A feeding method of a feed for breeding juvenile crayfish

Abstract

The application discloses a kind of crayfish fry culture feed feeding method, the culture feed includes basic feed and additive, and according to following method steps, the additive is fed to crayfish fry: for the crayfish fry that is separated from parent within 30 days, with the growth process of crayfish fry, gradually reduce the mass ratio of camellia saponin in additive;For the crayfish fry that is separated from parent within 30 days, with the growth process of crayfish fry, gradually improve the mass ratio of camellia protein powder relative to camellia saponin.The present application makes full use of the nutritional component characteristics and functional characteristics of defatted camellia kernel powder, camellia protein powder and camellia saponin, so that it matches the characteristics of the growth stage of crayfish fry, provides energy for crayfish fry while also protecting and cleaning the survival environment of crayfish fry, which is conducive to improving the survival rate of crayfish fry and conducive to the growth and development of crayfish.

Description

Technical Field

[0001] This invention belongs to the field of aquaculture, and particularly relates to a method for feeding aquaculture feed. Background Technology

[0002] Crayfish is an important freshwater aquaculture species in my country, and its farming scale and market demand have continued to increase in recent years. However, crayfish farming commonly suffers from problems such as slow growth and weak disease control. In traditional farming, crayfish are often fed chemical growth promoters, which can reduce their quality and safety over time. In particular, there are no specific feed additives for crayfish larvae, making it difficult to meet their growth needs.

[0003] Defatted camellia seed powder, a complex extracted from the kernels of camellia seeds after shelling, possesses biological activities such as promoting growth, regulating immunity, and inhibiting bacteria and repelling parasites, and has broad application potential in animal husbandry. However, existing technologies have not shown the use of defatted camellia seed powder in crayfish farming, let alone in the farming of crayfish larvae. The compatibility between defatted camellia seed powder and crayfish larvae farming is not disclosed or revealed in existing technologies. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the background art above and to provide a feeding method for crayfish seedlings.

[0005] A method for feeding crayfish larvae with a culture feed, wherein the culture feed includes a basic feed and additives, and the additives include a combination of two or three of defatted camellia seed powder, camellia protein powder, and camellia saponin, and the crayfish larvae are fed the additives according to the following steps:

[0006] For crayfish larvae that have been separated from their mothers for 30 days or less (including 30 days), the mass ratio of camellia saponin in the additives is gradually reduced as the crayfish larvae grow and develop. For crayfish larvae that have been separated from their mothers for less than 30 days, the quality ratio of camellia oil protein powder to camellia oil saponin is gradually increased as the larvae grow and develop.

[0007] In the above feeding method, preferably, the camellia protein powder and camellia saponin are fed within 7 days after the crayfish larvae are separated from their mothers, and the defatted camellia kernel powder is fed at least 14 days after the crayfish larvae are separated from their mothers, and the mass ratio of the defatted camellia kernel powder in the additives is gradually increased.

[0008] In the above feeding method, preferably, the additive is fed in steps according to at least the following five stages: within 7 days (including 7 days) after separation from the mother, more than 7 days (excluding 7 days) but less than 14 days after separation from the mother, more than 14 days but less than 20 days after separation from the mother, more than 20 days but less than 30 days after separation from the mother, and more than 30 days but less than 55 days after separation from the mother.

[0009] In the above feeding method, preferably, the additive is fed to the crayfish larvae according to the following steps: Crayfish larvae within 7 days of separation from their mother: The additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, wherein the mass ratio of camellia oleifera protein powder to camellia oleifera saponin is 1-1.5:1; Crayfish larvae that have been separated from their mother for more than 7 days but less than 14 days: The additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, and the mass ratio of camellia oleifera protein powder to camellia oleifera saponin is 2-3:1; Crayfish larvae that have been separated from their mothers for more than 14 days but less than 20 days: The additive is a mixture of defatted camellia seed powder, camellia protein powder and camellia saponin, wherein the mass ratio of defatted camellia seed powder, camellia protein powder and camellia saponin is 0.5-1:3-5:1; Crayfish larvae that have been separated from their mother for more than 20 days but less than 30 days: The additive is a mixture of defatted camellia seed powder and camellia protein powder, wherein the mass ratio of defatted camellia seed powder to camellia protein powder is 1-2:2; Crayfish larvae that have been separated from their mother for more than 30 days but less than 55 days: The additive is a mixture of defatted camellia seed powder and camellia saponin, wherein the mass ratio of defatted camellia seed powder to camellia saponin is 3-5:1; The defatted camellia seed powder is a product obtained by dehulling and oil-controlling the camellia seeds, followed by low-temperature removal of oil from the camellia seed powder using a supercritical carbon dioxide extraction process. The camellia protein powder and camellia saponin are obtained by low-temperature alcohol extraction and separation from the defatted camellia seed powder.

[0010] In the above feeding method, preferably, for crayfish larvae within 14 days of separation from their mother, the mass ratio of the basic feed to the additive is (3-4):1; for crayfish larvae between 14 and 55 days of separation from their mother, the mass ratio of the basic feed to the additive is (6-9):1.

[0011] In the above feeding method, preferably, for crayfish seedlings that have been separated from their mothers for more than 14 days but less than 55 days, the basic feed and the additive are mixed evenly and made into a spherical structure, and the diameter of the spherical structure is 0.3-0.8cm, with a through hole of 0.1-0.15cm in the center, and multiple holes are evenly distributed on the surface of the spherical structure.

[0012] In the above feeding method, preferably, the defatted camellia seed powder is a product obtained by dehulling and oil-controlling the camellia seeds, followed by low-temperature removal of oil from the camellia seed powder using a supercritical carbon dioxide extraction process. The camellia protein powder and camellia saponin are obtained from the defatted camellia seed powder by low-temperature alcohol extraction, including the following steps: (1) Remove the shells from the camellia seeds to obtain camellia kernels, then drain the oil from the camellia kernels, crush them and sieve them to obtain powdered material (i.e. camellia kernel powder). (2) The powdered material is loaded into an extraction vessel and extracted by supercritical carbon dioxide to obtain camellia seed oil and defatted camellia seed powder; (3) The defatted camellia seed powder was subjected to low-temperature alcohol extraction, and the alcohol extract was subjected to solid-liquid separation to obtain camellia protein phase and camellia saponin phase; (4) The tea oil protein phase is dried, pulverized and sieved to obtain tea oil protein powder; the tea oil saponin phase is concentrated and spray dried to obtain tea oil saponin.

