A method for producing compound feed for salmon farming using Schizochytrium strains, a nutrient-rich microalgae

Abstract

The feed composition containing the microalgae-derived biomass of the present application does not cause any factors that reduce the quality of the feed, and can be usefully used in fish feed compositions using microalgae that are high in protein, fat, and minerals.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0027303, filed on February 28, 2023, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] The present application relates to a feed composition for salmonid fish containing biomass derived from microalgae and a method for producing the same. [Background technology]

[0003] Global population growth and the resulting slowdown and continued decline in grain and fishery production continue to raise concerns about future food security, and many scientists believe that the aquaculture industry holds the sole potential to resolve these food issues. Global farmed fish production rose from 2.4 million tons half a century ago to 87.5 million tons in 2020, accounting for 49% of total seafood production. Among these farmed fish, marine fish and crustacean feed consumption is growing rapidly (FAO 2022), and this growth trend is expected to continue. Today, fish feed nutrition is one of several key factors for the success of the aquaculture industry. It is well-known that once key fish species are prioritized for cultivation and seed production techniques are developed, they must be managed with high-quality feed. The importance of feed nutrition is particularly evident, as feed costs account for 30-60% of the unit cost of aquaculture production, although this varies by fish species.

[0004] Feed utilization varies depending on the protein source. Fish meal is made by drying and grinding the fish meal and other fish waste left over after the fish oil is extracted from fish. It has long been used as the primary protein source in fish feed due to its high protein content, excellent amino acid composition, and high palatability. However, a recent sharp decline in production has led to unstable supplies and skyrocketing prices, making fish meal the largest component of feed purchasing costs. The catch volume of various small fish used to produce fish meal has declined sharply due to overfishing and marine environmental issues, and production is predicted to continue declining through 2030. For these reasons, extensive research is underway to find affordable, high-quality protein sources that can replace fish meal in fish feed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US 2015-0208696 A1 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present application is to provide a feed composition for salmonid fish comprising biomass derived from microalgae.

[0007] Another object of the present application is to provide a method for producing said feed composition.

[0008] Another object of the present application is to provide a method for cultivating salmonid fish, comprising the step of feeding said feed composition to salmonid fish. [Means for solving the problem]

[0009] One embodiment provides a feed composition for salmonid fish comprising a biomass derived from microalgae; or a use of a biomass derived from microalgae or a feed composition for salmonid fish comprising the biomass derived from said microalgae for enhancing digestibility in salmonid fish; or a composition for enhancing digestibility in salmonid fish comprising a biomass derived from microalgae or a feed composition for salmonid fish comprising the biomass derived from said microalgae.

[0010] Biomass derived from microalgae Herein, the microalgae may be Schizochytrium microalgae.

[0011] In this specification, "microalgae" refers to plants that perform photosynthesis using chlorophyll and cannot be easily seen with the naked eye, but can be seen through a microscope, and refers to organisms that live freely floating in water, and are also called phytoplankton.

[0012] As used herein, microalgae of the genus Schizochytrium are microorganisms belonging to the family Thraustochytriaceae, and may be one or more species selected from the group consisting of Schizochytrium aggregatum, Schizochytrium limacinum, Schizochytrium minutum, etc., but are not limited thereto.

[0013] In one example, the Schizochytrium microalgae may be Schizochytrium aggregatum.

[0014] In one example, the Schizochytrium microalgae may be Schizochytrium limacinum.

[0015] In one example, the Schizochytrium microalgae may be Schizochytrium minutum.

[0016] In one example, the microalgae of the genus Schizochytrium may be Schizochytrium sp. CD01-5004 deposited under the accession number KCTC14345BP.

[0017] As used herein, biomass refers to living organisms such as plants, animals, and microorganisms that can be used as chemical energy, i.e., a source of bioenergy. It can also refer to the weight or amount of energy of a specific organism present within a unit of time and space ecologically. Biomass includes, but is not limited to, compounds secreted by cells, and may contain not only extracellular substances but also cells and / or intracellular contents.

[0018] As used herein, the microalgae-derived biomass may be, but is not limited to, the microalgae itself, a culture thereof, a fermented product thereof, a dried product thereof, or a crushed product thereof, or a product produced by culturing or fermenting the microalgae, or a concentrated or dried product of the biomass. That is, the microalgae-derived biomass may include one or more selected from the group consisting of microalgae, a culture of the microalgae, a dried product of the culture, and a crushed product of the dried product.

[0019] The "culture" of the microalgae refers to a product produced by culturing the microalgae, and specifically may be, but is not limited to, a culture solution containing the microalgae or a culture filtrate obtained by removing the microalgae from the culture solution. The "dried product" of the microalgae culture refers to the microalgae culture from which water has been removed, and may be, for example, in the form of dried cells of the microalgae, but is not limited to this. Furthermore, the "crushed product" of the dried product collectively refers to the product obtained by crushing the dried product from which water has been removed from the microalgae culture, and may be, for example, a dried cell powder, but is not limited to this. The microalgae culture may be produced by inoculating the microalgae into a microalgae culture medium and using a culture method known in the art, or by using a dried product of the culture and its crushed product, or by a method for treating or drying microalgae or the culture solution known in the art.

[0020] The microalgae-derived biomass is rich in nutrients such as proteins, fats, amino acids, fatty acids, and minerals such as phosphorus, iron, copper, manganese, zinc, etc., and can be usefully used in feed compositions. In particular, the microalgae-derived biomass has a high content of essential amino acids for fish and a high content of high-quality protein raw materials, and can therefore be usefully used in fish feed compositions where protein accounts for a high proportion in the feed.

[0021] The amino acids may include proteinogenic amino acids such as arginine, histidine, lysine, aspartic acid, glutamic acid, serine, threonine, asparagine, glutamine, cysteine, glycine, proline, alanine, valine, isoleucine, leucine, methionine, phenylalanine, tylosin, and tryptophan; and non-proteinogenic amino acids such as hydroxyproline, ornithine, and cysteine / cystine.

[0022] As used herein, "essential amino acids" generally refer to amino acids that cannot be synthesized from precursors in the body of an organism, and in the case of fish, essential amino acids may include isoleucine, leucine, valine, threonine, methionine, tryptophan, phenylalanine, alanine, arginine, and lysine. The feed composition of the present application contains large amounts of essential amino acids that are deficient in fish, and can therefore effectively supply the essential amino acids that are deficient in fish.

[0023] As used herein, ash may refer to ash generated by burning a sample or the total amount of inorganic substances contained in a sample. Ash may be used interchangeably with terms such as minerals, inorganic substances, inorganic salts, and mineral matter, and may include one or more inorganic elements selected from the group consisting of calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium, iron, copper, manganese, iodine, cobalt, zinc, molybdenum, selenium, chromium, fluorine, boron, arsenic, tin, silicon, vanadium, and nickel.

[0024] As used herein, fatty acids are carboxylic acids containing 4 to 36 carbon atoms (e.g., 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, etc.) as a constituent of fat, and may refer to saturated fatty acids with no double bonds between carbon atoms or unsaturated fatty acids with double bonds. The unsaturated fatty acids may be trans-unsaturated fatty acids or cis-unsaturated fatty acids depending on the arrangement of the double bonds, and may be monounsaturated fatty acids or polyunsaturated fatty acids depending on the number of double bonds.

