Aquaculture feed, method for producing aquaculture feed, aquaculture method, and farmed fish

Abstract

To provide aquaculture feed for cultivating fish that are easy to be eaten even down to the bones, an aquaculture feed manufacturing method, an aquaculture method, and cultivated fish.SOLUTION: The aquaculture feed of the present invention contains a substance that binds to phosphorus to insolubilize phosphorus in the feed or in the fish's body. The substance contains at least one of aluminum salts, ferric salts, calcium hydroxide, and calcium salts. When ferric salts are included, reducing substances must be excluded from the feed. In that case, a low-phosphorus feed containing a reducing substance is fed in combination as a loading feed once or twice a week. Low-phosphorus feed can be made from washed chicken meat, feather meal, blood meal, or soybean meal as the main ingredients, but other low-phosphorus ingredients may also be used.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a culture feed for feeding fish during fish farming, a method for manufacturing the culture feed, a culture method, and cultured fish.

Background Art

[0002] Conventionally, various types of fish have been cultured by various methods. For example, Patent Document 1 below discloses a culture feed containing inosine. It is described in Patent Document 1 below that growth decline of fish due to low fish meal can be prevented or reduced.

[0003] For small fish up to about 20 cm in body length, they may be eaten whole by being grilled with salt, deep-fried, or boiled, etc., but many people dislike eating even the bones. According to recent statistical surveys, the "alienation from fish" among the general public, especially the younger generation, is becoming serious, and the biggest reason is "dislike of bones". Therefore, culturing fish that are easy to eat even with bones is considered effective in stopping the alienation from fish among the general public and various health disadvantages caused thereby. Note that such matters are not described in Patent Document 1.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a culture feed for culturing fish that are easy to eat even with bones, a method for manufacturing the culture feed, a culture method, and cultured fish.

Means for Solving the Problems

[0006] The aquaculture feed of the present invention contains a substance that binds to phosphorus and makes it insoluble in the feed and in the fish's body. Alternatively, it uses raw materials whose phosphorus content has been reduced by washing as its main ingredient. [Effects of the Invention]

[0007] According to this invention, fish are unable to adequately digest and absorb phosphorus in their feed, resulting in poorer bone formation than usual. This leads to lower bone density and softer bones than normal. When eating the fish whole, the bones become easier to eat. [Brief explanation of the drawing]

[0008] [Figure 1] This is a photograph showing the bones of a minnow that was fed aquaculture feed supplemented with Al2(SO4)3. [Figure 2] (a) is a photograph of the bones of a moroko fish that was fed a low-phosphorus feed (loading feed), and (b) is a photograph of the bones of a moroko fish that was fed a commercially available aquaculture feed. [Figure 3] (a) is a magnified photograph of the bones of a moroko fish fed with aquaculture feed containing chicken and ferric salts, and (b) is a magnified photograph of the bones (same area) of a moroko fish fed with commercially available aquaculture feed. [Modes for carrying out the invention]

[0009] The aquaculture feed, the method for producing the aquaculture feed, the aquaculture method, and the farmed fish of the present invention will be explained with reference to the drawings.

[0010] The aquaculture feed of the present invention is intended for feeding fish. The fish to be farmed are small freshwater or saltwater fish up to about 20 cm in length, and it is preferable that they be fish that can be eaten whole depending on the cooking method. Examples of fish include Japanese minnows, small crucian carp, juvenile carp, sweetfish, dace, rainbow trout, Biwa trout, amago trout, char, and loach.

[0011] Furthermore, larger fish may also be used, such as Atlantic salmon, trout salmon, other salmon species, yellowtail, tuna, catfish, and eels.

[0012] [Embodiment 1] [Aquaculture feed] Generally, the main components of aquaculture feed include plant-based ingredients, animal-based ingredients, or both. Plant-based ingredients include soybean oil meal, soy protein, corn gluten, rice bran, wheat bran, rapeseed oil meal, and corn. Animal-based ingredients include fish meal, chicken meal, feather meal, blood meal, squid meal, and krill meal.

[0013] The aquaculture feed according to this embodiment contains a substance that insolubilizes phosphorus in the feed, in the fish's body, or both. Examples of such phosphorus-insolubilizing substances include aluminum salts, ferric salts, calcium hydroxide (Ca(OH)2), and calcium carbonate (CaCO3). At least one of these is included in the aquaculture feed.

[0014] Aluminum salts include Al2(SO4)3 and AlK(SO4)2. Ferric salts include FeCl3, Fe2(SO4)3 and FeC6H5O7.

[0015] In plant-based feed, approximately two-thirds of the total phosphorus is in the form of phytic phosphorus, and the remaining one-third is in the form of inorganic phosphate. Phytic phosphorus becomes insoluble by reacting with calcium hydroxide, while inorganic phosphate becomes insoluble by reacting with aluminum salts or ferric salts to produce insoluble AlPO4 and FePO4. Therefore, by including calcium hydroxide, aluminum salts, or ferric salts in feed made from plant-based materials, the absorption of phosphorus into the body of fish can be suppressed. On the other hand, animal-based feed contains hydroxyapatite Ca derived from bones and scales. 10It contains (PO4)6(OH)2, phosphoproteins, and inorganic phosphate. Of these, inorganic phosphate can inhibit the absorption of phosphorus in the fish intestinal tract by being combined with aluminum salts or ferric salts. Phosphoproteins can also inhibit the absorption of phosphorus by binding to aluminum salts or ferric salts after phosphorus is released in the fish intestinal tract. For hydroxyapatite, the absorption of phosphorus can be inhibited by adding Ca(OH)2, CaCO3, or both to the feed to neutralize stomach acid and prevent solubilization by stomach acid (maintaining the insolubility of phosphorus in the stomach). However, this does not apply to fish that do not have a stomach (such as minnows, carp, and crucian carp) as they do not secrete stomach acid.