[0013] In the above feeding method, preferably, during supercritical carbon dioxide extraction, the extraction pressure is controlled at 35-45 MPa, the extraction temperature at 40-50℃, the extraction time at 2-3 h, and the carbon dioxide flow rate at 2-3 t / h; the pressure of the first-stage separator is 14-16 MPa, and the temperature is 45-55℃; the pressure of the second-stage separator is 9-12 MPa, and the temperature is 40-50℃; the pressure of the third-stage separator is 4-6 MPa, and the temperature is 25-35℃.

[0014] In the above feeding method, preferably, when the defatted camellia seed powder is extracted with alcohol at low temperature, the extractant is an ethanol solution with a concentration of 60%-80%, the material-to-liquid ratio during extraction is 1:(6-10), the extraction temperature is 20-40℃, and the extraction time is 60-120 min; then the alcohol extract is subjected to solid-liquid separation using a filter press, the plate and frame pressure of the filter press is 0.45-0.90 MPa, and the holding time is 20-50 min, to obtain camellia protein phase and camellia saponin phase; The camellia protein phase is dried, pulverized, and sieved to obtain camellia protein powder, including the following steps: drying in a vacuum oven at a vacuum degree of -0.05 to -0.1 MPa and a temperature of 60-70℃ until the moisture content is below 8%; the dried material is pulverized and then sieved through a 20-40 mesh vibrating sieve, and the large particles after sieving are pulverized again until all the material is sieved to obtain camellia protein powder; The camellia saponin phase is concentrated and spray-dried to obtain camellia saponin, including the following steps: double-effect negative pressure evaporation concentration is adopted, the system vacuum degree is controlled at 380-440 mmHg, the first-stage evaporation heating temperature is 60-80℃, the second-stage evaporation heating temperature is 80-90℃, the ethanol solvent is removed and recycled, and finally concentrated to a solid content of 35%-60%; then it is spray-dried, the inlet air temperature of spray drying is 170-210℃, and the outlet air temperature is 85-100℃ to obtain camellia saponin.

[0015] In the above feeding method, preferably, the basic feed comprises the following components in parts by weight: 2-5 parts fish meal, 2-5 parts fish lysate, 2-5 parts shrimp meal, 1-4 parts chicken meal, 2-5 parts blood meal, 3-7 parts 60% cottonseed protein, 15-30 parts 46% soybean meal, 2-8 parts peanut meal, 5-15 parts rapeseed meal and red cake, 2-8 parts distiller's grains, 20-30 parts wheat flour, 5-10 parts rice bran, 1-5 parts soybean lecithin oil, 2-5 parts bentonite, 2-5 parts calcium dihydrogen phosphate, and 0.01-0.05 parts phytosterols.

[0016] The defatted camellia seed powder used in this invention is prepared by dehulling, oil-controlling pulverization, sieving, and low-temperature degreasing of dried camellia seeds using supercritical carbon dioxide extraction technology. Compared with camellia seed cake obtained by traditional pressing and solvent extraction, which is obtained by extracting oil from pressed camellia seed cake, the defatted camellia seed powder used in this invention is a white powder with a honeycomb porous structure and good dispersibility. It also has higher purity and contains core active ingredients such as camellia saponins, crude protein, non-starch polysaccharides, and amino acids. This invention boasts a superior composition, fully preserving heat-sensitive active ingredients such as polyphenols and flavonoids, with no solvent residue. In terms of performance, it exhibits better water solubility, stronger environmental adaptability, and superior biocompatibility, leaving no residue in crayfish after cultivation. In contrast, traditional pressing methods for camellia seed cake and solvent extraction methods result in darker color, a stronger bitter taste, greater loss of heat-sensitive components, a lower proportion of active substances, solvent residue, and the presence of harmful components such as benzo[a]pyrene. These methods also exhibit poor water solubility and environmental stability, posing risks of irritation and residue buildup in the body. This invention replaces traditional chemical growth promoters with natural defatted camellia seed powder, improving the safety and economic benefits of the farmed product. Furthermore, this invention targets the growth characteristics of crayfish larvae, adding different additives at different growth stages, which is more conducive to the growth and development of crayfish larvae and improves their survival rate. Analysis is as follows: For crayfish larvae within 30 days of separation from their mother, the proportion of camellia oil saponin in the feed additive should be gradually reduced while the proportion of camellia oil protein powder relative to camellia oil saponin should be gradually increased as the larvae grow and develop. As the larvae grow, their protein requirements gradually increase, and they are more likely to consume the feed completely, thus reducing the impact of leftover feed on water quality. Therefore, the amount of camellia oil saponin can be gradually reduced. Once the crayfish larvae have been separated from their mother for at least 14 days, defatted camellia oil kernel powder, which has a more complete nutritional profile, can be added, with its content gradually increased thereafter. However, it is not advisable to add defatted camellia oil kernel powder too early, as this can easily cause anorexia in the crayfish larvae and affect their growth and development.