[0025] As is widely known in the art, the fatty acids can be represented by common names, IUPAC nomenclature, delta-x nomenclature, nx nomenclature (or omega-x nomenclature), lipid number nomenclature (C:D, where C is the number of carbon atoms in the fatty acid and D is the number of double bonds in the fatty acid), etc.

[0026] In one example, the saturated fatty acid is caprylic acid (octanoic acid, C8:0), decanoic acid (decanoic acid, C10:0), lauric acid (dodecanoic acid, C12:0), myristic acid (tetradecanoic acid, C14:0), palmitic acid (hexadecanoic acid, C16:0), stearic acid (octadecanoic acid, C18:0), arachidic acid (icosanoic acid, C20:0), behenic acid (docosanoic acid, C22:0), lignoceric acid (tetracosanoic acid, C24:0), cerotic acid (hexacosanoic acid, C25:0), hydroxybenzoic acid (hydroxybenzoic acid, C26:0), hydroxybenzoic acid (hydroxybenzoic acid, C27:0), hydroxybenzoic acid (hydroxybenzoic acid, C28:0), hydroxybenzoic acid (hydroxybenzoic acid, C29:0), hydroxybenzoic acid (hydroxybenzoic acid, C30:0), hydroxybenzoic acid (hydroxybenzoic acid, C31:0), hydroxybenzoic acid (hydroxybenzoic acid, C32:0), hydroxybenzoic acid (hydroxybenzoic acid, C33:0), hydroxybenzoic acid (hydroxybenzoic acid, C34:0), hydroxybenzoic acid (hydroxybenzoic acid, C35:0), hydroxybenzoic acid (hydroxybenzoic acid, C36:0), hydroxybenzoic acid (hydroxybenzoic acid, C37:0), hydroxybenzoic acid (hydroxybenzoic acid, C38:0), hydroxybenzoic acid (hydroxybenzoic acid, C39:0), hydroxybenzoic acid (hydroxybenzoic acid, C39:0), hydroxybenzoic acid (hydroxybenzoic acid, C39:0), hydroxybenzoic acid (hydroxybenzoic acid, C38:0), hydroxybenzoic acid (hydroxybenzoic acid, C39:0), hydroxybenzoic acid (hydroxybenzoic acid, C39:0), hydroxy The alkyl group may be, but is not limited to, alkyl groups such as aryl groups, alkyl ester ...

[0027] Preface: Unsaturated fatty acids include Myristoleic acid (9Z)-Tetradec-9-enoic acid, C14:1 n-5), Palmitoleic acid (9Z)-Hexadec-9-enoic acid, C16:1 n-7), Sapienic acid (6Z)-Hexadec-6-enoic acid, C16:1 n-10), Oleinic acid (9Z)-Octadec-9-enoic acid, C18:1 n-9), Elaidic acid (E)-octadec-9-enoic acid, C18:1 n-9), and Vaccenic acid. acid, (11E)-Octadeca-11-enoic acid, C18:1 n-7), Linoleic acid, (9Z,12Z)-Octadeca-9,12-dienoic acid, C18:2 n-6), Linoleelaidic acid acid, (9E,12E)-Octadeca-9,12-dienoic acid, C18:2 n-6), alpha-Linolenic acid, (9Z,12Z,15Z)-Octadeca-9,12,15-trienoic acid, C18:3 n-3), Stearidonic acid, (6Z,9Z,12Z,15Z)-Octadeca-6,9,12,15-tetraenoic (C18:4 n-3), Arachidonic acid ((5Z,8Z,11Z,14Z)-Icosa-5,8,11,14-tetraenoic acid, C20:4 n-6), Eicosatetraenoic acid (icosa-8,11,14,17-tetraenoic acid, C20:4 n-3), Eicosapentaenoic acid ((5Z,8Z,11Z,14Z,17Z)-Icosa-5,8,11,14,17-pentaenoic acid, C20:5 ...6), Eicosatetraenoic acid (icosa-8,11,14,17-tetraenoic acid, C20:4 n-3), Eicosatetraenoic acid (icosa-8,11,14,17-tetraenoic acid, C20:4 n-6), Eicosatetraenoic acid (icosa-8,11,14,17-tetraenoic acid, C20:5 n-6), E n-3), Heneicosapentaenoic acid, (6Z, 9Z, 12Z, 15Z,(18Z)-henicosa-6,9,12,15,18-pentaenoic acid, C21:5 n-3), cetoleic acid ((Z)-docos-11-enoic acid, C22:1 n-11), erucic acid ((13Z)-Docos-13-enoic acid, C22:1 n-9), 15-docosenoic acid ((E)-docos-15-enoic acid, C22:1 n-7), docosapentaenoic acid ((7Z,10Z,13Z,16Z,19Z)-Docosa-7,10,13,16,19-pentaenoic acid, C22:5 n-3), docosahexaenoic acid Examples of suitable carboxylic acids include, but are not limited to, (4Z,7Z,10Z,13Z,16Z,19Z)-Docosa-4,7,10,13,16,19-hexaenoic acid, C22:6 n-3, and Nervonic acid ((Z)-Tetracos-15-enoic acid, C24:1 n-9).

[0028] The unsaturated fatty acid may be an omega-3 fatty acid, an omega-6 fatty acid, an omega-7 fatty acid, or an omega-9 fatty acid, and the omega-3 fatty acid, the omega-6 fatty acid, the omega-7 fatty acid, or the omega-9 fatty acid may be, but is not limited to, those exemplified in Table 1 below.