[0016] It is preferable that aluminum salts, ferric salts, calcium hydroxide, and calcium carbonate be included in the total weight of the aquaculture feed at a concentration of 5% or less (0% is not included). When aluminum salts, ferric salts, calcium hydroxide, and calcium carbonate are added to multiple types of aquaculture feed, the total amount added may slightly exceed 5%, for example, 6% or less (0% is not included). Since ingesting large amounts of aluminum salts can be harmful to fish, the aluminum salt should be included in the aquaculture feed at a concentration of 2% or less (0% is not included), preferably 1% or less (0% is not included). In addition, calcium carbonate and calcium hydroxide may be used in combination at a concentration of 8% or less (0% is not included), preferably 1-8%.

[0017] The above explanation described the upper limit. Regarding the lower limit, it is preferable that aluminum salts be present in the total weight of the aquaculture feed at 0.01% or more, ferric salts at 0.01% or more, calcium hydroxide at 0.1% or more, and calcium carbonate at 1% or more. This is because if the amount of aluminum salts, etc., is too low, the effect will be lost.

[0018] While calcium hydroxide and calcium carbonate are described, other calcium salts may also be used. For example, calcium lactate, calcium acetate, calcium chloride, and calcium sulfate are examples of calcium salts.

[0019] [Method for Producing Aquaculture Feed] The method for producing aquaculture feed according to this embodiment includes preparing raw materials including the above-described plant raw materials, animal raw materials, or both, pulverizing the raw materials, and stirring them. If the raw materials are originally in a desired size or smaller, such as granular or powdery, the pulverization step of the raw materials may be omitted. A substance that insolubilizes phosphorus, specifically aluminum salts, ferric salts, calcium hydroxide, calcium carbonate, etc., is added to the stirred raw materials, and an appropriate amount of water is added and mixed. In order to sufficiently react the phosphorus contained in the raw materials with the additives, the mixture is left standing at room temperature (15 - 25°C) for 3 hours or more. Then, it is formed into pellets and dried. Aquaculture feed is produced through the above steps.

[0020] Phosphorus is an essential nutrient richly contained in various foods and feed raw materials. Phosphorus absorbed from foods and feeds binds with calcium and becomes the main component of hydroxyapatite, that is, bone. By containing aluminum salts, ferric salts, calcium hydroxide, or calcium carbonate in the aquaculture feed as described above, the phosphorus in the feed can be insolubilized, and the absorption of phosphorus in the fish's body can be inhibited. The fish will be in a state of phosphorus deficiency, and it will be difficult for bones to form. As a result, the bones become soft, and it becomes easier to eat the whole fish.

[0021] [Method for Culturing Fish] The method for culturing fish according to this embodiment includes feeding the above-described aquaculture feed to fish in place of conventional aquaculture feed. In a conventional aquaculture method, there is no need to newly construct equipment other than replacing the aquaculture feed with the aquaculture feed of the present invention. The feeding period is preferably about 1 month before shipment (sale).

[0022] In this embodiment, fish may be fed not just one type of aquaculture feed, but multiple types of aquaculture feed. That is, fish may be fed aquaculture feed with different types or combinations of aluminum salt, ferric salt, calcium hydroxide, and calcium carbonate added to it. It is not that the composition of aluminum salt, ferric salt, calcium hydroxide, and calcium carbonate added to the aquaculture feed is different, but rather that their content may differ.

[0023] [Farmed fish] The farmed fish according to this embodiment are fish that have been fed the above-mentioned aquaculture feed, resulting in a phosphorus deficiency, which can lead to bone failure or softening of the bones. Soft bones may also bend and deform. The farmed fish of this invention have a bone ash content of less than 45% (by dry weight), or at least one of the ribs, neural spines, or vascular spines has a wavy deformation. When eaten whole, such as grilled, deep-fried, or simmered, the bones can be eaten without worry, making it easier to eat.

[0024] Furthermore, a phosphorus deficiency inhibits oxidative phosphorylation (the reaction that synthesizes ATP in the inner mitochondrial membrane). As a result, fat, which serves as a substrate, accumulates in the body, producing farmed fish with a high fat content. In addition, along with the increase in fat, fat-soluble functional components such as EPA and DHA also increase, and various ripple effects are expected, including the prevention of lifestyle-related diseases and dementia, brain development (in infants), and more. Therefore, for larger fish (such as Atlantic salmon, trout salmon, other salmon species, yellowtail, tuna, catfish, and eels) that are not eaten whole, there is no benefit in softening the bones. However, by feeding them this aquaculture feed to create a phosphorus deficiency, it is possible to produce farmed fish with a high fat content, improving the taste of farmed fish and increasing their added value. In other words, an increase in the consumption of farmed fish in general is expected.