[0017] In a more preferred embodiment, the feed additive is administered in stages according to at least the following five phases: within 7 days of weaning, 7 to 14 days after weaning, 14 to 20 days after weaning, 20 to 30 days after weaning, and 30 to 55 days after weaning. Specific analysis follows: For crayfish larvae within 7 days of separation from their mother, the main additive is a small amount of camellia oleifera protein powder, supplemented with a small amount of camellia oleifera saponin (the mass ratio of camellia oleifera protein powder to camellia oleifera saponin is 1-1.5:1). Since the larvae at this stage have weak feeding ability, the small amount of camellia oleifera protein powder provides them with nutrients, while the addition of a small amount of camellia oleifera saponin promotes the survival of the crayfish. Camellia oleifera saponin also has a bactericidal effect, ensuring the cleanliness of the food and preventing spoilage, thus helping to maintain good water quality. At this stage, the synergistic use of camellia oleifera protein powder and camellia oleifera saponin significantly improves the survival rate of the larvae compared to feeding them camellia oleifera protein powder or camellia oleifera saponin alone. Feeding camellia oleifera protein powder alone can lead to increased ammonia nitrogen levels due to its easy degradation if not consumed, thus affecting the survival of the crayfish larvae. Feeding camellia oleifera saponin alone results in a lack of nutrients required for the growth and development of the crayfish. Defatted camellia seed powder should not be used as an additive at this stage, because defatted camellia seed powder has a bitter taste and poor solubility, which is not conducive to the consumption of small seedlings, and is not conducive to their growth, development and survival.

[0018] For crayfish larvae that have been separated from their mothers for 7 to 14 days, the additive mainly consists of a small amount of camellia oleifera protein powder, along with a small amount of camellia oleifera saponin (the mass ratio of camellia oleifera protein powder to camellia oleifera saponin is 2-3:1). At this stage, the larvae have independent feeding capabilities and need to develop their swimming ability in the water, which requires a certain amount of physical exertion. They need more protein than the larvae in the previous stage. Therefore, the amount of camellia oleifera protein powder used is increased compared to the previous stage. At the same time, in order to ensure the survival rate of the larvae and to maintain water quality, camellia oleifera saponin is added in combination.

[0019] For crayfish larvae that have been separated from their mothers for 14 to 20 days, the additive consists of a mixture of defatted camellia seed powder, camellia protein powder, and camellia saponin (mass ratio 0.5-1:3-5:1). At this growth stage, the larvae have increased climbing ability and feeding capacity. Therefore, the proportion of camellia protein powder in the additive is further increased to provide more nutrients. A small amount of camellia saponin is also added to ensure larvae survival and water quality. More importantly, a small amount of defatted camellia seed powder is added at this stage. The defatted camellia seed powder contains small amounts of polysaccharides, saponins, tannins, and phenols, further supplementing the larvae's energy. The amount of defatted camellia seed powder should not be excessive, otherwise it will significantly alter the taste and affect the crayfish larvae's feeding.

[0020] For crayfish larvae that have been separated from their mothers for 20 to 30 days, the additive is a mixture of defatted camellia seed powder and camellia protein powder (mass ratio 1-2:2). At this growth stage, the larvae have stronger climbing abilities and higher food requirements. Therefore, a mixture of defatted camellia seed powder and camellia protein powder, both rich in nutrients, is used. The various nutrients in the defatted camellia seed powder help supplement energy, while the camellia protein powder provides a large amount of protein, promoting the growth and development of the crayfish. Furthermore, the amount of defatted camellia seed powder is increased at this stage, and the camellia protein powder should not be omitted, otherwise it will significantly change the taste of the feed and affect the crayfish's feeding. At this stage, the crayfish larvae's feeding ability is significantly enhanced, and there is less food residue. The water purification ability of the defatted camellia seed powder is sufficient to maintain water quality, and the addition of camellia saponin is unnecessary.

[0021] For crayfish larvae that have been separated from their mothers for more than 30 days but less than 55 days, the additive is a mixture of defatted camellia seed powder and camellia saponin (mass ratio of 3-5:1). During this growth stage, the additive is mainly defatted camellia seed powder, which provides the nutrients needed for the growth and development of the crayfish by utilizing the fact that defatted camellia seed powder is rich in various nutrients. At this stage, it is also necessary to focus on regulating the crayfish's immunity, so a small amount of camellia saponin is added as a supplement. Camellia saponin can also adjust the changes in taste caused by a large amount of defatted camellia seed powder and promote the crayfish's feeding.

[0022] Based on the above-mentioned crayfish seedlings at different growth and development stages, this invention also optimizes the ratio of additives and basic feed. For crayfish seedlings within 14 days of separation from the mother, the mass ratio of basic feed to additives is (3-4):1; for crayfish seedlings between 14 and 55 days of separation from the mother, the amount of additives is increased, making the mass ratio of basic feed to additives (6-9):1, which is more conducive to the growth and development of crayfish and improves the survival rate.

[0023] This invention addresses the varying nutritional needs of crayfish larvae at different growth and development stages. Based on the larvae's mobility and the properties of defatted camellia seed powder, camellia protein powder, and camellia saponin, different additive combinations are used for each stage. This provides nutrients while regulating the crayfish's immunity and ensuring water quality meets requirements. This optimization process represents the first attempt at using camellia extract in crayfish farming, and the selection of suitable camellia extract combinations for different growth stages fills a gap in existing technology.

[0024] Our further research revealed that crayfish exhibit varying feeding abilities at different growth stages. Very young crayfish, in particular, have weak claws and lack climbing strength, making them prone to death due to insufficient food or poor feeding ability. To address this issue, this invention employs different feeding methods for crayfish at different growth stages. For crayfish larvae within 14 days of separation from their mother, feed is evenly scattered. At this stage, their climbing ability is weak, and evenly dispersing the feed in the water facilitates dispersed feeding. For crayfish larvae between 14 and 55 days of separation from their mother, the basic feed and additives are mixed evenly and formed into spherical structures with a diameter of 0.3-0.8 cm and a 0.1-0.15 cm through-hole in the center. At this stage, the crayfish larvae possess some climbing ability and can attach to the spherical feed spheres to feed. In a more preferred design, perforations are made in the spherical feed pellets, and multiple holes are created on the surface of the feed pellets. This is more conducive to crayfish feeding. The specific analysis is as follows: Crayfish do not use their first pair of claws to pick up food; instead, they gently grasp the food with their second pair. The second pair of claws is relatively weaker than the first pair, and if it is inconvenient during crawling, it can easily become strenuous, or even break, which is fatal to crayfish. If the feed is changed to a perforated spherical shape, firstly, the roundness and lack of sharp edges make it easier for the crayfish to grasp and eat it. The holes provide a foothold for the crayfish to climb, allowing them to hold onto the food tightly. Secondly, the perforated spherical feed increases the contact area between the crayfish and the feed, accelerating feeding. Furthermore, the perforated feed pellets make it easier for crayfish to gather together and grasp the food, preventing fights and deaths among crayfish due to the small size of the food particles. Furthermore, spherical perforated feed is less likely to disperse when added to water, which helps improve feed utilization and water quality stability. Our data analysis shows that, for the same feed formulation, the intake rate of spherical perforated feed is higher than that of cylindrical pellets.