[0029] [Table 1] JPEG2026506803000003.jpg172149

[0030] The microalgae-derived biomass contains protein (e.g., crude protein) at 50% by weight or more, 51% by weight or more, 52% by weight or more, 53% by weight or more, 54% by weight or more, 55% by weight or more, 56% by weight or more, 57% by weight or more, 58% by weight or more, 59% by weight or more, 60% by weight or more, 61% by weight or more, 62% by weight or more, 63% by weight or more, 64% by weight or more, 65% by weight or more, 66% by weight or more, 67% by weight or more, 68% by weight or more, 69% by weight or more, 70% by weight or more, 71% by weight or more, 72% by weight or more, 73% by weight or more, 74% by weight or more, 75% by weight or more, 50 to 100% by weight % by weight, 50-98% by weight, 50-95% by weight, 50-92% by weight, 50-90% by weight, 50-88% by weight, 50-85% by weight %, 50-82% by weight, 50-80% by weight, 50-78% by weight, 50-75% by weight, 50-74% by weight, 52-100% by weight, 52-98% by weight, 52-95% by weight, 52-92% by weight, 52-90% by weight, 52-88% by weight, 52-85% by weight, 52 52-82% by weight, 52-78% by weight, 52-75% by weight, 52-74% by weight, 55-100% by weight, 55-78% by weight 98% by weight, 55-95% by weight, 55-92% by weight, 55-90% by weight, 55-88% by weight, 55-85% by weight, 55-82 % by weight, 55-80% by weight, 55-78% by weight, 55-75% by weight, 55-74% by weight, 57-100% by weight, 57-98% by weight %, 57-95% by weight, 57-92% by weight, 57-90% by weight, 57-88% by weight, 57-85% by weight, 57-82% by weight, 57-80% by weight, 57-78% by weight, 57-75% by weight, 57-74% by weight, 60-100% by weight, 60-98% by weight, 60 60 to 95% by weight, 60 to 90% by weight, 60 to 88% by weight, 60 to 85% by weight, 60 to 82% by weight, 60 to 95% by weight 80% by weight, 60-78% by weight, 60-75% by weight, 60-74% by weight, 62-100% by weight, 62-98% by weight, 62-95 % by weight, 62-92% by weight, 62-90% by weight, 62-88% by weight, 62-85% by weight, 62-82% by weight, 62-80% by weight %, 62 to 78% by weight, 62 to 75% by weight, 62 to 74% by weight, 63 to 100% by weight, 63 to 98% by weight, 63 to 95% by weight,63-92% by weight, 63-90% by weight, 63-88% by weight, 63-85% by weight, 63-82% by weight, 63 63 to 78 weight%, 63 to 75 weight%, 63 to 74 weight%, 64 to 100 weight%, 64 to 80 weight% 98% by weight, 64-95% by weight, 64-92% by weight, 64-90% by weight, 64-88% by weight, 64-85% by weight, 64-82% by weight, 64-80% by weight, 64-78% by weight, 64-75% by weight, 64-74% by weight, 65-100% by weight, 65-98% by weight, 65-95% by weight, 65-92% by weight, 65-90% by weight, 65 65-85% by weight, 65-82% by weight, 65-80% by weight, 65-78% by weight, 65-7 5% by weight, 65-74% by weight, 66-100% by weight, 66-98% by weight, 66-95% by weight, 66-92% by weight, 66-90% by weight, 66-88% by weight, 66-85% by weight, 66-82% by weight, 66-80% by weight, 66-78% by weight, 66-75% by weight, 66-74% by weight, 66-100% by weight, 66-98% by weight, 6 6 to 95% by weight, 66 to 92% by weight, 66 to 90% by weight, 66 to 88% by weight, 66 to 85% by weight, 66 to 92% by weight 82% by weight, 66-80% by weight, 66-78% by weight, 66-75% by weight, 66-74% by weight, 68-100% by weight, 68-98% by weight, 68-95% by weight, 68-92% by weight, 68-90% by weight, 68-88% by weight The content may be, but is not limited to, 68 to 85% by weight, 68 to 82% by weight, 68 to 80% by weight, 68 to 78% by weight, 68 to 75% by weight, 68 to 74% by weight, 70 to 100% by weight, 70 to 98% by weight, 70 to 95% by weight, 70 to 92% by weight, 70 to 90% by weight, 70 to 88% by weight, 70 to 85% by weight, 70 to 82% by weight, 70 to 80% by weight, 70 to 78% by weight, 70 to 75% by weight, or 70 to 74% by weight.

[0031] The microalgae-derived biomass may contain ash at a content of 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, 2 to 20 wt%, 2 to 15 wt%, 2 to 10 wt%, 3 to 20 wt%, 3 to 15 wt%, 3 to 10 wt%, 4 to 20 wt%, 4 to 15 wt%, 4 to 10 wt%, 5 to 20 wt%, 5 to 15 wt%, 5 to 10 wt%, 6 to 20 wt%, 6 to 15 wt%, 6 to 10 wt%, 7 to 20 wt%, 7 to 15 wt%, or 7 to 10 wt%, but is not limited thereto.

[0032] The microalgae-derived biomass may contain moisture at a content of 1 to 10 wt%, 1 to 8 wt%, 1 to 6 wt%, 1 to 5 wt%, 2 to 10 wt%, 2 to 8 wt%, 2 to 6 wt%, 2 to 5 wt%, 3 to 10 wt%, 3 to 8 wt%, 3 to 6 wt%, or 3 to 5 wt%, but is not limited thereto.

[0033] The microalgae-derived biomass may contain fat at 1 to 20% by weight, 1 to 17% by weight, 1 to 15% by weight, 1 to 13% by weight, 2 to 20% by weight, 2 to 17% by weight, 2 to 15% by weight, 2 to 13% by weight, 3 to 20% by weight, 3 to 17% by weight, 3 to 15% by weight, 3 to 13% by weight, 4 to 20% by weight, 4 to 17% by weight, 4 to 15% by weight, 4 to 13% by weight, 5 to 20% by weight, 5 to 17% by weight, 5 to 15% by weight, 5 to 13% by weight, 6 to 20 ... %, 6 to 17 wt%, 6 to 15 wt%, 6 to 13 wt%, 7 to 20 wt%, 7 to 17 wt%, 7 to 15 wt%, 7 to 13 wt%, 8 to 20 wt%, 8 to 17 wt%, 8 to 15 wt%, 8 to 13 wt%, 9 to 20 wt%, 9 to 17 wt%, 9 to 15 wt%, 9 to 13 wt%, 10 to 20 wt%, 10 to 17 wt%, 10 to 15 wt%, or 10 to 13 wt%, but is not limited thereto.

[0034] The microalgae-derived biomass may contain phosphorus at a content of 0.1 to 2 wt%, 0.1 to 1.5 wt%, 0.1 to 1.0 wt%, 0.1 to 0.8 wt%, 0.2 to 2 wt%, 0.2 to 1.5 wt%, 0.2 to 1.0 wt%, 0.2 to 0.8 wt%, 0.3 to 2 wt%, 0.3 to 1.5 wt%, 0.3 to 1.0 wt%, or 0.3 to 0.8 wt%, but is not limited thereto.

[0035] The microalgae-derived biomass may contain saturated fatty acids in an amount of 10 parts by weight or more, 12 parts by weight or more, 15 parts by weight or more, 17 parts by weight or more, 20 parts by weight or more, 22 parts by weight or more, 25 parts by weight or more, 10 to 30 parts by weight, 10 to 28 parts by weight, 12 to 30 parts by weight, 12 to 28 parts by weight, 14 to 30 parts by weight, 14 to 28 parts by weight, 16 to 30 parts by weight, 16 to 28 parts by weight, 20 to 30 parts by weight, 20 to 28 parts by weight, 25 to 30 parts by weight, or 25 to 28 parts by weight, based on 100 parts by weight of lipids, but is not limited thereto.

[0036] The microalgae-derived biomass contains 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 10 to 50 parts by weight, 10 to 48 parts by weight, 10 to 45 parts by weight, 10 to 42 parts by weight, 10 to 40 parts by weight, 10 to 38 parts by weight, 10 to 35 parts by weight, 15 to 50 parts by weight, 15 to 48 parts by weight, 15 to 45 parts by weight, 15 to 42 ...2 parts by weight, 15 to 42 parts by weight, 15 to 50 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 42 parts by weight, 15 to 4 The amount of the hydroxybenzoate may be, but is not limited to, 40 parts by weight, 15 to 38 parts by weight, 15 to 35 parts by weight, 20 to 50 parts by weight, 20 to 48 parts by weight, 20 to 45 parts by weight, 20 to 42 parts by weight, 20 to 40 parts by weight, 20 to 38 parts by weight, 20 to 35 parts by weight, 25 to 50 parts by weight, 25 to 48 parts by weight, 25 to 45 parts by weight, 25 to 42 parts by weight, 25 to 40 parts by weight, 25 to 38 parts by weight, 25 to 35 parts by weight, 30 to 50 parts by weight, 30 to 48 parts by weight, 30 to 45 parts by weight, 30 to 42 parts by weight, 30 to 40 parts by weight, 30 to 38 parts by weight, or 30 to 35 parts by weight.