[0025] [Embodiment 2] [Aquaculture feed] The aquaculture feed according to this embodiment contains ferric salt, and furthermore, the amount of reducing substances in the aquaculture feed is less than the amount that can react with the contained ferric salt. Preferably, reducing substances should be excluded. This is because ferric salt reacts with reducing substances, changing iron from trivalent to divalent, and the effect of suppressing phosphorus absorption is lost. Examples of reducing substances include oils and fats, ascorbic acid, vitamin E, and vitamin A. It is preferable to exclude reducing substances as much as possible by selecting the raw materials for the aquaculture feed, but at least by keeping the equivalent amount of reducing substances in the feed lower than the equivalent amount of ferric salt, the effect of suppressing phosphorus absorption is exerted without the ferric salt in the feed being lost through reaction.

[0026] [Method for producing aquaculture feed] The method for producing aquaculture feed according to this embodiment is the same as the method for producing the first embodiment described above, but is characterized by the use of ferric salt as a substance to insolubilize phosphorus, and by selecting and using plant and animal raw materials that do not contain reducing substances as much as possible, or by including a step to remove reducing substances from the raw materials. The step to remove reducing substances is a degreasing step to remove oils and fats.

[0027] [Fish farming methods] The aquaculture method according to this embodiment involves feeding the fish with aquaculture feed that contains ferric salt as a substance that insolubilizes phosphorus, and has reduced amounts of reducing substances excluded or reduced in quantity. However, if only feed that excludes reducing substances, or contains less reducing substances than ferric salt (in terms of equivalent weight), the fish will lack reducing substances such as oils and vitamins necessary for growth, increasing the risk of health problems due to deficiency. Therefore, it is preferable to feed the fish with feed containing a large amount of reducing substances at a certain frequency. For example, the health of farmed fish can be maintained by feeding them feed containing the above-mentioned reducing substances at least once every 1 to 2 weeks. The aquaculture feed containing reducing substances does not need to be fed regularly, but may be fed according to the health condition of the fish, and can serve as a nutritionally fortified feed or nutritional supplement to compensate for nutritional deficiencies caused by the exclusion of reducing substances.

[0028] [Farmed fish] The farmed fish according to this embodiment are fed a farming feed containing the ferric salt of the present invention and free of reducing substances, resulting in a phosphorus-deficient state. As a result, similar to Embodiment 1, skeletal formation is inhibited and the bones become softer. Furthermore, as mentioned above, phosphorus-deficient fish have increased body fat and become more flavorful, thus improving their palatability.

[0029] [Embodiment 3] [Aquaculture feed] The aquaculture feed of this embodiment is a low-phosphorus aquaculture feed mainly composed of washed feed ingredients. Specific feed ingredients to be washed include chicken meat, feather meal, blood meal, and soybean meal.

[0030] The low-phosphorus aquaculture feed described above is a feed in which phosphorus has been deficient or insufficient by washing the aforementioned feed ingredients.

[0031] [Method for producing aquaculture feed] The method for producing aquaculture feed according to this embodiment is characterized by reducing the phosphorus content by washing the feed ingredients. Chicken meat, a feed ingredient, is a food with a relatively low phosphorus content (phosphorus content is 0.15-0.22% by wet weight, equivalent to 0.55-0.87% by dry weight in the Standard Tables of Food Composition in Japan). Feather meal (phosphorus content 0.20% by dry weight), blood meal (same 0.31% by dry weight), and soybean meal (same 0.67% by dry weight) are also ingredients with relatively low phosphorus content. The phosphorus content of all of these ingredients is 1% or less by dry weight. Low-phosphorus aquaculture feed is obtained by further reducing the phosphorus content of such ingredients by washing, etc., to a phosphorus content of 0.3% or less by dry weight. Alternatively, the aquaculture feed according to this embodiment may be a low-phosphorus aquaculture feed obtained by mixing feed ingredients whose phosphorus content has been reduced by such washing with other feed ingredients. In that case, it is preferable that the low-phosphorus aquaculture feed mentioned above makes up 5% or more of the total aquaculture feed. Examples of liquids used to wash the feed ingredients include water (including pure water), saline solution, seawater, dilute acidic water, and dilute alkaline water.

[0032] When using chicken as a feed ingredient, the process includes washing the chicken with cold water. To minimize protein loss during washing, a heating step before washing may be included. Table 1 compares the concentration of eluted phosphorus extracted from raw or heated chicken using distilled water or a 1% citric acid aqueous solution by centrifugation, followed by color development with ammonium molybdate, absorbance at a wavelength of 680 nm, and eluted phosphorus concentration. It can be seen that when extracted with distilled water, heated chicken yields more eluted phosphorus. Specifically, for example, chicken can be heated in boiling water for about 3 minutes, then ground through a coarse plate (φ6~9 mm), placed in a cotton bag, and washed three times with cold water at 5~10°C, followed by repeated dewatering. The phosphorus content in the chicken treated in this way was 0.24% (dry weight basis). Furthermore, to promote the digestion of phosphoproteins by the intrinsic enzymes and increase the amount of eluted phosphorus, the chicken may be frozen before heating, then thawed and aged at 42~45°C for 3~12 hours. Table 2 compares the absorbance of samples that were not aged after refrigeration and those that were aged at 45°C for 1 hour and 3 hours. It can be seen that adding the aging process increases the absorbance and thus the amount of phosphorus released. Table 3 compares the absorbance and released phosphorus concentration of samples that were refrigerated before heating, aged at 42°C for 12 hours, frozen, thawed, and refrigerated, and frozen, thawed, refrigerated, and then aged. It can be seen that the more samples that underwent the freezing, thawing, and aging process, the more phosphorus was released.

