Gel structure for promoting the substitution of live feed for short-term aquatic organisms

Abstract

Disclosed is a nutritional supplement suitable for ingestion by shrimp or fish larvae. This nutritional supplement includes a particulate gel structure containing agar, an attractant, and water, and an aqueous medium containing at least one salt. The particulate gel structure can be in the form of gelled particles, for example, granules, and these gelled particles can be added to the aqueous medium. The present invention further relates to a method for producing this nutritional supplement and a method for feeding this nutritional supplement to shrimp larvae or fish larvae together with at least one hydrated or dry feed, for example, a hydrated or dry complete feed.

Description

Technical Field

[0001] The present invention relates to a nutritional supplement suitable for ingestion by larvae of shrimp or fish. This nutritional supplement contains a particulate gel structure (such as granules, which can be in the form of gelled particles). This gel structure is dispersed in an aqueous medium containing at least one salt, for example, sodium chloride. The present invention also relates to a method for producing this nutritional supplement. The present invention further relates to a method for feeding this nutritional supplement to larvae of shrimp or fish together with at least one hydrated or dry feed, for example, a hydrated or dry complete feed.

Background Art

[0002] [Abbreviations] ALF Artificial life feed ALF(P), ALFP Feeding of sterilized artificial life feed ALFF Artificial life feed given in a fixed feeding amount ALFV Artificial life feed given in a varying feeding amount ART Artemia DD Dry feed M1, M2, M3 Mysis stage 1, 2, 3 N5 Nauplius stage 5 Z1, Z2, Z3 Zoea stage 1, 2, 3 PLn Postlarval stage n

[0003] Although the physical and nutritional performance of dry feeds for the culture of larvae of marine fish and shrimp has been improved, live feed is still required during these critical periods of early development. Live feed mainly consists of rotifers and Artemia, and sometimes also includes wild-like zooplankton harvested from nature or generated in hatcheries.

[0004] On the one hand, there is always a biological risk that diseases can be transmitted through live feed production. On the other hand, since the nutritional conditions of these moist feeds are insufficient and variable, numerous disinfection and nutrient enrichment methods have been developed. All of these operations and treatments ultimately incur various additional operating costs, but they are essential to improve the quality of live feed to a state of moist feed that meets the conditions.

[0005] Many attempts have been made to fully incorporate the nutritional components of live feed into so-called dry or moist alternative feeds, but none are completely satisfactory. To meet the requirements of small aquatic organisms, the latest dry feeds (often manufactured in pharmaceutical facilities) (such as micro bound particles, micro coated particles, microcapsules with protein walls, etc.) have been developed to contain as many nutrients as possible and have chemical characteristics, but it has been difficult to achieve a good balance of water stability, particle digestibility, and buoyancy.

[0006] Due to the high water content, moist feeds generally result in floating formulations, but in a single matrix, high elution and preservation are issues in retaining peptides, amino acids, vitamins, and highly oxidizable essential lipophilic and hydrophilic components.

[0007] Perhaps the best compromise to solve the problem of live food substitutes is to provide both hydrated and dry feeds and combine their best characteristics. Feeding dry feed together with live food before weaning is a well-established means, and further research on dry and hydrated feeds may now make it possible to mimic the feeding methods currently used with live food. For shrimp and fish, this means that during the critical periods before molting and pre-metamorphosis (for fish) to the early PL stages (post-larval stage; for shrimp), live food can be reduced to its bare essential functions and components that are lacking in dry feed. The present invention aims to improve or reduce at least one drawback of the prior art, or at least to provide a useful alternative to the prior art.

[0008] Live food, which has been analyzed for decades, is hardly unknown about the nutritional components that make up its body composition. Functional nutrients are well known and can be incorporated into dry feeds without the need to replicate them in hydrated feed formulations. In this regard, it is considered better to use hydrated feed as a complement to chemically incompatible nutrients in dry feeds, but it can also be used to provide temporary specific boosts during critical periods. Highly sensory-stimulating attractive molecules and excellent physical floating properties are expected to attract larvae more and, if necessary, cause this new generation of hydrated feeds to be ingested.

[0009] The life cycle of the kuruma shrimp includes eggs, nauplius stages (1 - 6), zoea stages (1 - 3), mysis stages (1 - 3), post-larval stages (PLn), juvenile stages, sub-adult stages, and adult stages. The life cycle of fish depends on the fish species and generally includes eggs, larvae, juveniles, and adults, although some fish species may be different.

[0010] Artemia is used in most shrimp hatcheries, but its use is very limited during the larval rearing period and forms a small part of the total volume of the formulated (dry) feed given. The average Artemia cyst consumption is generally limited to 1 - 5 kg of cysts per million shrimp produced.

