Cultivation method of sturgeon, sturgeon feed and preparation method thereof

Abstract

The present invention discloses a breeding method for sturgeon, a sturgeon feed and a preparation method thereof, belonging to the technical field of aquaculture. The sturgeon feed includes basic nutrients such as protein, fat, vitamins and minerals. In the feed, arachidonic acid accounts for 0.1% - 2% of the weight percentage of the feed. In addition, the present invention also provides a preparation method for the above sturgeon feed, including the following steps: S1. Mix fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, first flour and water, and granulate to obtain the first granules; S2. Mix the first granules, fish meal, soybean meal, chicken meal, squid visceral powder, sodium carboxymethylcellulose, calcium dihydrogen phosphate and second flour, and granulate and dry to obtain the second granules. In addition, the present invention also provides a breeding method for sturgeon. The feed provided by the present invention can develop the ovaries of 10-year-old Yangtze sturgeon at stage III to stage IV when fed.

Description

Technical Field

[0001] The present invention relates to the technical field of aquaculture, and particularly relates to a method for culturing sturgeon, a feed for sturgeon and a preparation method thereof. Background Art

[0002] Sturgeons are one of the earliest vertebrate groups to originate. Fossils of sturgeon fish were discovered as early as in the Jurassic period of the Mesozoic era 200 million years ago; sturgeon fish (Acipenseriformes) are characterized by large body size, long lifespan, and late sexual maturity. There are 27 species of sturgeons globally. Due to factors such as the construction of water conservancy projects, fishing, shipping, and pollution, most sturgeons are currently in different degrees of endangered states. There are 8 species of sturgeons in China, including the Huso dauricus and Acipenser schrenckii in the Heilongjiang River; the Acipenser baer, Acipenser ruthenus, and Acipenser nudiventris in waters such as the Irtysh River in Xinjiang; as well as the anadromous Chinese sturgeon (Acipenser sinensis Gray), the freshwater-resident Yangtze sturgeon (Acipenser dabryanus), and the Chinese paddlefish (Psephurus gladius) inhabiting the estuaries of the Yangtze River and large rivers. Unfortunately, the Chinese paddlefish, known as the "king of Chinese freshwaters," was declared functionally extinct in 2020. On July 21, 2022, the International Union for Conservation of Nature (IUCN) declared the Yangtze sturgeon "extinct in the wild." The Chinese sturgeon also faces the dilemma of continuous interruption of natural reproduction (from 2017 to 2023). If no active and effective artificial protection measures are taken, more and more sturgeon groups may disappear from our sight in the future.

[0003] The Yangtze sturgeon is a freshwater sedentary sturgeon in the middle and upper reaches of the Yangtze River in China. Its sexual maturity cycle is relatively long. The female reaches initial sexual maturity at 6 - 8 years old, and the male at 3 - 5 years old. After the 1980s, the scale of the natural population shrank sharply, and its natural breeding activities stopped after 2000. It was listed as a first-class protected wild animal in China in 1988, included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in 1997, upgraded to critically endangered (CR) species by the International Union for Conservation of Nature (IUCN) in 2010, and declared "extinct in the wild" by the IUCN in 2022. Under artificial conservation conditions, a group of Yangtze sturgeons has been conserved, and the artificial breeding technology of its second-generation offspring has been broken through, but the large-scale breeding of this species has not been achieved. During the breeding process, problems such as slow growth and development, long time to initial sexual maturity, asynchronous development of males and females, and low ratio of sexually mature female fish still exist. Recently, artificial breeding was carried out on the second-generation Yangtze sturgeons, and it was found that the induction success rate of female parents was only 33.33%. The absolute fecundity of cultured individuals was significantly lower than that of wild individuals, the egg diameter was also smaller than that of wild individuals, and there were three peak death periods during the seedling cultivation process. Thus, it can be seen that the key issue that still needs to be solved urgently is to tackle the regulation of gonadal development and the improvement of reproductive performance of the second-generation Yangtze sturgeon broodstock. Feeding with feed is beneficial to promoting the development of the Yangtze sturgeon, but currently, there is a lack of feed that can successfully develop the ovaries of Yangtze sturgeon broodstock to stage IV. Summary of the Invention

[0004] Recently, through the comparative analysis of the nutritional components of different tissues of sub-adult Yangtze sturgeons, it was found that fat and long-chain highly unsaturated fat play important roles in gonadal development. Studies on other cultured fish species have shown that dietary arachidonic acid can improve the synthesis of sex steroid hormones, gonadal development, and reproductive performance of broodstock. In view of the above review, the present invention mainly explores the effect of dietary arachidonic acid levels on the ovarian development of 10-year-old Yangtze sturgeons at stage III, and on the premise of meeting the basic nutritional requirements of Yangtze sturgeon broodstock at stage III, formulates feeds with different proportions of arachidonic acid to culture Yangtze sturgeon broodstock for 12 months, and examines the effects of arachidonic acid on the growth, fatty acid deposition, inflammatory factors, development ratio, and hormone synthesis of Yangtze sturgeon broodstock, so as to screen out an efficient feed formula for Yangtze sturgeon broodstock and produce a product for the cultivation of Yangtze sturgeon broodstock.

[0005] The purpose of the present invention is to overcome the above technical deficiencies, provide a cultivation method for sturgeons, a sturgeon feed, and its preparation method, and solve the technical problem in the prior art of how to successfully develop the ovaries of Yangtze sturgeon broodstock to stage IV by feeding with feed.