[0025] Compared with the prior art, the advantages of the present invention are as follows: The feeding method for crayfish larvae rearing feed of the present invention selectively adds two or three of the following to the basic feed: defatted camellia seed powder, camellia protein powder, and camellia saponin. This adapts the feed to crayfish larvae at different growth and development stages, fully utilizing the nutritional and functional properties of these ingredients to match the characteristics of the crayfish larvae's growth and development. While providing energy, this method also protects and cleans the crayfish larvae's living environment, improving their survival rate and promoting their growth and development. This crayfish larvae rearing feed fills the gap in the use of camellia extract in crayfish larvae rearing, avoids the problem of chemical additive residues, improves the safety and economic benefits of the reared products, and can be directly applied to large-scale ecological crayfish larvae rearing, possessing significant promotional and application value. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart illustrating the preparation process of defatted camellia seed powder according to the present invention.

[0028] Figure 2 This is a flowchart illustrating the preparation process of camellia oleifera protein powder and camellia oleifera saponin according to the present invention.

[0029] Figure 3 This is a photograph of the defatted camellia seed powder of the present invention.

[0030] Figure 4 This is a photograph of the actual product of the camellia protein powder of the present invention.

[0031] Figure 5 This is a photograph of the actual product containing the camellia saponin of the present invention.

[0032] Figure 6 This is a photograph of the feed after it has been formed into clumps and perforated according to the present invention. Detailed Implementation

[0033] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0034] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0035] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0036] Example 1: A method for feeding crayfish larvae, comprising a basal feed and additives, the additives being a combination of defatted camellia seed powder, camellia protein powder, and camellia saponin. The method involves feeding the crayfish larvae with the additives according to the following steps: For crayfish larvae within 30 days of separation from their mother, the proportion of camellia saponin in the additives is gradually reduced as the larvae grow; for crayfish larvae within 30 days of separation from their mother, the proportion of camellia protein powder relative to camellia saponin is gradually increased as the larvae grow. Camellia protein powder and camellia saponin are started within 7 days of separation from the mother, while defatted camellia seed powder is started at least 14 days after separation, with the proportion of defatted camellia seed powder in the additives gradually increased.

[0037] In this embodiment, more specifically, the additive is fed in stages according to at least the following five phases: within 7 days of separation from the mother, 7 to 14 days after separation from the mother, 14 to 20 days after separation from the mother, 20 to 30 days after separation from the mother, and 30 to 55 days after separation from the mother. The additive is specifically fed to the crayfish larvae according to the following methods and steps: For crayfish larvae within 7 days of separation from their mother: the additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, with a mass ratio of 1:1. For crayfish larvae between 7 and 14 days of separation from their mother: the additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, with a mass ratio of 2:1. For both stages, the mass ratio of basal feed to additive is 3:1.

[0038] For crayfish larvae separated from their mothers for 14 to 20 days: the additive is a mixture of defatted camellia seed powder, camellia protein powder, and camellia saponin, with a mass ratio of 0.6:3:1. For crayfish larvae separated from their mothers for 20 to 30 days: the additive is a mixture of defatted camellia seed powder and camellia protein powder, with a mass ratio of 1:2. For crayfish larvae separated from their mothers for 30 to 55 days: the additive is a mixture of defatted camellia seed powder and camellia saponin, with a mass ratio of 4:1. In all three stages, the mass ratio of basal feed to additives is 8:1.

[0039] In this embodiment, defatted camellia seed powder is a product obtained by dehulling and oil-controlling the camellia seeds, followed by low-temperature removal of oil from the camellia seed powder using supercritical carbon dioxide extraction technology. Camellia protein powder and camellia saponin are products obtained from defatted camellia seed powder through low-temperature alcohol extraction. Figure 1 , Figure 2 As shown, the specific extraction method is as follows: (1) Raw material pretreatment: Select dried camellia seeds as raw materials, and obtain uniform powder materials by shelling, oil control crushing, and sieving through a 60-mesh screen (the raw materials that fail to pass the screen are crushed again until all are sieved). (2) Supercritical carbon dioxide extraction for oil removal: Weigh 260 kg of pretreated powder material and load it into a 750 L extraction vessel. Control the extraction pressure at 42 MPa and the extraction temperature at 42 °C. The pressure and temperature of the first separation vessel are 16 MPa and 50 °C, the pressure and temperature of the second separation vessel are 9 MPa and 44 °C, and the pressure and temperature of the third separation vessel are 6 MPa and 30 °C. The carbon dioxide flow rate is 2-3 t / h. Continue extraction for 3 h. After extraction, collect the camellia seed oil (golden color, fragrant aroma, clear and transparent liquid without any off-odors) obtained from separation vessel one, separation vessel two, and separation vessel three. The remaining material in the extraction vessel is the defatted camellia seed powder (residual oil rate 1.2%, moisture content 5.85%). Figure 3 (As shown).

[0040] (3) The defatted camellia seed powder was subjected to low-temperature alcohol extraction. The extractant was an ethanol solution with a mass concentration of 70%. The material-to-liquid ratio during extraction was 1g:8mL. The extraction temperature was 35℃ and the extraction time was 80min. During solid-liquid separation of the alcohol extract, the pressure of the filter press plate and frame was 0.90MPa and the holding time was 30min. After solid-liquid separation, camellia protein phase and camellia saponin phase were obtained.