[0011] There are several reasons for the limited use of Artemia, but the most important ones are cost, biological risk issues, sustainability, chemical contamination, hatching variability, and quality problems. Despite all these problems, Artemia is still used because it plays a unique role in overcoming the critical period in the initial shrimp development from mysis to early postlarva.

[0012] Artemia factors that confer special benefits to shrimp larvae have been studied for many years but are not fully understood. There are many hypotheses, such as buoyancy and motility, digestibility of an organism that is easily self - digested, associated bacterial populations, micronutrients, enzymes, hormones, etc.

[0013] Presumably, Artemia factors are the result of a complex multi - factor combination of physical, microbial, and nutritional combinations, which are highly variable and, on the other hand, act complementarily (for example, but not limited to the following), making it difficult to mimic. · Digestibility enhancement by easy hydration of dry feed with live feed containing about 90% water · Re - colonization of the larval digestive tract by various bacterial populations released from the body and intestinal flora of live feed that quickly self - decompose after ingestion by fish or shrimp · Protection of the digestive tract by a soft matrix formed by live feed and a harder dry feed · Softness and movement of the life prey that promote peristaltic movement of the digestive tract

[0014] [Dry and Moist Feed] According to the size and growth stage of shrimp and fish, dry feed particles with sizes in the range of, for example, 50 μm to 100 μm, 100 μm to 200 μm, 200 μm to 300 μm, 300 μm to 400 μm, and 400 μm to 500 μm are provided.

[0015] Moist feeds are generally of the same size as dry feeds and / or Artemia, assuming complete replacement. Such feeds consist of a mixture of a complete list of gelling substances / binders, water, and nutritional components (i.e., fat sources, protein sources, minerals, vitamins, etc.). Another moist feed is designed for on-growing fish or shrimp in aquaculture long after live feed has been stopped. Some moist feeds are only used in aquariums as a hobby, and the animals are not used in the food chain.

[0016] International Patent Application Publication No. 02 / 078463 discloses a microbound feed product formulated for the culture of larval fish and crustaceans, which feed is in either dry or moist form and contains proteins (such as fish protein hydrolysate, casein, egg yolk, etc.) and binders (such as soy lecithin, wheat gluten, alginate, etc.).

[0017] International Patent Application Publication No. 02 / 071867 discloses a firm, non-liquid particulate food composition that is easy to adapt to the nutritional requirements of aquatic organisms. The food of this invention contains feed particles of oil-coated nutrients and nutrients added with moisture, embedded in a gel or edible polymer mixture. The gel, which is gelled alginate and gelatin, is cross-linked with a water-soluble, polyvalent, antibacterial salt (such as calcium chloride).

[0018] European Patent No. 1006807 discloses an aqueous animal feed for substituting frozen feed, which contains 0.001 to 50% gelling agent and 0.1 to 90% natural nutrients, has a water content of 20 to 99%, and is in the form of a sticky gel with a viscosity of 1 to 2×10 6 mPa·s.

Prior Art Documents

Patent Documents

[0019]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0020] The present invention aims to improve, reduce, or at least present a useful alternative to at least one drawback of the prior art. More specifically, the object of the present invention is to improve the feeding of fish and / or shrimp larvae (preferably without using live feed), and / or to improve the growth and / or survival rate of fish larvae and / or shrimp larvae.

Means for Solving the Problems

[0021] This object is achieved through the features specifically described in the following description and the subsequent claims.

[0022] The main idea of the present invention is to move away from dry or hydrated complete feeds (i.e., nutritionally complete diets), focusing on the drawbacks of dry or hydrated feeds, particularly during the periods when they cause difficulties for larval shrimp and fish, especially during molting, weaning, or diet transition. During this period, the animals undergo dramatic transformations using special diets and digestive requirements, but their digestive systems, which rely on the interaction between live prey and bacteria that partially digest the ingested food, are not yet fully developed. Without wishing to be bound by theory, the gist of the present invention is to create a nutritional supplement, i.e., a physical-nutritional particulate gel structure dispersed in an aqueous medium containing at least one salt, such as salt water, to replace specific functions of live prey and to facilitate the ingestion and digestion of the dry feed fed together therewith. This particulate gel structure is buoyant, rich in moisture, and can also be used for bacterial attachment and electrolyte exchange.

[0023] The disclosure of the present invention relates to a nutritional supplement comprising a particulate gel structure stored in an aqueous medium containing at least one salt, which nutritional supplement replaces the functions of live prey. This nutritional supplement is preferably fed together with conventional and / or commercially available formulated dry feeds during the critical transformation periods of larval shrimp and fish.

Brief Description of the Drawings

[0024]

Figure 1A

Figure 1B

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Figure 3A

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Figure 5B

Modes for Carrying Out the Invention

[0025] Surprisingly, this nutritional supplement is nutritionally incomplete, i.e., it does not contain all the nutrients necessary for the rearing of fish larvae and / or shrimp larvae. However, when fed together with a nutritionally complete formulated dry feed by itself, it has been found that the survival rate of shrimp larvae from the mysis stage to the early PL stage improves to the same level as when live feed is provided together.