[0033] When using feather meal as a feed ingredient, while maturation and heating have little effect in reducing phosphorus content, repeatedly washing and dewatering with dilute hydrochloric acid is very effective. Specifically, feather meal placed in a cotton bag was washed once with 0.03N HCl, once with 0.02N HCl, and finally once with tap water, resulting in a phosphorus content of 0.17% (dry weight). Table 4 compares the absorbance of refrigerated and matured feather meal, showing that the matured feather meal has a higher absorbance, suggesting a higher concentration of eluted phosphorus. Table 5 compares feather meal washed with tap water or hydrochloric acid, both at a washing temperature of 100°C, showing that the hydrochloric acid-treated feather meal has a higher absorbance, suggesting a higher concentration of eluted phosphorus. Table 6 compares absorbance with varying normalities of hydrochloric acid, showing that the higher the hydrochloric acid concentration, the higher the absorbance, suggesting a higher concentration of eluted phosphorus.

[0034] When using blood meal as a feed ingredient, it is necessary to heat-denaturate it to improve the yield after washing. As a specific example, the process used in the production of konjac noodles (making a paste into threads and pouring it into boiling water to instantly heat-coagulate it) is used. In the case of blood meal, this forms porous noodles. By placing these in a cotton bag and washing and dewatering them three times with cold water, the phosphorus content can be significantly reduced. The phosphorus content of the blood meal treated in this way was 0.12% (dry weight basis). Table 7 compares the absorbance and eluted phosphorus concentration when the salt concentration and heat treatment are changed, and Table 8 compares them when the hydrochloric acid concentration is changed, but no significant differences were found.

[0035] When using soybean meal as a feed ingredient, it is first autoclaved at 120°C for 10 minutes to inactivate the protease inhibitors, which are inherent protein digestion enzyme inhibitors. After pulverizing and treating with phytase, phosphorus can be efficiently removed in the subsequent washing process. Specifically, 1200g of soybean meal is mixed uniformly with 1500g of tap water containing 6g of phytase and 6g of citric acid. This mixture is placed in a plastic bag and left to stand at 45-50°C for 24 hours. After that, it is washed three times with 0.02N HCl and finally washed and dehydrated once with tap water. The phosphorus content of the soybean meal prepared by this process was 0.18% (dry weight basis). Tables 9 and 10 compare the total phosphorus content of soybean meal treated with phytase and that treated by other methods. It can be seen that the total phosphorus content is lower in the soybean meal treated with phytase, indicating a greater effect in reducing phosphorus.

[0036] Low-phosphorus feed may be prepared by mixing the washed raw materials mentioned above with other ingredients (wheat flour, canola oil, cod liver oil, vitamins, choline chloride, vitamin C, vitamin E, etc.), forming it into pellets, and drying it. Water may be added as needed during mixing.

[0037] [Table 1] + Absorbance at 680 nm of a solution obtained by coloring the supernatant after centrifugation with ammonium molybdate. *Per serving of chicken (wet weight)

[0038] [Table 2] Same as in the footnotes in Table 1. *Additives: 1g chicken liver, 0.1g saturated MgSO4 solution, 0.2g CaCO3. Chicken liver was added as an enzyme source to promote autodigestion, Mg was added to enhance enzyme activity, and CaCO3 was added to adjust the pH.

[0039] [Table 3] Same as in the footnotes in Table 1. ++ Per serving of chicken (wet weight) *Additives: 0.03g saturated MgSO4 aqueous solution, 0.15g lactic acid, 1g NaCl. The purpose of freezing and thawing is to break down cell membranes and promote enzyme activity, and lactic acid and NaCl were added to suppress spoilage during maturation.

[0040] [Table 4] Same as in the footnotes in Table 1. *Additives: Chicken liver 1g, MgSO4 saturated aqueous solution 0.1g, CaCO3 0.2g

[0041] [Table 5] *The volume of each extract is 10 mL, and extraction is performed by shaking for 15 minutes (at room temperature). + Absorbance at 440 nm of a solution obtained by coloring the supernatant after centrifugation with vanadomolybdic acid. ++ Per Feather Meal (dry weight basis)

[0042] [Table 6] *The volume of each extract is 5 mL, and extraction is performed by shaking for 15 minutes (at room temperature). Same as in the footnotes in Table 5. ++ Per Feather Meal (dry weight basis)

[0043] [Table 7] *The volume of each extract is 1 mL, and the extraction method is boiling. Same as in the footnotes in Table 5. ++ Per serving of blood powder (dry weight)

[0044] [Table 8] *The volume of each extract is 1 mL. + Same as in the footnote to Table 5. ++ Per serving of blood powder (dry weight)

[0045] [Table 9] *Autoclaved at 120°C for 10 minutes (in flake form) +Dry weight ratio

[0046] [Table 10] *After being autoclaved at 120°C for 10 minutes, it was ground into powder. +Dry weight ratio

[0047] [Fish farming methods] The fish farming method according to this embodiment includes replacing conventional aquaculture feed with the low-phosphorus aquaculture feed described above and feeding it to the fish.