[0041] (4) The camellia protein phase was dried in a vacuum oven at -0.1 MPa and 65°C until the moisture content was below 8%. The dried material was then pulverized and sieved through a 30-mesh vibrating sieve. Large particles were pulverized again until all the material passed through the sieve to obtain camellia protein powder (crude protein content 20.22%, total sugar content 31.66%, moisture content 8.29%). Figure 4 (As shown).

[0042] (5) The camellia saponin phase was concentrated by double-effect negative pressure evaporation. The system vacuum was controlled at 400 mmHg. The first-stage evaporation heating temperature was 70℃, and the second-stage evaporation heating temperature was 80℃. The ethanol solvent was removed and recycled. Finally, the solution was concentrated to a solid content of 40%. Then, it was spray-dried. The inlet air temperature of the spray dryer was 190℃, and the outlet air temperature was 90℃ to obtain camellia saponin (camellia saponin content 62.18%, moisture content 5.06%, pH value 6.2, etc.). Figure 5 (As shown).

[0043] In this embodiment, the basic feed includes the following components in parts by weight: 4 parts fish meal, 3 parts fish solubles, 3 parts shrimp meal, 2 parts chicken meal, 3 parts blood meal, 5 parts 60% cottonseed protein, 20 parts 46% soybean meal, 5 parts peanut meal, 10 parts rapeseed meal and red cake, 6 parts distiller's grains, 23 parts wheat flour, 8.47 parts rice bran, 2 parts soybean lecithin oil, 1 part premix, 2.3 parts bentonite, 2.2 parts calcium dihydrogen phosphate, and 0.03 parts phytosterols.

[0044] The aforementioned blood meal is a high-quality protein feed, made from animal blood collected in slaughterhouses or processing plants through processes such as high-temperature and high-pressure treatment, membrane breaking, decolorization, and low-temperature drying (manufacturer: Jinan Mengshi Weiye Chemical Co., Ltd., model TGV975212). The aforementioned premix is ​​the core of complete feed, consisting of one or more feed additive ingredients and a carrier, mixed evenly. It cannot be directly fed to animals and is a high-tech product of the feed industry (manufacturer: Jiangsu Liangyou Zhengda, model SFYH500).

[0045] Example 2: The feeding method for crayfish larvae in this embodiment is similar to that in Embodiment 1, except that the additives are fed to the crayfish larvae according to the following steps: For crayfish larvae within 7 days of separation from their mother: the additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, with a mass ratio of 1.5:1. For crayfish larvae between 7 and 14 days of separation from their mother: the additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, with a mass ratio of 2.5:1. In both stages, the mass ratio of basal feed to additive is 3.5:1.

[0046] For crayfish larvae separated from their mothers for 14 to 20 days: the additive is a mixture of defatted camellia seed powder, camellia protein powder, and camellia saponin, with a mass ratio of 0.8:4:1. For crayfish larvae separated from their mothers for 20 to 30 days: the additive is a mixture of defatted camellia seed powder and camellia protein powder, with a mass ratio of 2:2. For crayfish larvae separated from their mothers for 30 to 55 days: the additive is a mixture of defatted camellia seed powder and camellia saponin, with a mass ratio of 5:1. In all three stages, the mass ratio of basal feed to additives is 7:1.

[0047] The other conditions in this embodiment are the same as in Embodiment 1.

[0048] Comparative Example 1: The main difference between this comparative example and Example 1 is that the additive used for crayfish seedlings at all stages is defatted camellia seed powder, while the other conditions are the same as in Example 1.

[0049] Comparative Example 2: The main difference between this comparative example and Example 1 is that the additive used for crayfish seedlings at all stages is tea oil protein powder, while the other conditions are the same as in Example 1.

[0050] Comparative Example 3: The main difference between this comparative example and Example 1 is that for crayfish larvae within 7 days of separation from the mother, the additive is camellia oleifera protein powder; for crayfish larvae between 7 and 14 days of separation from the mother, the additive is camellia oleifera protein powder. Other conditions are the same as in Example 1.

[0051] Comparative Example 4: The main difference between this comparative example and Example 1 is as follows: For crayfish larvae that have been separated from their mothers for 14 to 20 days: the additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, with a mass ratio of 3.6:1; for crayfish larvae that have been separated from their mothers for 20 to 30 days: the additive is camellia oleifera protein powder; for crayfish larvae that have been separated from their mothers for 30 to 55 days: the additive is defatted camellia oleifera kernel powder. All other conditions are the same as in Example 1.

[0052] Comparative Example 5: The main difference between this comparative example and Example 1 is that the crayfish larvae, which were separated from their mothers for more than 14 days but less than 20 days, were used as additives. The additives were a mixture of defatted camellia seed powder, camellia protein powder, and camellia saponin, with a mass ratio of 3:3:1. Other conditions were the same as in Example 1.

[0053] Comparative Example 6: The main difference between this comparative example and Example 1 is as follows: For crayfish larvae within 7 days of separation from the mother: the additive is camellia saponin; for crayfish larvae between 7 and 14 days of separation from the mother: the additive is defatted camellia kernel powder; for crayfish larvae between 14 and 20 days of separation from the mother: the additive is a mixture of defatted camellia kernel powder and camellia saponin, with a mass ratio of defatted camellia kernel powder to camellia saponin of 3.6:1; for crayfish larvae between 20 and 30 days of separation from the mother: the additive is defatted camellia kernel powder; for crayfish larvae between 30 and 55 days of separation from the mother: the additive is a mixture of camellia protein powder and camellia saponin, with a mass ratio of camellia protein powder to camellia saponin of 4:1. All other conditions are the same as in Example 1.

[0054] Comparative Example 7: Compared to Example 1, this comparative example did not contain any additives, only a basic feed. All other conditions were the same as in Example 1.