[0026] According to one aspect disclosed in the present invention, a mixture comprising a gelling agent, an attractant, and water, and optionally a colorant, omega-3 fatty acids, and phospholipids can be gel-solidified to pre-form a particulate water-containing gel structure.

[0027] As used herein, the term "mass percent" or "wt%" refers to the mass percentage on a wet weight basis (also known as "as-is basis"), i.e., water or moisture is part of the composition in which the content of each specified component is calculated. This is different from the dry basis where the mass of the specified component is represented as a percentage of the completely dry solid, i.e., excluding the water or moisture content.

[0028] After gel-solidification, the particulate gel structure can be wet sieved and diluted in an aqueous medium containing at least one salt to obtain a nutritional supplement. The aqueous medium containing at least one salt can contain about 100 - 200 ppt of NaCl. The nutritional supplement can be stored in cans.

[0029] The present invention is defined by the independent patent claims. The dependent claims specify advantageous embodiments of the present invention.

[0030] In a first aspect, the disclosure of the present invention relates to a nutritional supplement suitable for ingestion by shrimp or fish larvae, the nutritional supplement comprising I) a particulate gel structure, and II) an aqueous medium containing at least one salt and wherein the particulate gel structure a) agar, b) an attractant, and c) water are included.

[0031] This nutritional supplement can further include components selected from the group consisting of a coloring agent, omega-3 fatty acids, and phospholipids, or any combination thereof. In another embodiment, this nutritional supplement further includes a coloring agent, omega-3 fatty acids, and phospholipids.

[0032] The aqueous medium can contain at least 80 ppt (at least 100 ppt, at least 125 ppt, at least 150 ppt, at least 175 ppt, at least 200 ppt, etc.) of salts. The aqueous medium can contain salts up to 500 ppt, preferably up to 400 ppt, more preferably up to 300 ppt, and even more preferably up to 250 ppt. The salts can be any salts. A person skilled in the art could select appropriate salts. Examples of salts include, but are not limited to, sodium chloride, magnesium chloride, calcium chloride, potassium chloride, sodium carbonate, magnesium carbonate, calcium carbonate, potassium carbonate, sodium sulfate, magnesium sulfate, calcium sulfate, and potassium sulfate, or any combination thereof. In a preferred embodiment, the aqueous medium contains sodium chloride, preferably at least 80 ppt (at least 100 ppt, at least 125 ppt, at least 150 ppt, at least 175 ppt, at least 200 ppt, etc.) of sodium chloride, and also contains sodium chloride up to 400 ppt (up to 350 ppt, up to 325 ppt, up to 300 ppt, up to 250 ppt, etc.). Sodium chloride has the advantage of acting as a preservative to prevent the spoilage of the nutritional supplements taught in this application. However, other salts can also be used for this purpose. The aqueous medium may further contain other salts as taught in this application.

[0033] The particulate gel structure can be in the form of individual gelled particles such as granules, desirably having a particle size between 1 μm and 2 mm. These granules can have a size between 5 μm and 800 μm (between 20 μm and 600 μm, between 50 μm and 300 μm, between 50 μm and 200 μm, etc.). The particulate gel structure may be solidified into such individual granules having such a particle size. Since the gel structure is prepared by means of coagulation, and thus, in the solid (although gelled) state, to emphasize that the particles are not dried after coagulation or gelation, the particulate gel structure may be referred to as a particulate wet congealed gel structure.

[0034] The particulate gel structure (e.g., in the form of gelled particles such as granules) is buoyant, has slow sedimentation, or desirably has neutral buoyancy, i.e., it can stay afloat in a water column without floating up and down. This may have a density, for example, between 0.995 and 1.200 g / mL. Such a density allows it to have appropriate buoyancy, for example, neutral buoyancy, in an aquarium commonly used for rearing fish and / or shrimp larvae.

[0035] The gelled particles (e.g., granules) can be obtained by techniques such as compression, spraying, coagulation, aggregation, etc. Using agar can hold various components together. The gelled particles (e.g., granules) can themselves also contain smaller particles. The gelled particles (e.g., granules) can have any shape, for example, circular, oval, square, or an elongated shape like grains.

[0036] The particulate gel structure or nutritional supplement taught in the present application can contain agar between 0.01 and 10% by mass (between 0.05 and 7.5% by mass, between 0.1 and 6% by mass, between 0.5 and 5% by mass, between 1 and 4% by mass, between 1.5 and 3% by mass, between 1.5 and 2.5% by mass, etc.) on a wet weight basis.