[0048] By feeding the fish a low-phosphorus aquaculture feed, they become phosphorus-deficient. Similar to the embodiments described above, skeletal formation is inhibited, and the bones become softer. Furthermore, as mentioned above, the fish become fattier and their taste improves.

[0049] In Embodiment 2, it was preferred to feed the fish a diet containing a reduced substance in an amount greater than the amount required to react with ferric iron at a certain frequency. The low-phosphorus aquaculture diet described in this embodiment may be used as the diet containing a reduced substance in an amount greater than the amount required to react with ferric iron in Embodiment 2.

[0050] [Farmed fish] The farmed fish produced according to this embodiment suffer from phosphorus deficiency, leading to impaired skeletal formation and other problems.

[0051] The aquaculture feeds described in each embodiment may be used individually, or they may be combined as compound feeds as appropriate. Furthermore, the different aquaculture methods may be combined to form a complex aquaculture method.

[0052] [Examples] Next, a table showing the ash content (bone density) of fish farmed using the aquaculture feed of the present invention will be presented, and each example will be explained. Each example describes fish obtained by producing the disclosed aquaculture feed using the manufacturing method described in the above-described embodiment and farming them using the aquaculture method.

[0053] [Example 1] The fish farmed in Examples 1 to 5 is the Japanese minnow (Honmoroko). In each table, the bone weight is the weight of the defatted and dried vertebrae, and the ash weight is the weight after it has been reduced to ash in an electric furnace (550°C, 12 hours). The ash content is the ratio of the ash weight to the bone weight. These values ​​represent the results of analyzing fish actually farmed.

[0054] In the aquaculture feeds of Examples 1 to 5, fish were fed a feed containing 60% fish meal, 30% wheat flour, 1% vitamins, 1% calcium hydroxide, 3% calcium carbonate, and 5% of the additives shown in the table. Per 1 kg of the aquaculture feed, the following vitamins were used: 5 mg of thiamine nitrate, 20 mg of riboflavin, 50 mg of niacin, 50 mg of calcium pantothenate, 15 mg of pyridoxine hydrochloride, 5 mg of folic acid, 0.05 mg of vitamin B12, 0.5 mg of D-biotin, 300 mg of inositol, 2000 mg of ascorbic acid, 10000 mg of cod liver oil, 1000 mg of α-tocopherol acetate, 20 mg of sodium menadione sulfonate, and 6.53445 g of corn starch as an excipient. The cultivation period is 44 days, during which the water temperature is 23-25°C.

[0055] In the aquaculture feed of this Example 1, FeCl3 was added as a substance to insolubilize phosphorus. Table 11 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 42.98%. In addition, low levels of rib deformation were observed in 4 individuals and moderate levels of rib deformation in 4 individuals. [Table 11]

[0056] [Example 2] In the aquaculture feed of this Example 2, Fe2C(SO4)3 was added as a substance to insolubilize phosphorus. Table 12 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 43.06%. In addition, low levels of rib deformation were observed in 7 individuals and moderate levels of rib deformation in 1 individual among the 8 individuals. [Table 12]

[0057] [Example 3] In the aquaculture feed of this Example 3, FeC6H5O7 was added as a substance to insolubilize phosphorus. Table 13 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 45.64%. In addition, low levels of rib deformation were observed in 3 of the 8 individuals. [Table 13]

[0058] [Example 4] In the aquaculture feed of this Example 4, Al2(SO4)3 was added as a substance to insolubilize phosphorus. Table 14 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 36.87%. Of the 8 individuals, low-level rib deformation was observed in 3 individuals, medium-level rib deformation in 4 individuals, and high-level rib deformation in 1 individual. [Table 14]

[0059] [Example 5] In the aquaculture feed of this Example 5, AlK(SO4)2 was added as a substance to insolubilize phosphorus. Table 15 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 37.30%. Among the 8 individuals, low-level rib deformation was observed in 1 individual, medium-level rib deformation in 5 individuals, and high-level rib deformation in 1 individual. [Table 15]

[0060] From the results above, it can be said that when fish are farmed using commercially available feed, the ash content is usually 50% or more. Therefore, feeding them aquaculture feed containing ferric salts and aluminum salts will lower the ash content (bone density). Furthermore, the observation of bone deformation due to the decrease in bone density indicates that the fish have softer bones and are easier to eat.

[0061] [Example 6] The fish farmed in Examples 6 and 7 is the Japanese minnow (Honmoroko). The aquaculture feed in Example 6 contains washed chicken meat as a phosphorus-reduced ingredient.