[0055] The crayfish farming experiment was conducted using the crayfish larvae farming feed from the above embodiments and comparative examples, as detailed below: (1) Shrimp source: Shrimp seedlings (SPF) without specific pathogens were obtained from the breeding and testing of the Aquatic Product Variety Creation Center Laboratory of Yuelushan Laboratory, College of Life Sciences, Hunan Normal University. The selected juvenile shrimp that had just separated from the mother (the selected juvenile shrimp were observed to be swimming independently from the mother's abdomen) were uniform in size, without broken limbs, without black spots, and with strong vitality. They were weighed and counted uniformly in groups to eliminate interference from individual differences.

[0056] (2) Culture environment: pH is maintained between 6.5 and 8.0, water temperature is kept constant between 25 and 28℃, dissolved oxygen value is above 5.0, white water basins are used for culture, with a size of 40×30×10cm, 30 shrimp larvae are placed in each white basin, and 3 parallel replicates are performed, with an initial weight of 0.050±0.015g.

[0057] (3) Feeding method: Feed regularly and in fixed quantities every day. Feeding starts at 8:00 AM and ends at 3:00 PM. Feed 3% of the body weight of the shrimp. Clean up any uneaten food and excrement from the previous day to ensure water quality meets standards. Use a thermometer to check the water temperature daily to ensure it is stable at 25-28℃. If the temperature is abnormal, change the water promptly. Before feeding each day, use a straw to remove uneaten food and shrimp larvae metabolites from the water basin. Adjust the feeding amount according to the amount of metabolites in each group.

[0058] (4) Data statistics: The shrimp's whitening is often due to insufficient food, environmental stress, low dissolved oxygen, or decreased bodily activity caused by fighting among individuals; the shrimp's reddening is often due to hypoxic stress, excessive uneaten food leading to excessive ammonia nitrogen and nitrite levels. Daily records were kept of the feeding status, molting status, and mortality rate of each group of shrimp larvae. After the experiment, the surviving shrimp larvae in each group were weighed, the average weight was calculated, and the weight change data were recorded.

[0059] Aquaculture Experiment 1: The additives in Example 1 were fed to the animals in the following five ways: Method 1: At all stages, mix the basic feed and additives evenly and then scatter and feed them directly. Method 2: For crayfish larvae that have been separated from their mother for less than 14 days, mix the basic feed and additives evenly and then scatter the mixture directly to feed them. For crayfish larvae that have been separated from their mother for more than 14 days but less than 55 days, mix the basic feed and additives evenly and then form a spherical structure with a diameter of 0.8 cm, but do not open the center hole.

[0060] Method 3: For crayfish larvae within 14 days of separation from their mother, mix the basic feed and additives evenly and then scatter the mixture directly onto the crayfish. For crayfish larvae between 14 and 55 days of separation from their mother, mix the basic feed and additives evenly and then form a spherical structure with a diameter of 0.8 cm. The spherical structure should have a 0.1 cm through-hole in the center, and multiple holes on its surface (e.g., ...). Figure 6 (As shown).

[0061] Method 4: In all stages, the basic feed and additives are mixed evenly and then formed into a spherical structure with a diameter of 0.8cm. A through hole of 0.1cm is opened in the center, and multiple holes are opened on the surface of the spherical structure.

[0062] Method 5: For crayfish larvae that have been separated from their mother for less than 14 days, mix the basic feed and additives evenly and then scatter the mixture directly to feed them. For crayfish larvae that have been separated from their mother for more than 14 days but less than 55 days, mix the basic feed and additives evenly and then form a cylindrical structure with a diameter of 0.8 cm and a height of 2 cm, without making a central hole.

[0063] The above method for mixing the basic feed and additives evenly to form a spherical structure is as follows: First, mix the basic feed and additives evenly, then add egg white and continue mixing to make the basic feed and additives evenly bond together. Then, put the bonded material into a molding mold and press it to obtain a ball-shaped structure. Finally, use a metal needle to make a through hole in the center, and use a syringe needle to make multiple small holes around the ball to make a ball-shaped open-pore structure feed.

[0064] The experimental results of the above five feeding methods are shown in Table 1 below: Table 1: Test results of the additive in Example 1 using five different feeding methods

[0065] In the table above, the average survival rate is calculated using the average number of survivors in the experimental group, and the average weight gain is calculated by subtracting the initial average weight of all individuals in the experimental group from the final surviving weight. The average value is taken for multiple parallel experimental groups.

[0066] As shown in Table 1, feeding method three, which involves pelleting and perforating the feed in stages, resulted in the highest survival rate and most significant weight gain for crayfish larvae. Feeding method one, which did not involve pelleting at any stage, resulted in low survival rates and low weight gain for the larvae. Feeding method two, which involved pelleting the feed in stages but without creating central holes, performed better than method one but worse than method three, indicating that creating central holes is beneficial for improving the survival rate and weight gain of the larvae. Feeding method four, which also involved pelleting and perforating crayfish larvae within 14 days of separation from their mothers, actually reduced the survival rate and weight gain of the larvae. This may be related to the low survival rate and minimal weight gain of larvae within 14 days of separation. Using feeding method five, the feed is made into a cylindrical shape. Its performance data is significantly worse than that of feeding method three. This shows that the ball-making and perforation method of the present invention is beneficial to the growth and development of crayfish seedlings.

[0067] Meanwhile, water quality was also monitored in this experiment. The results showed that the water quality was clearest with feeding method three, and ammonia nitrogen levels were less likely to exceed the standard. The water quality was also relatively clear with feeding method two. The water quality was poor in the early stages of feeding method four, but became clearer in the later stages. The water quality was poor in the later stages of feeding method five, and ammonia nitrogen levels were prone to exceed the standard. The water quality was very poor in the later stages of feeding method one, and ammonia nitrogen levels remained above the standard for a long period.