[0037] Feed composition As used herein, a feed composition may refer to a substance that provides nutrition to animals (including livestock, fish, etc.) or is necessary for their health maintenance or growth. The feed composition may be a simple feed, a compound feed, or a supplement. The simple feed may refer to a plant, animal, or mineral substance that is used directly in feed or used as an ingredient in compound feed. The supplement may refer to a substance added to feed to prevent deterioration in quality or to increase the efficacy of the feed. The compound feed may be a mixture or processed of simple feed, supplements, etc. in an appropriate ratio.

[0038] The feed composition may refer to a substance that provides organic or inorganic nutrients necessary for sustaining the life of an animal or producing meat, milk, etc. The feed composition may further include any suitable excipients commonly used in nutritional ingredients or feed compositions necessary for sustaining the life of an animal or producing meat, milk, etc. (e.g., preservatives, wetting agents, dispersing agents, suspending agents, buffers, stabilizers, or isotonicity agents), water, solvents, etc. The feed composition may be prepared in various forms known in the art, specifically, may include concentrated feed, roughage, and / or special feed. Alternatively, the feed composition may be prepared in the form of compound feed (extruded pellet, EP feed, dry feed) or raw feed (moist pellet, MP feed, wet feed), etc.

[0039] As used herein, the term "feed additive" refers to substances added to feed for various purposes, such as supplementing nutrients and preventing weight loss, increasing the digestibility of fiber in feed, improving milk quality, preventing reproductive disorders and improving conception rates, and preventing heat stress in summer. The term "feed additive" refers to a supplementary ingredient defined in the Feed Management Act, and may further include mineral preparations such as sodium bicarbonate, bentonite, magnesium oxide, and complex minerals, mineral preparations such as trace minerals like zinc, copper, cobalt, and selenium, vitamin preparations such as carotene, vitamin E, vitamins A, D, and E, nicotinic acid, and vitamin B complex, protected amino acids such as methionine and lysine, protected fatty acids such as fatty acid calcium salts, live bacteria preparations (lactic acid bacteria preparations), live bacteria such as yeast cultures and mold fermentation products, and yeast preparations.

[0040] The feed composition may further include grains such as crushed or crushed wheat, oats, barley, corn, and rice; vegetable protein feeds such as feeds mainly composed of beans and sunflower; animal protein feeds such as blood meal, meat meal, bone meal, and fish meal; dry ingredients such as sugars and dairy products such as various milk powders and whey powders; and may further include nutritional supplements, digestion and absorption enhancers, growth promoters, etc.

[0041] The feed composition can be administered to animals alone or in combination with other feed additives in an edible carrier. The feed composition can also be easily administered to animals as a top dressing, directly mixed with the feed, or in a separate oral dosage form. When administered separately from the feed, the composition can be combined with an edible carrier acceptable in the feed industry to produce an immediate-release or sustained-release dosage form, as is well known in the art. The edible carrier can be solid or liquid, such as corn starch, lactose, sucrose, pea flakes, peanut oil, olive oil, sesame oil, and propylene glycol. When a solid carrier is used, the feed composition can be in the form of a tablet, capsule, powder, lozenge, or top dressing in the form of a dragee or microdispersible tablet. When a liquid carrier is used, the feed composition can be in the form of a soft gelatin capsule, syrup, suspension, emulsion, or solution.

[0042] The feed composition may contain, for example, a preservative, a stabilizer, a humectant or emulsifier, a cryoprotectant, or an excipient. The cryoprotectant may be one or more selected from the group consisting of glycerol, trehalose, maltodextrin, skim milk powder, and starch. The preservative, stabilizer, or excipient may be contained in the feed composition in an amount effective enough to reduce deterioration of the microalgae contained in the composition. Furthermore, the cryoprotectant may be contained in the composition in an amount effective enough to reduce deterioration of the microalgae contained in the composition when the composition is in a dried state.

[0043] The feed composition may be added to animal feed by immersion, spraying or mixing.

[0044] The feed composition can be used in the diets of many animals, including, but not limited to, mammals, birds, fish, crustaceans, cephalopods, reptiles, and amphibians. For example, mammals can include pigs, cows, sheep, goats, laboratory rodents, and pets. Birds can include poultry, including, but not limited to, chickens, turkeys, ducks, geese, pheasants, and quails. Crustaceans can include, but are not limited to, shrimp and barnacles. The feed composition can also be used as a diet for rotifers, which are zooplankton. Fish can include freshwater fish, saltwater fish, commercially farmed fish and their fry, and ornamental fish.

[0045] In one example, the feed composition may be a salmonid feed composition.

[0046] As used herein, the term "fish of the family Salmonidae" refers to fish belonging to the order Salmoniformes, and may refer to one or more species of fish selected from the group consisting of the genus Coregonus, the genus Prosopium, the genus Stenodus, the genus Thymallus, the genus Salvelinus, the genus Oncorhynchus, the genus Brachymystax, the genus Hucho, the genus Parahucho, the genus Salmo, and the genus Salvethymus, but is not limited thereto.

[0047] In one example, the salmon species includes Chum salmon (Oncorhynchus keta), Coho salmon (Oncorhynchus kisutch), Sockeye salmon (Oncorhynchus nerka), Chinook salmon (Oncorhynchus tshawytscha), Pink salmon (Oncorhynchus gorbuscha), masu salmon (Oncorhynchus masou), Rainbow trout (Oncorhynchus mykiss), Cutthroat trout (Oncorhynchus clarkii), Golden trout (Oncorhynchus aguabonita), Apache trout (Oncorhynchus apache), Mexican golden trout (Oncorhynchus The fish may be one or more species selected from the group consisting of, but not limited to, Black trout (Oncorhynchus chrysogaster), Gila trout (Oncorhynchus gilae), Iwame trout (Oncorhynchus iwame), and Black kokanee (Oncorhynchus kawamurae).

[0048] The Atlantic salmon may be one or more species selected from the group consisting of Atlantic salmon (Salmo salar), brown trout (Salmo trutta), etc., but is not limited thereto.

[0049] The feed composition may be rich in nutrients such as proteins, fats, amino acids, fatty acids, and minerals such as phosphorus, iron, copper, manganese, zinc, etc. The nutrients are as described above.