[0062] The feed contains washed chicken meat, wheat flour, canola oil, cod liver oil, vitamins, choline chloride, vitamin C, and vitamin E. The washed chicken meat weighs 142g wet (43.9g dry), wheat flour 17.6g, canola oil 8.8g, cod liver oil 0.88g, vitamins 1.32g, choline 43.9mg, vitamin C 87.9mg, and vitamin E 87.9mg. In Table 17, the chicken meat (unwashed) weighs 260g wet (65.0g dry), wheat flour 26.0g, canola oil 13.0g, cod liver oil 1.30g, vitamins 1.95g, choline chloride 65.0mg, vitamin C 130.0mg, and vitamin E 130.0mg. The vitamins used are the same as in Example 1. The cultivation period was 18 days, and the water temperature was 23-25°C. Table 16 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 31.96%. In addition, low levels of rib deformation were observed in 7 of the 8 individuals.

[0063] [Table 16]

[0064] [Example 7] In the aquaculture feed of this Example 7, unwashed chicken meat is used as the raw material, and FeCl3 is added as a substance to insolubilize phosphorus. The feed also contains wheat flour, canola oil, cod liver oil, vitamins, choline chloride, vitamin C, and vitamin E, similar to Example 6. Table 17 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 38.73%. In addition, low levels of rib deformation were observed in 3 individuals and moderate levels of rib deformation in 5 individuals. [Table 17]

[0065] As shown in Examples 6 and 7, both the washed chicken meat and the feed to which FeCl3 was added to the chicken meat had low ash content, and bone deformation was also observed.

[0066] In Examples 8 to 12, the fish fed with the aquaculture feed were rainbow trout. The bone weight, ash weight, and ash content in each table are the same as in the above-mentioned examples. The components of the feed are the same as in Examples 1 to 5, except that the wheat flour has been changed to 25% and the calcium carbonate to 8%. The cultivation period was 43 days, and the water temperature was 16-18°C.

[0067] [Example 8] In the aquaculture feed of this Example 8, FeCl3 was added as a substance to insolubilize phosphorus. Table 18 shows the results of measuring the ash content of four farmed fish individuals fed this feed, with the average ash content being 43.40%. Furthermore, no rib deformation was observed in any of the four individuals. [Table 18]

[0068] [Example 9] In the aquaculture feed of this Example 9, Fe2(SO4)3 was added as a substance to insolubilize phosphorus. Table 19 shows the results of measuring the ash content of 7 farmed fish individuals fed this feed, with the average ash content being 44.87%. Furthermore, no rib deformation was observed among the 7 individuals. [Table 19]

[0069] [Example 10] In the aquaculture feed of this Example 10, FeC6H5O7 was added as a substance to insolubilize phosphorus. Table 20 shows the results of measuring the ash content of two farmed fish individuals fed this feed, with the average ash content being 43.33%. In addition, a low level of rib deformation was observed in one of the two individuals. [Table 20]

[0070] [Example 11] In the aquaculture feed of this Example 11, Al2(SO4)3 was added as a substance to insolubilize phosphorus. Table 21 shows the results of measuring the ash content of 7 farmed fish individuals fed this feed, with the average ash content being 33.90%. In addition, low levels of rib deformation were observed in 2 individuals and moderate levels of rib deformation in 3 individuals. [Table 21]

[0071] [Example 12] In the aquaculture feed of this Example 12, AlK(SO4)2 was added as a substance to insolubilize phosphorus. Table 22 shows the results of measuring the ash content of 5 farmed fish individuals fed this feed, with the average ash content being 34.29%. In addition, low levels of rib deformation were observed in 2 of the 5 individuals. [Table 22]

[0072] [Comparative Example 1] For comparison, rainbow trout were fed commercially available aquaculture feed under the same conditions as in Examples 8 to 12. The commercially available aquaculture feed was "Masu Next," a compound feed for trout rearing manufactured by Feed One Co., Ltd. The guaranteed components are crude protein 45% or more, crude fat 4.0% or more, crude fiber 4.0% or less, crude ash 13.0% or less, calcium 1.5% or more, and phosphorus 1.0% or more. The raw materials used were fish meal 45%, wheat flour 25%, soybean oil cake / corn gluten meal 24%, rice bran 2%, and other 4%. Table 23 shows the results of measuring the ash content, etc., of 7 farmed fish individuals fed this commercially available aquaculture feed, and the average ash content was 49.53%. In addition, no rib deformation was observed among the 7 individuals. [Table 23]

[0073] Comparing Examples 8 to 12 with Comparative Example 1, it was found that the ash content in Examples 8 to 12 was approximately 4-15% lower, and deformation of the fish bones was observed.

[0074] In Examples 13 to 18, the fish fed with the aquaculture feed were Japanese minnows (Honmoroko). Here, several types of phosphorus-insolubilizing substances were added to the aquaculture feed. The bone weight, ash weight, and ash content in each table are the same as in the above-mentioned examples. The aquaculture feed consisted of a mixture of 62% soybean oil cake, 10% blood meal, 10% feather meal, 10% corn gluten, 1% carboxymethylcellulose sodium, 1% vitamins, and 6% of the additives shown in the table.