[0068] Aquaculture Experiment 2: For the additives in Example 2 and Comparative Examples 1-7, the crayfish were raised according to feeding method 3 in the first breeding experiment: that is, for crayfish larvae within 14 days of separation from the mother, the basic feed and additives were mixed evenly and then directly scattered and fed; for crayfish larvae between 14 and 55 days of separation from the mother, the basic feed and additives were mixed evenly and then made into a spherical structure with a diameter of 0.8 cm, with a 0.1 cm through hole in the center, and multiple holes on the surface of the spherical structure.

[0069] The experimental results are shown in Table 2 below: Table 2: Test results of additives in Examples 2 and Comparative Examples 1-7

[0070] As shown in the table above, the survival rate and weight gain of the crayfish in Example 2 were similar to those in Example 1. In Comparative Example 1, the additive used in all stages was defatted camellia seed powder. This additive is not suitable for all larval growth stages, resulting in poor survival rate and weight gain, significantly lower than in Example 1. In Comparative Example 2, the additive used in all stages was camellia protein powder. Camellia protein powder alone is also unsuitable for all larval growth stages, leading to poor survival rate and weight gain, significantly lower than in Example 1. Adjusting the additives for certain growth stages in Comparative Examples 3, 4, and 6 did not improve survival rate and weight gain; these were still significantly lower than in Example 1. Adjusting the mass ratio of defatted camellia seed powder, camellia protein powder, and camellia saponin in the additives for crayfish larvae separated from their mothers (14-20 days after birth) in Comparative Example 5 also resulted in lower survival rate and weight gain compared to Example 1. Comparative Example 7, with no additives added, had the worst survival rate and weight gain, significantly lower than in Example 1.

[0071] Safety verification test: Camellia oleifera saponin is toxic to fish. To verify its safety in the application of camellia larvae, this embodiment also conducted a laboratory study on the effects of different concentrations of camellia oleifera saponin on the growth of crayfish larvae (weighing approximately 0.08g). In the laboratory, 50 larvae were stocked in each culture basin (35×25×7cm). Uneaten food and excrement were removed daily in the morning, noon, and evening for meticulous management. Seven concentration gradients of camellia oleifera saponin in the water were set up: 0 (blank control), 10mg / L, 20mg / L, 30mg / L, 40mg / L, 50mg / L, and 60mg / L (concentration unit "mg / L" refers to the mass fraction of camellia oleifera saponin per liter of water). A 56-day observation experiment was conducted, recording changes in body length and weight (Tables 3 and 4), survival rate fluctuations (Table 5), and molting behavior of the crayfish larvae under different concentrations of camellia oleifera saponin. The results are shown below: Table 3: Changes in body length and growth rate of crayfish larvae under different concentrations of camellia saponin treatment.

[0072] Table 4: Changes in average body weight (g) of crayfish larvae treated with different concentrations of camellia saponin.

[0073] Table 5: Survival of crayfish larvae treated with different concentrations of camellia saponin

[0074] A 56-day aquaculture observation experiment yielded the following conclusions: Camellia oleifera saponin, within a concentration range of 10-30 mg / L, significantly increased the weight gain and body length growth rate of crayfish larvae. The 20 mg / L treatment group showed the most pronounced growth-promoting effect (Tables 3 and 4), significantly higher than the control group. The high-concentration camellia oleifera saponin groups (40-60 mg / L) exhibited growth indicators similar to the control group, showing no significant promoting or inhibiting effects (Tables 3 and 4). The survival rate of the experimental groups ranged from 50% to 54%, while the survival rate of the control group was 49% (Table 5), indicating no significant difference in survival rates among the different camellia oleifera saponin concentration groups or between the experimental and control groups. The experimental concentrations of camellia oleifera saponin did not cause specific mortality in crayfish larvae. Thanks to meticulous management, both the experimental and control groups had high survival rates; however, due to high stocking densities, the weight gain of both groups was relatively low. Observations of molting behavior revealed that the 20 mg / L treatment group had the highest total number of molts (average 186 times), significantly higher than the blank control group (140 times).

[0075] The above conclusions indicate that tea oil saponins are essentially non-toxic to shrimp, possibly due to the following reasons: The main differences between fish and shrimp lie in their physiological structures and blood compositions. Regarding physiological structure, the gill epidermis of crayfish is composed of chitin and protein, unlike the gill structure of fish, making it difficult for tea oil saponins to damage the gill tissue of crayfish. Regarding blood composition, the oxygen-carrying carrier in fish blood is heme (containing Fe²⁺). + The oxygen-carrying carrier in crayfish is hemocyanin (containing Cu²⁺). + Tea saponins primarily damage red blood cells, causing them to dissolve in fish, thus killing various wild fish such as loaches. However, they are very weakly toxic to shrimp and can promote shrimp molting.

Claims

1. A method for feeding crayfish larvae, wherein the feed comprises a basic feed and additives, characterized in that, The additive includes two or a combination of two or three of the following: defatted camellia seed powder, camellia protein powder, and camellia saponin. The crayfish larvae are fed the additive according to the following steps: For crayfish larvae that have been separated from their mothers for less than 30 days, the mass ratio of camellia saponin in the additives is gradually reduced as the larvae grow and develop. For crayfish larvae that have been separated from their mothers for less than 30 days, the quality ratio of camellia oil protein powder to camellia oil saponin is gradually increased as the larvae grow and develop.

2. The feeding method according to claim 1, characterized in that, The camellia protein powder and camellia saponin are fed to crayfish larvae within 7 days after they are separated from their mothers, while the defatted camellia kernel powder is fed to crayfish larvae at least 14 days after they are separated from their mothers, and the proportion of defatted camellia kernel powder in the additives is gradually increased.

3. The feeding method according to claim 2, characterized in that, The additive shall be fed in stages according to at least the following five phases: within 7 days after separation from the mother, 7 to 14 days after separation from the mother, 14 to 20 days after separation from the mother, 20 to 30 days after separation from the mother, and 30 to 55 days after separation from the mother.

