibers and / or fine chitin fibers. [Aspect C4] The fine fibers are fine fibers having no carboxymethyl groups. Fine The method of any of aspects C2 or C3, wherein the [Aspect C5] The method according to any one of Aspects C2 to C4, wherein the fine fibers are contained in an amount of 0.1 to 80% by weight based on dry weight. [Aspect C6] The method according to any one of aspects C2 to C5, wherein the fine fibers have a fiber diameter of 0.02 to 50 μm. [Aspect C7] The method according to any one of aspects C2 to C6, wherein the fine fibers have a fiber length of 0.25 to 1.5 mm. [Aspect C8] The production method according to any one of Aspects C1 to C7, wherein the compound feed is a compound feed for sea urchins, sea cucumbers, and / or abalones. [Aspect D1] Use of water-insoluble fine fibers in maintaining the shape of compound feed for aquatic animals, or use of water-insoluble fine fibers in maintaining the shape of compound feed for aquatic animals, wherein the fine fibers are defibrated fine fibers. [Aspect D2] The use according to aspect D1, wherein the fine fibers are fine cellulose fibers and / or fine chitin fibers. [Aspect D3] The fine fibers are fine fibers having no carboxymethyl groups. Fine The use according to any one of aspects D1 or D2, wherein the [Aspect D4] The use according to any one of aspects D1 to D3, wherein the fine fibers have a fiber diameter of 0.02 to 50 μm. [Aspect D5] The use according to any one of aspects D1 to D4, wherein the fine fibers have a fiber length of 0.25 to 1.5 mm. [Aspect D6] The use according to any one of aspects D1 to D5, wherein the fine fibers are contained in an amount of 0.1 to 80% by weight based on dry weight. [Aspect D7] The use according to any one of aspects D1 to D6, wherein the compound feed is a compound feed for sea urchins, sea cucumbers, and / or abalones. [Aspect E1] A compound feed in which the compound feed is immersed in tap water at room temperature, shaken at an amplitude of 30 mm and a rotation speed of 200 rpm for 30 minutes, and then filtered through a mesh with 1 mm openings, with the dry weight of the solids recovered being 30% or more of the dry weight of the compound feed before shaking. [Aspect E2] A compound feed according to aspect E1, which contains water-insoluble fiber, or a compound feed according to aspect E1, which contains water-insoluble fiber, wherein the fiber is defibrated fine fiber. [Aspect E3] The fibers include fine cellulose fibers, fine chitin fibers, and fine fibers having no carboxymethyl groups. Fine The compound feed according to aspect E2, wherein the feed is fiber, and / or paper pulp. [Aspect E4] The compound feed according to either aspect E2 or E3, wherein the fiber is contained in an amount of 0.1 to 80% by dry weight. [Aspect E5] The compound feed according to any one of aspects E2 to E4, wherein the fibers have a fiber diameter of 0.02 to 50 μm and / or a fiber length of 0.25 to 1.5 mm. [Aspect E6] The compound feed according to any one of aspects E1 to E5, further comprising a cross-linking agent having multiple carboxyl groups. [Aspect E7] The compound feed according to aspect E6, wherein the cross-linking agent is citric acid. [Aspect E8] The compound feed according to any one of Aspects E1 to E7, wherein the compound feed is for sea urchin, sea cucumber, and / or abalone.

Claims

1. A compound feed containing water-insoluble fine fibers, the fine fibers being defibrated and having no carboxymethyl groups.

2. 2. The compound feed according to claim 1, wherein the fine fibers are fine cellulose fibers and / or fine chitin fibers.

3. 3. The compound feed according to claim 2, wherein the fine fibers are contained in an amount of 0.1 to 80% by weight based on dry weight.

4. 3. The compound feed according to claim 2, wherein the fiber diameter of the fine fibers is 0.02 to 50 μm.

5. 3. The compound feed according to claim 2, wherein the fiber length of the fine fibers is 0.25 to 1.5 mm.

6. The compound feed according to claim 2, further comprising a cross-linking agent having multiple carboxyl groups.

7. 7. The compound feed according to claim 6, wherein the cross-linking agent is citric acid.

8. The compound feed according to claim 1, A compound feed in which the compound feed is immersed in tap water at room temperature, shaken at an amplitude of 30 mm and a rotation speed of 200 rpm for 30 minutes, and then filtered through a mesh with 1 mm openings, with the dry weight of the solids recovered being 30% or more of the dry weight of the compound feed before shaking.

9. The compound feed according to any one of claims 1 to 8, wherein the compound feed is a compound feed for sea urchin, sea cucumber, and / or abalone.

10. applying a slurry containing the feed ingredient to a substrate; and drying the substrate on which the slurry has been applied.

2. The method for producing a compound feed according to claim 1, wherein the slurry contains defibrated fine fibers that do not have carboxymethyl groups and are insoluble in water.

11. The method according to claim 10, wherein the slurry contains the fine fibers in an amount of 0.1 to 80% by weight based on dry weight, and the water content of the slurry is 80 to 99% by weight.

12. The method of claim 10 , wherein the coating step is a dip coating step.

13. mixing a feed material containing hydroxyl-containing fiber; contacting the fibers with a cross-linking agent having a plurality of carboxyl groups; The fibers are defibrated, water-insoluble fine fibers that do not have carboxymethyl groups. A method for producing the compound feed according to claim 1.

14. The method of claim 13, wherein the cross-linking agent is citric acid.

15. 14. The production method according to claim 13, wherein the compound feed is immersed in tap water at room temperature, shaken at an amplitude of 30 mm at a rotation speed of 200 rpm for 30 minutes, and then filtered through a mesh with 1 mm openings, so that the dry weight of the solids recovered is 30% or more of the dry weight of the compound feed before shaking.

16. The production method according to any one of claims 10 to 15, wherein the compound feed is a compound feed for sea urchin, sea cucumber, and / or abalone.

17. 1. Use of water-insoluble fine fibers in maintaining the shape of compound feed for aquatic animals, wherein the fine fibers are defibrated fine fibers having no carboxymethyl groups.

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