[0037] The attractant can be an amino acid, a mixture of amino acids, a dipeptide, a polypeptide, a mixture of dipeptides, a mixture of polypeptides, a mixture of dipeptides and polypeptides, a hydrolyzed protein source, or any mixture of amino acids, dipeptides, polypeptides, and hydrolyzed protein sources. The protein source can be of plant or animal origin, and can also be of aquatic or marine origin (such as zooplankton, fish, etc.). The attractant can be supplied as a dry powder, a hydrated paste, or a solution. The amount of the attractant present in the particulate gel structure or nutritional supplement taught in the present application can be between 0.0001 and 20% by mass (between 0.0005 and 18% by mass, between 0.001 and 16% by mass, between 0.005 and 14% by mass, between 0.01 and 12% by mass, between 0.05 and 10% by mass, between 0.1 and 8% by mass, between 0.5 and 6% by mass, etc.).

[0038] The omega-3 fatty acid can preferably be selected from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and is preferably DHA. Fish meal, fish oil, seaweed, and phytoplankton are the primary sources of EPA and DHA, and DHA and EPA are accumulated in larval fish and / or shrimp that eat these algae and phytoplankton. However, currently, omega-3 fatty acids are also available from plant sources (such as Brassicaceae plants) (optionally genetically modified). In one embodiment, the omega-3 fatty acid can be of animal origin. In another embodiment, the omega-3 fatty acid source can be of plant origin. The omega-3 fatty acid source can contain DHA of animal origin. Alternatively, or in addition, the omega-3 fatty acid source can contain DHA of plant origin. The amount of the omega-3 fatty acid (e.g., DHA) present in the particulate gel structure or nutritional supplement taught in the present application can be between 0.001 and 20% by mass (between 0.005 and 18% by mass, between 0.01 and 16% by mass, between 0.05 and 14% by mass, between 0.1 and 10% by mass, between 0.5 and 6% by mass, etc.).

[0039] The phospholipids can include lecithin. Lecithin is a mixture of glycerophospholipids (including phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and phosphatidic acid). These are themselves good sources of various phospholipids. Lecithin can be from any available raw material, including but not limited to egg yolk, marine sources, soybeans, milk, rapeseed, cottonseed, and sunflower oil. In one embodiment, the lecithin can be soy lecithin. The abundance of phospholipids (e.g., lecithin) in the particulate gel structure or nutritional supplement taught in the present application can be between 0.01 and 20% by mass (between 0.05 and 15% by mass, between 0.1 and 10% by mass, between 0.5 and 6% by mass, etc.).

[0040] The coloring agent can be any coloring agent as long as it makes the particulate gel structure visible in an aquarium commonly used for breeding shrimp and / or fish larvae. The coloring agent can be a pigment, a dye, or an ionized solution. In certain embodiments, the coloring agent can be selected from the group consisting of carotenoids (such as carotenes, xanthophylls, etc.), carbon, clay, minerals, anthocyanins, colored algae (such as red algae, green algae, etc.). In certain embodiments, the coloring agent can be a carotenoid, desirably a xanthophyll, more desirably astaxanthin.

[0041] The abundance of the coloring agent in the particulate gel structure or nutritional supplement taught in the present application can be between 0.0001 and 20% by mass (between 0.0005 and 18% by mass, between 0.001 and 16% by mass, between 0.005 and 14% by mass, between 0.01 and 12% by mass, between 0.015 and 10% by mass, between 0.02 and 8% by mass, between 0.1 and 6% by mass, between 0.5 and 5% by mass, etc.), depending on the type of coloring agent used. A person skilled in the art can select the exact amount of the coloring agent necessary to obtain the desired effect.

[0042] The particulate gel structure can contain, for example, 0.01 to 10% by mass of agar, 0.01 to 10% by mass of an attractant, 0.1 to 3% by mass of DHA, 0.01 to 10% by mass of phospholipids, 0.01 to 20% by mass of a colorant, and 40 to 95% by mass of water, based on wet weight.

[0043] The mass ratio of the particulate gel structure to the aqueous medium can be between 0.2:1 and 1:0.2, preferably between 0.5:1 and 1:0.5, more preferably between 0.75:1 and 1:0.75.

[0044] In a second aspect, the disclosure of the present application relates more particularly to a method of preparing a nutritional supplement suitable for co-feeding with shrimp larvae or fish larvae as taught in the present application, the method comprising: i) coagulating a gelling mixture comprising agar, water, and an attractant, and optionally an omega-3 fatty acid, phospholipids, and / or a colorant, to produce a particulate gel structure (such as granules); ii) optionally wet-sieving the particulate gel structure (such as granules) to obtain a particulate gel structure of a suitable size; iii) adding the particulate gel structure to an aqueous medium containing at least one salt to obtain a nutritional supplement suitable for ingestion by shrimp or fish larvae. and

[0045] Preferably, the gelling mixture is heated to a temperature at which the agar in the gelling mixture melts, and then the gelling mixture is solidified, for example, by forming appropriate particles and solidifying them, thereby coagulating the gelling mixture. A person skilled in the art knows how to determine the temperature suitable for melting the agar in the gelling mixture, and also knows how to determine the temperature suitable for solidifying the gelling mixture.