[0050] The feed composition may contain 1 to 100% by weight, 1 to 95% by weight, 1 to 90% by weight, 1 to 85% by weight, 1 to 80% by weight, 1 to 75% by weight, 1 to 70% by weight, 1 to 65% by weight, 1 to 60% by weight, 1 to 55% by weight, 1 to 50% by weight, 1 to 45% by weight, 1 to 40% by weight, 1 to 35% by weight, 1 to 30% by weight, 5 to 100% by weight, 5 to 95% by weight, 5 to 90% by weight, 5 to 85% by weight, 5 to 80% by weight, 5 to 75% by weight, 5 to 70% by weight, 5 to 65% by weight, 5 to 60% by weight, 5 to 55% by weight , 5-50% by weight, 5-45% by weight, 5-40% by weight, 5-35% by weight, 5-30% by weight, 10-100% by weight, 10-9 5% by weight, 10 to 90% by weight, 10 to 85% by weight, 10 to 80% by weight, 10 to 75% by weight, 10 to 70% by weight, 10 to 65% by weight %, 10 to 60% by weight, 10 to 55% by weight, 10 to 50% by weight, 10 to 45% by weight, 10 to 40% by weight, 10 to 35% by weight, 10 to 30% by weight, 15 to 100% by weight, 15 to 95% by weight, 15 to 90% by weight, 15 to 85% by weight, 15 to 80% by weight, 15 15 to 75% by weight, 15 to 65% by weight, 15 to 60% by weight, 15 to 55% by weight, 15 to 50% by weight, 15 to 75% by weight 45% by weight, 15-40% by weight, 15-35% by weight, 15-30% by weight, 20-100% by weight, 20-95% by weight, 20-90 % by weight, 20-85% by weight, 20-80% by weight, 20-75% by weight, 20-70% by weight, 20-65% by weight, 20-60% by weight %, 20-55% by weight, 20-50% by weight, 20-45% by weight, 20-40% by weight, 20-35% by weight, 20-30% by weight, 2 5 to 100% by weight, 25 to 95% by weight, 25 to 90% by weight, 25 to 85% by weight, 25 to 80% by weight, 25 to 75% by weight, 25 70% to 70% by weight, 25 to 65% by weight, 25 to 60% by weight, 25 to 55% by weight, 25 to 50% by weight, 25 to 45% by weight, 25 to 4 0% by weight, 25-35% by weight, 25-30% by weight, 30-100% by weight, 30-95% by weight, 30-90% by weight, 30-85% by weight Amount%, 30-80% by weight, 30-75% by weight, 30-70% by weight, 30-65% by weight, 30-60% by weight, 30-55% by weight,The content may be, but is not limited to, 30 to 50% by weight, 30 to 45% by weight, 30 to 40% by weight, or 30 to 35% by weight.

[0051] The feed composition may be excellent in digestibility of the nutrients by salmonid fish, such as true digestibility and apparent digestibility, when fed to salmonid fish.

[0052] The feed composition may contain an indicator commonly used to measure apparent digestibility (e.g., chromium oxide (Cr2O3), yttrium oxide (Y2O3), ytterbium oxide (Yb2O3), lanthanum oxide (La2O3), dysprosium (III) oxide (Dy2O3), etc.).

[0053] The apparent digestibility may refer to the apparent digestibility of protein, the apparent digestibility of lipids, the apparent digestibility of energy, the apparent digestibility of micronutrients (e.g., the apparent digestibility of phosphorus, manganese, zinc, copper, iron, selenium, etc.), the apparent digestibility of fatty acids, etc.

[0054] The feed composition may have an apparent protein digestibility of, but is not limited to, 80-100%, 80-98%, 80-96%, 80-95%, 80-92%, 80-90%, 80-88%, 82-100%, 82-98%, 82-96%, 82-95%, 82-92%, 82-90%, 82-88%, 84-100%, 84-98%, 84-96%, 84-95%, 84-92%, 84-90%, or 84-88%.

[0055] The feed composition may have an apparent lipid digestibility of, but is not limited to, 85-100%, 85-98%, 85-96%, 85-95%, 85-93%, 87-100%, 87-98%, 87-96%, 87-95%, 87-93%, 90-100%, 90-98%, 90-96%, 90-95%, 90-93%, 91-100%, 91-98%, 91-96%, 91-95%, or 91-93%.

[0056] The feed composition may have an apparent ash digestibility of, but is not limited to, 20-40%, 20-38%, 20-35%, 20-32%, 20-30%, 22-40%, 22-38%, 22-35%, 22-32%, 22-30%, 25-40%, 25-38%, 25-35%, 25-32%, 25-30%, 26-40%, 26-38%, 26-35%, 26-32%, 26-30%, 27-40%, 27-38%, 27-35%, 27-32%, 27-30%, 28-40%, 28-38%, 28-35%, 28-32%, or 28-30%.

[0057] The feed composition may have an energy digestibility of, but is not limited to, 80-100%, 80-98%, 80-96%, 80-95%, 80-92%, 80-90%, 80-88%, 82-100%, 82-98%, 82-96%, 82-95%, 82-92%, 82-90%, 82-88%, 84-100%, 84-98%, 84-96%, 84-95%, 84-92%, 84-90%, or 84-88%.

[0058] The feed composition may have a high apparent digestibility of ash (total of minerals) or each mineral (e.g., calcium, phosphorus, magnesium, sodium, potassium, chlorine, sulfur, iron, iodine, zinc, copper, selenium, manganese, chromium, cobalt, molybdenum, fluorine, etc.), which are micronutrients.

[0059] The feed composition may have an apparent phosphorus digestibility of 30 to 70%, 30 to 67%, 30 to 65%, 30 to 62%, 30 to 60%, 30 to 57%, 30 to 55%, 30 to 52%, 30 to 50%, 32 to 70%, 32 to 67%, 32 to 65%, 32 to 62%, 32 to 60%, 32 to 57%, 32 to 55%, 32 to 52%. %, 32-50%, 35-70%, 35-67%, 35-65%, 35-62%, 35-60%, 35-57%, 35-55%, 35-52%, 35-65% 50%, 37-70%, 37-67%, 37-65%, 37-62%, 37-60%, 37-57%, 37-55%, 37-52%, 37-50%, 40 70%, 40-67%, 40-65%, 40-62%, 40-60%, 40-57%, 40-55%, 40-52%, 40-50%, 42-70%, 42-67%, 42-65%, 42-62%, 42-60%, 42-57%, 42-55%, 42-52%, 42-50%, 45-70%, 45-67 %, 45-65%, 45-62%, 45-60%, 45-57%, 45-55%, 45-52%, 45-50%, 47-70%, 47-67%, 47-65%, 47-62%, 47-60%, 47-57%, 47-55%, 47-52%, or 47-50%.

[0060] The feed composition has an apparent digestibility of iron of 1 mg / kg or more, 2 mg / kg or more, 3 mg / kg or more, 4 mg / kg or more, 5 mg / kg or more, 6 mg / kg or more, 7 mg / kg or more, 8 mg / kg or more, 9 mg / kg or more, 10 mg / kg or more, 1 to 20 mg / kg, 1 to 18 mg / kg, 1 to 15 mg / kg, 1 to 12 mg / kg, 1 to 11 mg / kg, 2 to 20 mg / kg, 2 to 18 mg / kg, 2 to 15 mg / kg, 2 to 12 mg / kg The dose may be, but is not limited to, kg, 2 to 11 mg / kg, 5 to 20 mg / kg, 5 to 18 mg / kg, 5 to 15 mg / kg, 5 to 12 mg / kg, 5 to 11 mg / kg, 8 to 20 mg / kg, 8 to 18 mg / kg, 8 to 15 mg / kg, 8 to 12 mg / kg, 8 to 11 mg / kg, 10 to 20 mg / kg, 10 to 18 mg / kg, 10 to 15 mg / kg, 10 to 12 mg / kg, or 10 to 11 mg / kg.