4. The feeding method according to claim 3, characterized in that, The additive is fed to crayfish larvae according to the following steps: Crayfish larvae within 7 days of separation from their mother: The additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, wherein the mass ratio of camellia oleifera protein powder to camellia oleifera saponin is 1-1.5:1; Crayfish larvae that have been separated from their mother for more than 7 days but less than 14 days: The additive is a mixture of camellia oleifera protein powder and camellia oleifera saponin, and the mass ratio of camellia oleifera protein powder to camellia oleifera saponin is 2-3:

1. Crayfish larvae that have been separated from their mothers for more than 14 days but less than 20 days: The additive is a mixture of defatted camellia seed powder, camellia protein powder and camellia saponin, wherein the mass ratio of defatted camellia seed powder, camellia protein powder and camellia saponin is 0.5-1:3-5:1; Crayfish larvae that have been separated from their mother for more than 20 days but less than 30 days: The additive is a mixture of defatted camellia seed powder and camellia protein powder, wherein the mass ratio of defatted camellia seed powder to camellia protein powder is 1-2:2; Crayfish larvae that have been separated from their mother for more than 30 days but less than 55 days: The additive is a mixture of defatted camellia seed powder and camellia saponin, wherein the mass ratio of defatted camellia seed powder to camellia saponin is 3-5:1; The defatted camellia seed powder is a product obtained by dehulling and oil-controlling the camellia seeds, followed by low-temperature removal of oil from the camellia seed powder using a supercritical carbon dioxide extraction process. The camellia protein powder and camellia saponin are obtained by low-temperature alcohol extraction and separation from the defatted camellia seed powder.

5. The feeding method according to claim 4, characterized in that, For crayfish larvae that have been separated from their mothers for less than 14 days, the mass ratio of the basic feed to the additive is (3-4):1; for crayfish larvae that have been separated from their mothers for more than 14 days but less than 55 days, the mass ratio of the basic feed to the additive is (6-9):

1.

6. The feeding method according to claim 4, characterized in that, For crayfish larvae that have been separated from their mothers for more than 14 days but less than 55 days, the basic feed and the additives are mixed evenly and made into a spherical structure with a diameter of 0.3-0.8 cm and a through hole of 0.1-0.15 cm in the center. Multiple holes are evenly distributed on the surface of the spherical structure.

7. The feeding method according to any one of claims 1-6, characterized in that, The defatted camellia seed powder is a product obtained by dehulling and oil-controlling camellia seeds, followed by low-temperature removal of oil from the camellia seed powder using supercritical carbon dioxide extraction. The camellia protein powder and camellia saponin are obtained from the defatted camellia seed powder by low-temperature alcohol extraction, including the following steps: (1) Remove the shells from the camellia seeds to obtain camellia kernels, then drain the oil from the camellia kernels, crush them, and sieve them to obtain powdered material; (2) The powdered material is loaded into an extraction vessel and extracted by supercritical carbon dioxide to obtain camellia seed oil and defatted camellia seed powder; (3) The defatted camellia seed powder was subjected to low-temperature alcohol extraction, and the alcohol extract was subjected to solid-liquid separation to obtain camellia protein phase and camellia saponin phase; (4) The tea oil protein phase is dried, pulverized and sieved to obtain tea oil protein powder; the tea oil saponin phase is concentrated and spray dried to obtain tea oil saponin.

8. The feeding method according to claim 7, characterized in that, During supercritical carbon dioxide extraction, the extraction pressure is controlled at 35-45 MPa, the extraction temperature at 40-50℃, the extraction time at 2-3 h, and the carbon dioxide flow rate at 2-3 t / h. The pressure of the first-stage separation vessel is 14-16 MPa, and the temperature is 45-55℃; the pressure of the second-stage separation vessel is 9-12 MPa, and the temperature is 40-50℃; the pressure of the third-stage separation vessel is 4-6 MPa, and the temperature is 25-35℃.

9. The feeding method according to claim 7, characterized in that, During the low-temperature alcohol extraction of defatted camellia seed powder, the extractant is an ethanol solution with a concentration of 60%-80%, the material-to-liquid ratio is 1:(6-10), the extraction temperature is 20-40℃, and the extraction time is 60-120 min. The alcohol extract is then subjected to solid-liquid separation using a filter press with a plate and frame pressure of 0.45-0.90 MPa and a holding time of 20-50 min, yielding camellia protein phase and camellia saponin phase. The camellia protein phase is dried, pulverized, and sieved to obtain camellia protein powder, including the following steps: drying in a vacuum oven at a vacuum degree of -0.05 to -0.1 MPa and a temperature of 60-70℃ until the moisture content is below 8%; the dried material is pulverized and then sieved through a 20-40 mesh vibrating sieve, and the large particles after sieving are pulverized again until all the material is sieved to obtain camellia protein powder; The camellia saponin phase is concentrated and spray-dried to obtain camellia saponin, including the following steps: double-effect negative pressure evaporation concentration is adopted, the system vacuum degree is controlled at 380-440 mmHg, the first-stage evaporation heating temperature is 60-80℃, the second-stage evaporation heating temperature is 80-90℃, the ethanol solvent is removed and recycled, and finally concentrated to a solid content of 35%-60%; then it is spray-dried, the inlet air temperature of the spray dryer is 170-210℃, and the outlet air temperature is 85-100℃ to obtain camellia saponin.

10. The feeding method according to any one of claims 1-6, characterized in that, The basic feed comprises the following components in parts by weight: 2-5 parts fish meal, 2-5 parts fish solubles, 2-5 parts shrimp meal, 1-4 parts chicken meal, 2-5 parts blood meal, 3-7 parts 60% cottonseed protein, 15-30 parts 46% soybean meal, 2-8 parts peanut meal, 5-15 parts rapeseed meal and red cake, 2-8 parts distiller's grains, 20-30 parts wheat flour, 5-10 parts rice bran, 1-5 parts soybean lecithin oil, 2-5 parts bentonite, 2-5 parts calcium dihydrogen phosphate, and 0.01-0.05 parts phytosterols.

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