[0046] In one embodiment, the gelling mixture a) mixing water, an attractant, and optionally an omega-3 fatty acid, phospholipids, and / or a colorant; b) Heating the mixture of a); c) During heating, adding agar to the mixture to produce a gelling mixture; It can be prepared by:

[0047] In another embodiment, the gelling mixture is: a1) Mixing water, agar, an attractant, and optionally omega-3 fatty acids, phospholipids, and / or a coloring agent; b1) Heating the mixture of a1) to produce a gelling mixture; It can be prepared by:

[0048] In another embodiment, the gelling mixture is: a2) Mixing water and agar; b2) Adding an attractant and optionally omega-3 fatty acids, phospholipids, and / or a coloring agent to the mixture of a2); c2) Heating the mixture of b2) to produce a gelling mixture; It can be prepared by:

[0049] In another embodiment, the gelling mixture is: a3) Mixing water and agar; b3) Heating the mixture of a3); c3) Adding an attractant and optionally omega-3 fatty acids, phospholipids, and / or a coloring agent to the mixture of b3) to produce a gelling mixture; It can be prepared by:

[0050] The disclosure of the present invention also presents nutritional supplements obtained by any of the preparation methods taught in this application.

[0051] In a third aspect, the disclosure of the present invention more particularly relates to a method of feeding shrimp or fish larvae, which method comprises the step of co-feeding the nutritional supplement taught herein with at least one hydrated or dry feed, such as a hydrated or dry complete feed, to the shrimp or fish larvae. As used herein, a hydrated feed is one that contains more than 10% by weight of water on a wet weight basis. A dry feed contains 10% or less by weight of water on a wet weight basis. Hydrated and dry complete feeds are feeds that contain all of the nutrients necessary for the healthy growth of shrimp or fish at a particular developmental stage. Suitable hydrated and dry feeds are commercially available. One of ordinary skill in the art knows how to select a hydrated or dry feed suitable for co-feeding with the nutritional supplement taught herein.

[0052] In a fourth aspect, the disclosure of the present invention relates to a method of increasing the survival rate of shrimp or fish larvae, which method comprises the step of co-feeding the nutritional supplement taught herein with at least one hydrated or dry feed.

[0053] In a fifth aspect, the disclosure of the present invention more particularly relates to a method of increasing the total biomass of shrimp or fish larvae, which method comprises the step of co-feeding the nutritional supplement taught herein with at least one hydrated or dry feed. This nutritional supplement can be co-fed with at least one hydrated or dry feed during the hatchery phase.

[0054] In a sixth aspect, the disclosure of the present invention relates more particularly to a method of enhancing the growth of shrimp or fish larvae, the method comprising the step of co-feeding a nutritional supplement as taught herein with at least one hydrated or dry feed. This nutritional supplement can be co-fed with at least one hydrated or dry feed during the hatchery phase. The nutritional supplement as taught herein is co-fed with at least one hydrated or dry feed during the hatchery phase, but enhanced growth may be observed during the grow-out phase. Thus, feeding the nutritional supplement as taught herein and at least one hydrated or dry feed is thought to keep the larvae in good health until they pass through the hatchery phase and reach the next stage of development.

[0055] In a seventh aspect, the disclosure of the present invention relates more particularly to a method of reducing bacteria (harmful microorganisms, fungi, viruses, etc.) during the rearing of fish or shrimp larvae, the method comprising the step of co-feeding a nutritional supplement as taught herein with at least one hydrated or dry feed. The reduction of bacteria is compared to the use of live feed. Without wishing to be bound by theory, it is thought that the observed reduction in the number of bacteria during rearing is due to the absence of live feed, which is known to transmit bacteria, during the rearing process.

[0056] In an eighth aspect, the disclosure of the present invention relates more particularly to a method of reducing waste during the rearing of fish or shrimp larvae, the method comprising the step of co-feeding a nutritional supplement as taught herein with at least one hydrated or dry feed.

[0057] In a ninth aspect, the disclosure of the present invention relates more particularly to a nutritional supplement as taught herein for use in enhancing the survival rate of shrimp larvae or fish larvae.

[0058] In a further aspect, the disclosure of the present invention presents the use of a nutritional supplement as taught herein for manufacturing a composition for enhancing the survival rate of shrimp larvae or fish larvae.