[0061] The feed composition may have an apparent copper digestibility of 1 mg / kg or more, 5 mg / kg or more, 10 mg / kg or more, 11 mg / kg or more, 12 mg / kg or more, 13 mg / kg or more, 14 mg / kg or more, 15 mg / kg or more, 16 mg / kg or more, 17 mg / kg or more, 1-30 mg / kg, 1-28 mg / kg, 1-25 mg / kg, 1-22 mg / kg, 1-20 mg / kg, 1-18 mg / kg, 2-30 mg / kg, 2-28 mg / kg, 2-25 mg / kg, 2-22 mg / kg, 2-20 mg / kg, 2-18 mg / kg, 5-30 mg / kg, 5-28 mg / kg, 5-25 mg / kg, 5-22 mg / kg, 5-20 mg / kg, 5-18 mg / kg, 8-30mg / kg, 8-28mg / kg, 8-25mg / kg, 8-22mg / kg, 8-20mg / kg, 8-18mg / kg, 10-30mg / kg, 10-28mg / kg, 10-25mg / kg, 10-22mg / kg, 10-20mg / kg, 10-18mg / kg, 14-30mg / kg, 14-28mg / kg, 14-25mg / kg, 14-22mg / kg, 14-20mg / kg, 14-18mg / kg, 15-30mg / kg, 15-28mg / kg, 15-25mg / kg, 15-22mg / kg, 15-20mg / kg, or 15-18mg / kg.

[0062] The feed composition has an apparent digestibility of manganese of 1 mg / kg or more, 2 mg / kg or more, 3 mg / kg or more, 4 mg / kg or more, 5 mg / kg or more, 6 mg / kg or more, 7 mg / kg or more, 8 mg / kg or more, 9 mg / kg or more, 10 mg / kg or more, 1 to 20 mg / kg, 1 to 18 mg / kg, 1 to 15 mg / kg, 1 to 12 mg / kg, 1 to 11 mg / kg, 2 to 20 mg / kg, 2 to 18 mg / kg, 2 to 15 mg / kg, 2 to 12 mg / kg The dose may be, but is not limited to, 2 to 11 mg / kg, 5 to 20 mg / kg, 5 to 18 mg / kg, 5 to 15 mg / kg, 5 to 12 mg / kg, 5 to 11 mg / kg, 8 to 20 mg / kg, 8 to 18 mg / kg, 8 to 15 mg / kg, 8 to 12 mg / kg, 8 to 11 mg / kg, 10 to 20 mg / kg, 10 to 18 mg / kg, 10 to 15 mg / kg, 10 to 12 mg / kg, or 10 to 11 mg / kg.

[0063] The feed composition has an apparent digestibility of zinc of 1 mg / kg or more, 5 mg / kg or more, 10 mg / kg or more, 15 mg / kg or more, 20 mg / kg or more, 25 mg / kg or more, 30 mg / kg or more, 1 to 50 mg / kg, 1 to 45 mg / kg, 1 to 40 mg / kg, 1 to 35 mg / kg, 5 to 50 mg / kg, 5 to 45 mg / kg, 5 to 40 mg / kg, 5 to 35 mg / kg, 10 to 50 mg / kg, 10 to 45 mg / kg, 10 to 40 mg / kg, 10 to 35 mg / kg, 15-50 mg / kg, 15-45 mg / kg, 15-40 mg / kg, 15-35 mg / kg, 20-50 mg / kg, 20-45 mg / kg, 20-40 mg / kg, 20-35 mg / kg, 25-50 mg / kg, 25-45 mg / kg, 25-40 mg / kg, 25-35 mg / kg, 27-50 mg / kg, 27-45 mg / kg, 27-40 mg / kg, or 27-35 mg / kg.

[0064] The microalgae-derived biomass or a feed composition containing the microalgae-derived biomass has excellent digestibility of the nutrients and can be useful as feed for salmonid fish. The microalgae-derived biomass or a feed composition containing the microalgae-derived biomass can be used to enhance (increase) the digestibility of salmonid fish.

[0065] Another embodiment provides a method for producing a feed composition for salmonid fish containing microalgae-derived biomass, the method including the steps of blending feed and a binder to produce a feed formulation, adding water to the feed formulation, mixing the mixture, and then forming the mixture into a predetermined shape.

[0066] The binder may be added to enhance the binding power and water absorption capacity of the feed, and may include one or more carbohydrate components selected from the group consisting of grain flour selected from wheat flour, corn flour, rice flour, barley flour, potato flour, and sweet potato flour; tapioca starch, potato starch, sweet potato starch, rice starch, oat starch, soybean starch, wheat starch, and modified starches thereof. The modified starch refers to natural starch that has been chemically, physically, or enzymatically treated, and may be, for example, dextrin, oxidized starch, oxygen-treated starch, alpha (α) starch, starch derivatives, etc., but is not limited thereto.

[0067] The feed compound may be formed using a conventional known device, preferably any one selected from the group consisting of an extruder, an impeller mixer, and a kneader. Through this forming process, the feed compound may be formed into the form of granules, pills, or pellets.

[0068] The method for preparing the feed composition may further include a drying step, if necessary, after the step of forming the feed composition is completed. The drying method may be any known drying method, such as natural drying, hot air drying, or high-temperature drying. During the drying process, the fish feed may be dried in a semi-dry state, containing some moisture, or in a completely dry state.

[0069] Still other embodiments provide a method for cultivating salmonid fish or a method for increasing the digestibility of salmonid fish, comprising the step of feeding the microalgae-derived biomass or a feed composition containing the microalgae-derived biomass to salmonid fish; or a use of the microalgae-derived biomass or a feed composition containing the microalgae-derived biomass for increasing the digestibility of salmonid fish.

[0070] The feed composition and the salmonid fish are as described above.

[0071] By feeding salmonid fish with a feed composition containing the microalgae-derived biomass, the digestibility of the salmonid fish is increased, allowing salmonid fish to be farmed efficiently.

[0072] The digestibility of salmonid fish may be the nutrient digestibility of salmonid fish, and may be true digestibility, apparent digestibility, or the like.

[0073] The apparent digestibility of the salmonid fish may mean the apparent digestibility of protein, the apparent digestibility of lipids, the apparent digestibility of energy, the apparent digestibility of micronutrients (e.g., the apparent digestibility of phosphorus, manganese, zinc, copper, iron, selenium, etc.), the apparent digestibility of fatty acids, or the apparent digestibility of ash (total of minerals) which is a micronutrient, or each mineral (e.g., calcium, phosphorus, magnesium, sodium, potassium, chlorine, sulfur, iron, iodine, zinc, copper, selenium, manganese, chromium, cobalt, molybdenum, fluorine, etc.), or the like.

[0074] The digestibility of the feed composition containing the microalgae-derived biomass may be increased by 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, 95% or more, 100% or more, 105% or more, or 110% or more, compared to a control group (e.g., a feed composition not containing microalgae-derived biomass).