[0075] The 6% of additives were as follows: Example 13: Ca(OH)2 2%, FeCl3·6H2O 4%, Example 14: CaCO3 1%, Ca(OH)2 2%, AlK(SO4)2·12H2O 3%, Example 15: CaCO3 2%, Ca(OH)2 2%, Al2(SO4)3·16H2O 2%, Example 16: Ca(OH)2 2%, FeCl3·6H2O 3%, Al2(SO4)3·16H2O 1%, Example 17: Ca(OH)2 2%, FeCl3·6H2O 4%, Example 18: CaCO3 2%, Ca(OH)2 2%, Al2(SO4)3·16H2O 2%.

[0076] Each 1 kg of aquaculture feed contains the following vitamins: thiamine nitrate 5 mg, riboflavin 20 mg, niacin 50 mg, calcium pantothenate 50 mg, pyridoxine hydrochloride 15 mg, folic acid 5 mg, vitamin B12 0.05 mg, D-biotin 0.5 mg, inositol 300 mg, menadione sulfonate sodium 20 mg, and corn starch 9.534 g as an excipient. The cultivation period is 41 days, and the water temperature is 23-25°C.

[0077] In Examples 13 to 18, the fish were fed a feed once a week consisting of 30% soybean oil meal, 10% blood meal, 10% feather meal, 10% corn gluten, 15% wheat flour, 5% cod liver oil, 5% canola oil, 1% vitamins, and 5% of a mixture of CaCO3 and Ca(OH)2 in a 3:2 ratio. Each 1 kg of aquaculture feed contains the following vitamins: thiamine nitrate 5 mg, riboflavin 20 mg, niacin 50 mg, calcium pantothenate 50 mg, pyridoxine hydrochloride 15 mg, folic acid 5 mg, vitamin B12 0.05 mg, D-biotin 0.5 mg, choline chloride 500 mg, inositol 500 mg, ascorbic acid 2000 mg, α-tocopherol acetate 1000 mg, sodium menadione sulfonate 30 mg, antioxidants 150 mg, and corn starch 5.624 g as an excipient.

[0078] [Example 13] In the aquaculture feed of this Example 13, FeCl3 and Ca(OH)2 were added as substances to insolubilize phosphorus. Table 24 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 39.63%. In addition, low-level rib deformation was observed in 1 individual and moderate-level rib deformation in 3 individuals among the 8 individuals. [Table 24]

[0079] [Example 14] In the aquaculture feed of this Example 14, AlK(SO4)2 and Ca(OH)2 were added as substances to insolubilize phosphorus. Table 25 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 40.36%. In addition, low levels of rib deformation were observed in 2 individuals and moderate levels of rib deformation in 5 individuals. [Table 25]

[0080] [Example 15] In the aquaculture feed of this Example 15, Al2(SO4)3 and Ca(OH)2 were added as substances to insolubilize phosphorus. Table 26 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 38.89%. In addition, low levels of rib deformation were observed in 5 individuals and moderate levels of rib deformation in 2 individuals. [Table 26]

[0081] [Example 16] In the aquaculture feed of this Example 16, FeCl3, Ca(OH)2, and Al2(SO4)3 were added as substances to insolubilize phosphorus. Table 27 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 39.46%. In addition, low levels of rib deformation were observed in 4 individuals and moderate levels of rib deformation in 3 individuals. [Table 27]

[0082] [Example 17] In the aquaculture feed of this Example 17, FeCl3 and Ca(OH)2 were added as substances to insolubilize phosphorus. Table 28 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 42.20%. In addition, low levels of rib deformation were observed in 4 individuals and moderate levels of rib deformation in 3 individuals. [Table 28]

[0083] [Example 18] In the aquaculture feed of this Example 18, Al2(SO4)3 and Ca(OH)2 were added as substances to insolubilize phosphorus. Table 29 shows the results of measuring the ash content of 8 farmed fish individuals fed this feed, with the average ash content being 40.36%. In addition, low levels of rib deformation were observed in 4 individuals and moderate levels of rib deformation in 4 individuals. [Table 29]

[0084] [Comparative Example 2] For comparison, Honmoroko fish were fed commercially available aquaculture feed under the same conditions as in Examples 13 to 18. The commercially available aquaculture feed was "Hikari Daily" koi carp feed from Kyorin Co., Ltd., with guaranteed components of 28% or more protein, 3.0% or more fat, 4.0% or less crude fiber, 10% or less moisture, 8.0% or less ash, and 0.5% or more phosphorus. The raw materials used were wheat flour, soybean meal, gluten meal, fish meal, rice bran, concentrated alfalfa, silkworm meal, seaweed powder, vitamins (choline chloride, E, C, B5, B2, A, B1, B6, B3, folic acid, D3, biotin), and minerals (P, Fe, Mg, Zn, Mn, Cu, I). Table 30 shows the results of measuring the ash content, etc., of 7 farmed fish individuals fed this commercially available aquaculture feed, with the average ash content being 51.61%. Furthermore, no rib deformities were observed in any of the eight individuals. [Table 30]

[0085] Comparing the ash content of Examples 13 to 18 with that of Comparative Example 2, it can be seen that the ash content of Examples 13 to 18 is about 9-13% lower than that of Comparative Example 2, indicating that bone deformation occurred in fish fed with the aquaculture feed of the present invention. In other words, the aquaculture feed of the present invention, which contains multiple additives, makes bone formation less likely compared to commercially available products, resulting in softer bones that are easier to eat whole.