[0059] This nutritional supplement and at least one hydrated or dry feed can be fed to shrimp larvae or fish larvae at the same frequency or at different frequencies (e.g., feeding the nutritional supplement to shrimp larvae and fish larvae at a lower frequency than at least one hydrated or dry feed). The amount of the nutritional supplement fed per day varies according to the larval stage of the fish larvae or shrimp larvae. The same is true for the amount of at least one hydrated or dry feed. The nutritional supplement can be fed together with at least one hydrated or dry feed during the hatchery phase.

Examples

[0060] In the examples, it was investigated whether some of the physical characteristics of Artemia could be mimicked with the simplified artificial live feed (ALF) taught in the present application as a nutritional supplement. Furthermore, it was investigated whether all of the Artemia in the larval feed could be replaced with ALF. Still further, it was investigated whether the combined use of a commercially available dry feed (DD) and the nutritional supplement (ALF) taught in the present application would provide a solution alternative to existing rearing strategies for shrimp and / or fish larvae that use Artemia as provided together with the commercially available dry feed.

[0061] To address some of the obstacles associated with the use of live feed, important and beneficial features can be added. Examples include, but are not limited to, the following. · Use of ALF with a larger particle size range compared to live feed · Use of a hygienic and controlled production process in a clinical environment that reduces the biological risks associated with live feed · Use of a product that is readily available, unlike live feed that needs to be upscaled, maintained in a sterile state, and nutrient-enriched · A product that is easy to administer and control in the water column, has natural buoyancy, and is evenly present, compared to live feed that is phototactic, concentrates, grows (Artemia), or even reproduces (Rotifers) and proliferates in the larval shrimp or fish tank

[0062] Since ALF is more than a physical imitation of live food but not a complete feed, it is preferably used within a limited period. Since this is fed together with a dry feed containing all the nutrients required by the larvae, it is considered that even if Artemia is replaced with ALF, feeding deficiencies will not occur. In the examples using P. vannamei, ALF was used at a dose of 0.5 - 3 kg per million shrimp produced during the critical molting period from M3 to PL5. For fish and other shrimp species, ALF may be used during the same or different periods and in the same or different amounts.

[0063] [Feed] The dry feed (DD) used in Examples 1 - 6 below was a commercially available dry feed for feeding shrimp during the molting period from M3 to PL5.

[0064] [ALF] To obtain the artificial live food (ALF) / nutritional supplement taught in the present application, a gelling mixture containing agar, water, marine protein hydrolysate, astaxanthin, DHA, and lecithin was spray - coagulated into granules, which were then wet - sieved to obtain a particle size fraction between 50 - 200 μm. The spray - coagulated granules contained 2% by mass of agar, 5% by mass of an attractant (on a dry matter basis; in the form of marine protein hydrolysate), 0.2% by mass of DHA, 0.5% by mass of lecithin, 0.2% by mass of astaxanthin, and 92.1% by mass of water. These granules were kept in an aqueous salt solution containing NaCl (150 ppt salinity) to obtain a nutritional supplement. The mass ratio of the granules to the aqueous salt solution was 1:1. This nutritional supplement was fed to shrimp larvae as it was. This nutritional supplement (containing granules and aqueous salt solution in a 1:1 mass ratio) contained 78% water, 14% ash, 4% fat, 3% carbohydrates, and approximately 1% protein. The granules were pasteurized at 60 °C for 60 minutes to obtain ALFP.

[0065] [Husbandry] The shrimp tests were conducted 4 times in a 60 L aquarium. As the hatchery phase, nauplii shrimp were introduced at a density of 130 nauplii per liter.

[0066] From Z3 / M1 to PL6, Artemia or ALF was given 6 times a day.

[0067] The water temperature was maintained at 29°C ± 1°C, oxygen at 4.5 mg / L ± 0.5 mg / L, and pH at 8.2 ± 0.2. The water was seawater at its original concentration (35 ppt).

[0068] [Example 1] The test consisted of 4 treatment groups. DD ART: Dry feed and Artemia DD: Dry feed DD ALFP: Dry feed + sterilized ALF DD ALF: Dry feed + ALF

[0069] When the dry feed was given together with Artemia, sterilized ALF, or ALF, the survival rate (Figure 1A) and average weight (Figure 1B) increased compared to those given only the dry feed. No statistically significant difference was found between the DD ART feeding method and the DD ALFP and DD ALF feeding methods. That is, ALFP and ALF are suitable as Artemia substitutes.