[0075] In one example, the phosphorus digestibility of the feed composition containing the microalgae-derived biomass may be increased by 5% or more, 10% or more, 15% or more, or 20% or more compared to a control group. In one example, the iron digestibility of the feed composition containing the microalgae-derived biomass may be increased by 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 100% or more compared to a control group. In one example, the copper digestibility of the feed composition containing the microalgae-derived biomass may be increased by 5% or more or 10% or more compared to a control group. In one example, the manganese digestibility of the feed composition containing the microalgae-derived biomass may be increased by 10% or more, 20% or more, 30% or more, or 40% or more compared to a control group. In one example, the zinc digestibility of the feed composition containing the microalgae-derived biomass may be increased by 5% or more, 10% or more, or 15% or more compared to a control group. [Effects of the Invention]

[0076] The feed composition containing the microalgae-derived biomass of the present application does not cause any factors that reduce the quality of the feed, and can be usefully used in fish feed compositions using microalgae that are high in protein, fat, and minerals. [Brief explanation of the drawings]

[0077] [Figure 1] Figure 1 is a graph showing the apparent digestibility of trace elements (minerals: phosphorus, iron, copper, manganese, and zinc) in the test diet (algal protein diet) compared with the control diet (SPC diet) and the standard diet (reference diet). [Figure 2] Figure 2 is a graph showing the apparent digestibility of dietary fatty acids (total saturated fatty acids, total monounsaturated fatty acids, total omega-6 fatty acids, total omega-3 fatty acids, total polyunsaturated fatty acids, EPA + DHA) in the test diet (algal protein diet) compared with the standard diet (reference diet). [Example]

[0078] The present application will be described in more detail below with reference to the following examples, which are merely for illustrative purposes and are not intended to limit the scope of the present application, and are obvious to those skilled in the art.

[0079] Therefore, the present invention will be described in more detail through examples.

[0080] Example 1: Preparation of test diet Efficient feed production requires a quality evaluation of feed ingredients relative to their price. Measuring the nutrient digestibility of a feed ingredient is one of the most basic methods for evaluating a feed ingredient. Among methods for measuring nutrient digestibility in fish, an indirect method is used, where an indicator substance such as yttrium oxide is mixed with the feed to measure digestibility. Furthermore, evaluation of the nutrient digestibility of a feed ingredient is generally performed by feeding fish with a test feed made by mixing a basal feed (standard feed) with the feed ingredient to be evaluated in a 7:3 ratio. This is to minimize the influence of other feed ingredients on the feed ingredient to be evaluated.

[0081] 1-1. Analysis of major nutrients and components by experimental component In this example, the feed ingredients tested were biomass derived from microalgae, fish meal / fish oil as the standard feed ingredients, and soy protein concentrate (SPC, a product of CJ CheilJedang), a plant-based alternative protein, as the comparative feed ingredient. The microalgae-derived biomass was produced using Schizochytrium sp. (KCTC14345BP). Specifically, Schizochytrium microalgae were mass-cultured, dried, and packaged. The culture solution of Schizochytrium microalgae, which had been cultured at a high concentration through the cultivation process, was transferred to a tableting process. The moisture content of the culture solution was reduced through a dehydration process, and the solution was dried and powdered using drum drying or spray drying. The final Schizochytrium microalgae powder was packaged and stored, and used in the following examples.

[0082] To utilize them in salmon feed, each raw material was analyzed for its major nutrients, such as crude protein, crude fat, ash, and moisture, as well as the content of trace nutrients (minerals), such as fatty acids, phosphorus, manganese, and zinc. The nutritional composition of each raw material is shown in Table 2 below.

[0083] [Table 2] JPEG2026506803000005.jpg14149

[0084] Table 2 above analyzes the crude protein, crude fiber, ash, moisture, and fat composition (weight %) of each raw material (microalgae-derived biomass, concentrated soy protein, and fish meal), with the remaining components including nitrogen-free extracts such as starch, sugars, cellulose, and lignin. Phosphorus is contained in the ash and was analyzed separately. In Table 2 above, the amino acid content refers to the weight of each amino acid measured based on 100g of total amino acids. In Table 2 above, the fatty acid content refers to the weight of each fatty acid measured based on 100g of total lipids. The fatty acid content of the concentrated soy protein in Table 2 above is as follows: the total saturated fatty acid content is palmitic acid (C16:0) 0.31 and stearic acid (C18:0) 0.08; the total monounsaturated fatty acid content is oleic acid (C18:1 n-9) 0.4; the total omega-6 fatty acid content is linoleic acid (C18:2 n-6) 0.91; and the total omega-3 fatty acid content is α-linolenic acid (C18:3 n-3) 0.1.

[0085] 1-2. Feed production and composition The standard diet was made up of a feed mix containing fish meal, fish oil, wheat, a vitamin and mineral mix.

[0086] [Table 3]

[0087] The standard feed was prepared according to the composition shown in Table 3, while the test feed and comparative feed were prepared by replacing 30% by weight of the standard feed with microalgae-derived biomass or concentrated soy protein, respectively. The nutritional composition of the test feed, comparative feed, and standard feed is shown in Table 4 below.

[0088] [Table 4] JPEG2026506803000008.jpg20149

[0089] Table 4 above shows the crude protein, ash, moisture, and fat composition (weight %) of each feed (test feed, comparative feed, and standard feed). The remaining components include starch, sugars, cellulose, lignin, and other nitrogen-free extracts, as well as crude fiber. Minerals such as phosphorus, selenium, iron, copper, manganese, and zinc were measured as their content (mg / kg) per 1 kg of total feed. In Table 4 above, the amino acid content refers to the weight of each amino acid measured based on 100 g of total amino acids. In Table 4 above, the fatty acid content refers to the weight of each fatty acid measured based on 100 g of total lipids.

[0090] To evaluate the specific digestibility of nutrients in Atlantic salmon molt (obtained from Nofima, Norway), the test and control diets were prepared using the standard partial substitution method, with 70% by weight of the standard diet being replaced by 30% by weight of each ingredient (microalgae-derived biomass and concentrated soy protein). The digestibility indicator yttrium oxide (YO, obtained from Sigma-Aldrich, product number 205168) was added for subsequent analysis.

[0091] 1-3. Analysis of experimental feed and fish body components Raw materials, feed, and feces were analyzed for crude protein (Kjeldahl method Nx 6.25; ISO 5983-1997), moisture (ISO 6496-1999), ash (ISO 5984-2002), and lipids to confirm their approximate composition. Fatty acid profiles were determined using a micro-GC gas chromatograph according to AOCS official method Ce 1b-89. Total and soluble phosphorus were measured spectrophotometrically (ISO 6491-1998).

[0092] Example 2: Fish and tank setup The Atlantic salmon fry (Nofima, Norway) used in the experiment had an average weight of 105g and were housed in tanks of 100 fish, randomly distributed in three replicates per experimental group. The water temperature was maintained at 12°C. The rearing experiment lasted for four weeks. Oxygen saturation was measured three times in all test groups during the experiment to control water quality, and was found to be similar across the test groups.

[0093] Before the experimental fish populations were introduced, pre-weighed amounts of each experimental diet were provided to the experimental tanks. Each diet (test, comparison, and standard) was provided to the tanks in pellet form, and the pellets were collected through a sieve and washed with drainage water at specific times during the experiment between feeding and collection. The feed pellets were then reweighed to determine the dry matter solubility (water stability) of each diet. This value was used to recalculate the total amount of unconsumed feed per tank and monitor the daily feed intake of each experimental population.

[0094] Briefly, uneaten feed was collected and weighed daily to estimate the total daily feed intake of the experimental fish groups.

[0095] Example 3. Sampling and Digestibility Calculation After the experiment, all fish were removed from each tank and feces were collected in a box for each tank. The collected feces were freeze-dried, pulverized, and stored at -20°C until analysis. The bulk weight was added to the weight of the fish in each tank to calculate the average weight.

[0096] The yttrium oxide (Y2O2) (digestibility indicator) content in the experimental feed and feces was analyzed using an ICP-OES (Agilent 5110 VDV, inductively coupled plasma optical emission spectrometer) (Reference: NS:EN 15641:2017).