[0086] Figure 1 shows the bones of a Honmoroko fish fed with aquaculture feed supplemented with aluminum salt (Al2(SO4)3). Figure 2 shows photographs of the bones of a Honmoroko fish fed with aquaculture feed containing washed chicken meat and a Honmoroko fish fed with commercially available aquaculture feed. Figure 3 shows magnified photographs of the ribs of a Honmoroko fish fed with aquaculture feed supplemented with chicken meat and FeCl3 and a Honmoroko fish fed with commercially available aquaculture feed. In all cases, the bones of the Honmoroko fish fed with the aquaculture feed of this invention were either not formed or were deformed due to low bone density.

[0087] [Reference example 1] As Reference Example 1, we present an example in which the fat, EPA, and DHA levels of farmed fish increased when using a low-phosphorus feed. The fish farmed in this reference example is crucian carp. The feed used in this reference example is prepared using wheat gluten (38%), dried egg white (5%), soybean meal (10%), fish oil (20%), and wheat flour (22%) as the main ingredients. Table 31 shows the results of an analysis of crucian carp farmed at 27°C for 61 days on this feed.

[0088] [Table 31]

[0089] [Comparative Example 3] As Comparative Example 3 to Reference Example 1, Table 32 shows the results of analyzing crucian carp that were similarly farmed using a feed prepared by adding 4% monosodium phosphate to the low-phosphorus feed of Reference Example 1. [Table 32]

[0090] Both the fish fed with the feeds in Reference Example 1 and Comparative Example 3 were crucian carp with an average weight of 4g. Compared to the crucian carp farmed using the high-phosphorus feed in Comparative Example 3, the crucian carp farmed using the low-phosphorus feed in Reference Example 1 showed an increase in fat content, as well as an increase in fat-soluble functional components such as EPA and DHA. This is expected to have various ripple effects, including the prevention of lifestyle-related diseases and dementia, brain development (in infants and young children), and more.

[0091] Although the present invention has been described above, it can be implemented in various forms with improvements, modifications, and changes based on the knowledge of those skilled in the art, without departing from its spirit.

Claims

1. Fish farming feed, At least one of plant-based or animal-based materials, Substances that inhibit phosphorus absorption, Includes, The aforementioned plant material contains phytic phosphorus and inorganic phosphoric acid. The aforementioned animal raw material comprises hydroxyapatite, phosphoprotein, and inorganic phosphoric acid. The substance that inhibits the absorption of phosphorus is Calcium hydroxide reacts with the phytic phosphorus to make it insoluble. An aluminum salt or ferric salt that reacts with the inorganic phosphoric acid to insolubilize phosphorus, Calcium hydroxide, a calcium salt, or both, which react with the hydroxyapatite to insolubilize phosphorus. Aluminum salt or ferric salt that binds to the phosphoprotein, including at least one of the Aquaculture feed.

2. The aquaculture feed according to claim 1, wherein, when the aquaculture feed contains ferric salts, the total amount of reducing substances contained in the aquaculture feed is less than the equivalent amount required to reduce the total amount of ferric salts.

3. The aquaculture feed according to claim 1 or 2, wherein, when the aquaculture feed contains an aluminum salt, the aluminum salt is present in an amount of 0.01 to 2% of the total weight of the aquaculture feed.

4. The aquaculture feed according to claim 1 or 2, wherein, when the aquaculture feed contains both calcium hydroxide and calcium salt, the calcium hydroxide and calcium salt are present in an amount of 1 to 8% of the total weight of the aquaculture feed.

5. A method for producing feed for fish farming, A process of preparing raw materials containing plant materials, animal materials, or both, The process of crushing and stirring the raw materials, A step of adding a substance that inhibits phosphorus absorption to the raw material, Equipped with, The aforementioned plant material contains phytic phosphorus and inorganic phosphoric acid. The aforementioned animal raw material comprises hydroxyapatite, phosphoprotein, and inorganic phosphoric acid. The substance that inhibits the absorption of phosphorus is Calcium hydroxide reacts with the phytic phosphorus to make it insoluble. An aluminum salt or ferric salt that reacts with the inorganic phosphoric acid to insolubilize phosphorus, Calcium hydroxide, a calcium salt, or both, which react with the hydroxyapatite to insolubilize phosphorus. Aluminum salt or ferric salt that binds to the phosphoprotein, including at least one of the A method for producing feed for fish farming.

6. The method for producing aquaculture feed according to claim 5, wherein, when the aquaculture feed contains ferric salts, the total amount of reducing substances contained in the aquaculture feed is less than the equivalent amount required to reduce the total amount of ferric salts.

7. The method for producing aquaculture feed according to claim 5 or 6, wherein, when the aquaculture feed contains an aluminum salt, the aluminum salt is contained in an amount of 0.01 to 2% of the total weight of the aquaculture feed.

8. The method for producing aquaculture feed according to claim 5 or 6, wherein, when the aquaculture feed contains both calcium hydroxide and calcium salt, the calcium hydroxide and calcium salt are present in an amount of 1 to 8% of the total weight of the aquaculture feed.

9. A method of fish farming, A method for farming fish, characterized by comprising the step of feeding the fish with the fish feed described in claim 1 or the fish feed produced by the manufacturing method described in claim 5.

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