[0070] [Example 2] We investigated whether feeding dry feed either with a fixed daily feeding amount (ALFF) or a variable daily feeding amount (ALFV) would affect the results. With ALFF, the same amount was given from M2 to PL4. With ALFV, feeding started with a small amount at Z3 / M1, reached the maximum amount at M3 / PL1, and gradually decreased until PL4. After PL4, only dry feed was given to the larvae. Furthermore, two ALF treatment groups were compared with a treatment group given both Artemia and dry feed (DD ART) and a treatment group given only dry feed (DD). The results are shown in FIGS. 2A - C. The highest survival rate was obtained with those treated with ALF (DD ALFF and DD ALFV), followed by the Artemia treatment group (DD ART). The results of the treatment group given only dry feed (DD) were the worst (FIG. 2A). The weights of the shrimp in the different treatment groups were comparable (FIG. 2B). Considering the total biomass produced by combining the survival rate and weight (FIG. 2C), it became clear that the ALF treatment groups produced better total biomass than the Artemia treatment group and the treatment group given only dry feed.

[0071] [Example 3] After leaving the hatchery (PL12 stage), the shrimp were reared in a grow - out facility for 8 weeks. Two groups of 350 post - larval shrimp were prepared and both were fed the same commercial feed (containing 25% protein and 9% fat) based on the weight of the shrimp according to a fixed feeding schedule.

[0072] [Table 1]

[0073] During this period, no Artemia or ALF was given. This period was used to evaluate the effect of diet treatment (DD ART or DD ALF) during the hatchery phase on the survival rate and biomass gain of the shrimp during the grow - out or growth phase.

[0074] The survival rate (Figure 3A) and average weight (Figure 3B) of shrimp given DD ALF between hatchery phases at the end of the grow-out phase increased compared to shrimp given DD ART between hatchery phases. This indicates that shrimp can be reared without using live feed, and also shows that the survival rate and growth are very good when further growing shrimp in the grow-out and grow-out ponds.

[0075] [Example 4] The hatchery test shown in Example 2 was repeated. This test included four treatment groups (A, B, C, and D), each conducted four times. The same amount of dry feed was given to all treatment groups, and Artemia was supplemented except for treatment group C where Artemia was replaced with ALF.

[0076] All treatment groups had good survival rates until the end of the mysis stage. Surprisingly, animals given Artemia in addition to the complete feed had problems with molting into the post-larval stage, while animals receiving the ALF treatment instead of Artemia had fewer molting problems (Figure 4A). The molting problems led to slow and rapid mortality rates in treatment groups A, B, and D (Figure 4B). At PL5, the total mortality rates of these treatment groups were such, but all test groups in treatment group C survived. Also, animals given ALF in addition to the complete feed reached the PL1 / PL2 stage earlier than animals given Artemia in addition to the complete feed. When this test was ended at PL12, the survival rates of all test groups in treatment group C were almost the same, but in all of the other treatment groups, the shrimp did not survive. This indicates that ALF not only has the property of helping shrimp overcome difficult growth stages, but also provides a more hygienic and controlled production process with fewer biological risks from live feed.

[0077] [Example 5] The UV water filtration of the water tank and the daily pumping volume were increased, and the hatchery test shown in Example 4 was repeated. For each of the four treatment groups (A, B, C, and D), the test was conducted four times again. Treatment groups A and B were given the same dry feed as in Example 4, and treatment groups C and D were given the same dry feed but with different lot numbers.

[0078] The same amount of dry feed was given to all treatment groups, and Artemia was supplemented except for treatment groups B and C (where Artemia was replaced with ALF). The feed consumption calculated per million shrimp produced was 3.5 kg of dry feed, 2 kg of Artemia assist, and 1.3 kg of ALF. The shrimp are difficult to molt when migrating from M3 to PL1, but the survival rate is not affected, and PL12 was produced at a survival rate of 40 - 45% in all treatment groups. During the breeding period from M3 to PL5, when the breeding water sample was plate-cultured in TCBS medium, the presence of Vibrio species was observed. Figure 5A shows that the appearance of Vibrio species on the plate is very prominent in the Artemia treatment group compared to the ALF treatment group. Also, during pumping, more organic deposits from Artemia were seen in treatment groups A and D compared to the treatment group given ALF (Figure 5B). It was shown again that live feed such as Artemia can be replaced with ALF, along with the advantages of reducing the bacterial load and waste during the larval breeding period.

[0079] [Example 6] To find the Vibrio contamination source, a simple test was conducted using beakers filled with seawater without shrimp. The test was conducted three times for five treatment groups. The treatment groups are as follows. · Control (without feed) · Dry feed · Dry feed and ALF · Dry feed and heat-treated Artemia · Dry feed and live Artemia

[0080] The concentration of each bait corresponded to the daily feeding amount. The feed was aerated to keep it in a suspended state. After one day, the precipitate was filtered off, and the content of the filter medium was analyzed by plate culturing three times with TCBS medium. After plate culturing, the number of Vibrio species was counted. In the treatment group containing live Artemia, all three plates turned yellow due to the presence of Vibrio species, but no Vibrio species were detected in the other treatment groups.