[0097] Example 4: Comparison of digestibility by feed 4-1. Nutrient digestibility The apparent digestibility of nutrients (protein, lipid, ash, energy) of the test diets, comparative diets, and standard diets in Atlantic salmon fry is shown in Table 5 below.

[0098] [Table 5]

[0099] As can be seen from Table 5 above, the test feed showed similar levels of protein digestibility and lipid digestibility compared to the comparative feed and standard feed. In particular, it was confirmed that the test feed had higher ash digestibility and energy digestibility compared to the comparative feed. These results indicate that the test feed containing the microalgae-derived biomass of the present application can be useful as fish feed.

[0100] 4-2. Micronutrient digestibility The apparent digestibility of micronutrients (phosphorus, iron, copper, manganese, zinc) in the test, comparative, and standard diets for Atlantic salmon fry is shown in Table 5 below and Figure 1.

[0101] Like land animals, fish require various minerals as nutritional sources, including phosphorus (P), manganese (Mn), zinc (Zn), copper (Cu), iron (Fe), selenium (Se), etc. Looking at the functions and roles of each mineral, phosphorus (P) is used in skeletal tissues and phospholipids, copper (Cu) and zinc (Zn) act as metalloenzymes, iron (Fe) in hemoglobin, manganese (Mn) in skeletal tissues and in enzyme reactions, and selenium (Se) has antioxidant properties.

[0102] As can be seen from Table 6 and Figure 1 below, the test feed had higher digestibility of ash and phosphorus than the comparative feed, and the digestibility of phosphorus in the test feed was particularly higher than that of the standard feed.

[0103] This is because all of the phosphorus (P) in microalgae-derived biomass feedstocks is water-soluble, whereas the phosphorus (P) in fishmeal is partially bound to indigestible bone-derived hydroxyapatite.

[0104] Furthermore, while microalgae-derived biomass materials contain relatively high levels of phospholipids, the phosphorus (P) in plant-derived proteins (e.g., bran, seeds, etc.) is mostly present in the form of inositol phosphates (e.g., phytate), which have low bioavailability and are known to inhibit the intestinal absorption of other dietary minerals (e.g., Ca, Fe, Zn). In addition to phosphorus (P), the test feed also had significantly better digestibility of iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn), which are essential trace elements digestible by salmon, compared to the comparison feed and standard feed.

[0105] [Table 6]

[0106] 4-3. Fatty acid digestibility The apparent digestibility of fatty acids in the test and standard diets for Atlantic salmon fry is shown in Table 7 below and Figure 2.

[0107] The fatty acids in the feed can also directly contribute to fish quality through the fatty acid composition of the fish. As can be seen from Table 6 below, the test feed contained equal or higher levels of unsaturated fatty acids than the standard feed. This means that the test feed, like the comparative feed, contains high amounts of unsaturated fatty acids, such as the essential fatty acids eicosapentaenoic acid (EPA (C20:5 n-3)) and docosahexaenoic acid (DHA (C22:6 n-3)), and is therefore considered to be a good source of essential fatty acids for fish. Furthermore, saturated fatty acids have a higher melting point than unsaturated fatty acids and can exist as a solid in water at room or low temperature. Therefore, the test feed has a lower saturated fatty acid content than the standard feed, making it suitable for use as fish feed.

[0108] [Table 7]

[0109] Example 5: Feed ingredient digestibility (Partial ADC of test ingredient nutrients) In Example 5, the nutrient digestibility of each of the ingredients contained in the feeds of Example 4 (test feed, comparative feed, standard feed) was measured.

[0110] 5-1. Nutrient digestibility The nutrient digestibility of the feed ingredients was determined and is shown in Table 8 below.

[0111] [Table 8]

[0112] As can be seen from Table 8 above, the protein and fat digestibility of the test feed ingredients was similar to that of the comparative feed and the standard feed, but the digestibility of iron, copper, manganese, zinc, and phosphorus was significantly superior to that of the comparative feed and the standard feed.

[0113] 5-2. Fatty acid digestibility The fatty acid digestibility of the feed ingredients was measured and is shown in Table 9 below.

[0114] [Table 9]

[0115] As can be seen from Table 9 above, the test feed had similar or even higher apparent digestibility of unsaturated fatty acids compared to the standard feed. Furthermore, the test feed also had a similar apparent digestibility to the control feed for omega-3 highly unsaturated fatty acids (HUFA), such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are essential fatty acids required by marine fish and functional substances found in large amounts in fish oil. Furthermore, the test feed had a lower apparent digestibility of saturated fatty acids compared to the standard feed, demonstrating its beneficial effects when used as fish feed.

[0116] From the above description, it should be understood by those skilled in the art that the present invention can be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. In this regard, it should be understood that the above-described embodiments are illustrative in all respects and are not limiting. The scope of the present invention should be interpreted as including all modifications and variations derived from the meaning and scope of the claims below, rather than the above detailed description, and equivalent concepts thereof.

[0117] [Accession number] Depository institution: Korea Microorganism Collection Center Accession number: KCTC14345BP Date of acceptance: 20201026

Claims

1. A feed composition for salmonid fish containing biomass derived from microalgae.

2. The feed composition for salmonid fish according to claim 1 , wherein the microalgae are of the genus Schizochytrium.

3. 2. The feed composition for salmonid fish according to claim 1, wherein the microalgae-derived biomass comprises one or more species selected from the group consisting of microalgae, a culture of the microalgae, a dried product of the culture, and a crushed product of the dried product.

4. 2. The feed composition for salmonid fish according to claim 1, wherein the salmonid fish is one or more species selected from the group consisting of fish of the genera Whitefish, Prosopium, Stenodus, Grayling, Salvelinus, Salmon, Oncorhynchus, Sakhalin, Salmonella, Salvetimus, and Salvetimus.

5. The feed composition for salmonid fish according to claim 1, wherein the salmonid fish is Atlantic salmon (Salmo salar).

6. 2. The feed composition for salmonid fish according to claim 1, wherein the microalgae-derived biomass contains 50 to 90% by weight of protein.

7. 7. The feed composition for salmonid fish according to claim 6, which contains 1 to 100% by weight of the biomass derived from the microalgae.

8. 2. The feed composition for salmonid fish according to claim 1, wherein the nutrient digestibility of phosphorus is 40 to 60%.

9. 2. The feed composition for salmonid fish according to claim 1, wherein the nutrient digestibility of the ash is 26 to 40%.

10. 2. The feed composition for salmonid fish according to claim 1, which is in the form of extruded pellets or moist pellets.

11. A method for producing the feed composition for salmonid fish according to any one of claims 1 to 10.

12. A method for cultivating salmonid fish, comprising the step of feeding salmonid fish biomass derived from microalgae or the feed composition for salmonid fish according to any one of claims 1 to 10.

13. A method for increasing the digestibility of salmonid fish, comprising the step of feeding the salmonid fish a biomass derived from microalgae or the feed composition for salmonid fish according to any one of claims 1 to 10.

14. 11. Use of biomass derived from microalgae or the feed composition for salmonid fish according to any one of claims 1 to 10 for increasing the digestibility of salmonid fish.

15. A composition for enhancing digestibility of salmonid fish, comprising biomass derived from microalgae or the feed composition for salmonid fish according to any one of claims 1 to 10.

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