[0081]

Table 2

[0082] [Example 7] Furthermore, ALF was given to bass larvae and zebrafish larvae together with a commercial feed (Gemma Micro manufactured by Skretting). As observed by imaging (the presence of ALF in the digestive tract of the larvae can be visually recognized in red, and the presence of Gemma Micro in the digestive tract of the larvae can be visually recognized in green), it was found that ALF was ingested by fish larvae (both bass and zebrafish). The fish larvae were clearly attracted to ALF. From the excrement, it was confirmed that ALF was ingested and digested.

[0083] The foregoing embodiments are for the purpose of explaining the present invention and are not limiting. It should also be noted that those skilled in the art can devise many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The use of the verb “comprise” and its conjugations does not exclude the presence of elements or steps other than those recited in the claims. The article “a” or “an” preceding an element does not exclude the presence of a plurality of these elements.

[0084] Even if a certain method is recited in different dependent claims, it does not indicate that these methods cannot be used in combination to bring out the advantages.

Claims

1. A nutritional supplement suitable for ingestion by shrimp larvae or fish larvae, wherein the nutritional supplement comprises I) a particulate gel structure, and II) an aqueous medium containing at least one salt, and the particulate gel structure comprises a) agar, b) an attractant, and c) water and the particulate gel structure is dispersed in the aqueous medium. A nutritional supplement characterized by the above.

2. The nutritional supplement according to claim 1, characterized in that the nutritional supplement further comprises a component selected from the group consisting of a colorant, omega-3 fatty acids, and phospholipids, or any combination thereof.

3. The nutritional supplement according to claim 2, characterized in that the nutritional supplement contains a colorant, omega-3 fatty acids, and phospholipids.

4. The nutritional supplement according to claim 1, characterized in that the aqueous medium contains at least 80 ppt of salt, preferably at least 80 ppt of sodium chloride.

5. The nutritional supplement according to claim 1, characterized in that the particulate gel structure is in the form of gelled particles, for example granules, preferably having a particle size between 1 μm and 2 mm, more preferably between 5 μm and 800 μm.

6. The nutritional supplement according to claim 1, characterized in that the particulate gel structure, such as in the form of granules, has a density between 0.995 and 1.200 g / mL.

7. The nutritional supplement according to claim 1, characterized in that the gel structure contains agar between 0.01 and 10% by mass on a wet weight basis.

8. The nutritional supplement according to claim 2 or 3, characterized in that the omega-3 fatty acids contain docosahexaenoic acid (DHA).

9. The nutritional supplement according to claim 2 or 3, characterized in that the phospholipids contain lecithin.

10. The nutritional supplement according to claim 2 or 3, characterized in that the colorant is selected from the group consisting of carotenoids (such as carotenes, or preferably xanthophylls), carbon, clay, minerals, anthocyanins, or colored algae (such as red algae, green algae, etc.).

11. The nutritional supplement according to claim 10, characterized in that the colorant is carotene.

12. A nutritional supplement according to claim 10, wherein the colorant is astaxanthin.

13. A nutritional supplement according to claim 1, wherein the aqueous medium contains sodium chloride (NaCl) as a salt, desirably between 100 and 300 ppt of NaCl.

14. A nutritional supplement according to claim 1, wherein the mass ratio of the particulate gel structure to the aqueous medium is between 0.2:1 and 1:0.

2.

15. A method for producing a nutritional supplement suitable for co-feeding to larvae of shrimp or fish, wherein the production method comprises i) coagulating a gelling mixture containing agar, water, and an attractant, and optionally omega-3 fatty acids, phospholipids, and a colorant, to produce a particulate gel structure, such as granules; ii) optionally wet-sieving the particulate gel structure, such as granules, to obtain a particulate gel structure, such as granules, of a suitable size; iii) dispersing the particulate gel structure, such as granules, in an aqueous medium containing at least one salt to obtain a nutritional supplement suitable for ingestion by larvae of shrimp or fish. A production method characterized by including the above steps.

16. A method for feeding larvae of shrimp or fish, wherein the feeding method promotes the growth of larvae of shrimp or fish, increases the total biomass of larvae of shrimp or fish, reduces bacteria during the rearing of larvae of fish or shrimp, and / or reduces waste during the rearing of larvae of fish or shrimp. The feeding method comprises feeding the larvae of shrimp or fish with the nutritional supplement according to claim 1 together with at least one hydrated or dry feed, such as a hydrated or dry complete feed.

17. A feeding method according to claim 16, wherein the nutritional supplement and at least one hydrated or dry feed are fed to the larvae of shrimp or fish at different frequencies such that the nutritional supplement is fed to the larvae of shrimp or fish less frequently than at least one hydrated or dry feed.

18. A feeding method according to claim 16 or 17, wherein the nutritional supplement is fed together with at least one hydrated or dry feed during hatchery phases.

19. The nutritional supplement according to claim 1, characterized by being used non-medically to increase the survival rate of shrimp larvae or fish larvae.

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