[0006] To achieve the above technical purpose, the technical solution of the present invention provides a sturgeon feed, which includes basic nutrients such as protein, fat, vitamins, and minerals. In the feed, arachidonic acid accounts for 0.1% - 2% of the weight percentage of the feed.

[0007] In any embodiment, by weight percentage, it includes: fish meal 30%-40%, soybean meal 10%-20%, chicken meal 10%-15%, squid viscera meal 5%-7%, fish oil 3%-4%, soybean oil 3%-4%, flour 20%-25%, choline 0.1%-0.4%, calcium dihydrogen phosphate 1%-1.5%, compound multivitamins 1%-2%, compound multiminerals 2%-3%, sodium carboxymethyl cellulose 2%-3% and arachidonic acid 0.1%-2%.

[0008] In any embodiment, it further includes probiotics 1%-1.5%.

[0009] In any embodiment, the probiotics are Bacillus subtilis.

[0010] In any embodiment, it further includes gelatin 1%-3%.

[0011] In addition, the present invention also provides a preparation method of the above sturgeon feed, including the following steps:

[0012] S1. Mix fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the first flour and water, and granulate to obtain the first granules;

[0013] S2. Mix the first granules, fish meal, soybean meal, chicken meal, squid viscera meal, sodium carboxymethyl cellulose, calcium dihydrogen phosphate and the second flour, and granulate and dry to obtain the second granules.

[0014] In any embodiment, in step S1, it further includes mixing probiotics and the third flour to obtain the third granules, and mixing the third granules, fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the second flour and water to obtain the first granules.

[0015] In any embodiment, in step S1, it further includes spraying gelatin on the surface of the first granules to obtain the first granules with gelatin-coated surface.

[0016] In any embodiment, in step S1, the mesh number of the first granules is 80-90 meshes.

[0017] In addition, the present invention also provides a cultivation method of sturgeon, including the following steps:

[0018] Feed the sturgeon feed or the sturgeon feed prepared by the above-mentioned preparation method twice a day. Use running water culture with a flow rate of 0.132 - 140 m³ / min. During the breeding period, the average water temperature is 18.15 - 18.5 °C, the water temperature variation range is 5.5 °C to 26.6 °C, the average dissolved oxygen is 7.55 - 8 mg / L, the dissolved oxygen variation range is 5.12 mg / L to 11.23 mg / L, the pH is 7.91 - 8.15, and the ammonia nitrogen is 0.08 - 0.30 mg / L;

[0019] When the water temperature drops below 10 °C, use natural lake water for low-temperature and flow rate stimulation. The water temperature variation range is 5.5 - 12.4 °C, and the average water temperature is 8.72 - 8.8 °C.

[0020] Compared with the prior art, the beneficial effects of the present invention include: The sturgeon feed proposed by the present invention includes basic nutrients such as protein, fat, vitamins, and minerals. In the feed, arachidonic acid accounts for 0.1% - 2% of the weight of the feed. The present invention explores the effect of adding arachidonic acid to the feed on the ovarian development of 10-year-old Yangtze sturgeon in the third stage. On the premise of meeting the basic nutritional requirements of the third-stage broodstock of Yangtze sturgeon, the broodstock of Yangtze sturgeon is cultured with the feed added with arachidonic acid for 12 months, and it is concluded that the feed proposed by the present invention can develop the ovarian of 10-year-old Yangtze sturgeon in the third stage to the fourth stage. Brief Description of the Drawings

[0021] Figure 1 It is the B-ultrasound photo after feeding the sturgeon broodstock with the feed proposed in Example 1 of the present invention for 1 year;

[0022] Figure 2 It is the statistical result chart of the blood sex hormones after feeding the sturgeon broodstock with the feeds proposed in Examples 1 - 2 and Comparative Example 1 of the present invention for 1 year. Detailed Embodiments

[0023] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a particular range. The ranges defined in this way can include or exclude the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, ranges of 60-110 and 80-120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviated representation of any real number combination between a and b, where both a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are fully listed herein, and "0-5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0024] Unless otherwise specified, the terms "comprising" and "including" mentioned in this application are open-ended and can also be closed-ended. For example, the said "comprising" and "including" can mean that other components not listed can also be included or contained, or can only include or contain the listed components.

[0025] Unless otherwise specified, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) while B is true (or exists); or both A and B are true (or exist).

[0026] This specific embodiment provides a sturgeon feed, comprising basic nutrients such as protein, fat, vitamins, and minerals, and is characterized in that, in the feed, arachidonic acid accounts for 0.1%-2% of the weight percentage of the feed.

[0027] In some embodiments, by weight percentage, it includes: fish meal 30%-40%, soybean meal 10%-20%, chicken meal 10%-15%, squid viscera meal 5%-7%, fish oil 3%-4%, soybean oil 3%-4%, flour 20%-25%, choline 0.1%-0.4%, calcium dihydrogen phosphate 1%-1.5%, compound multivitamins 1%-2%, compound multiminerals 2%-3%, sodium carboxymethyl cellulose 2%-3% and arachidonic acid 0.1%-2%. With the cooperation of each component, on the premise of meeting the basic nutritional requirements of the third-stage broodstock of Yangtze sturgeon

[0028] In some embodiments, it further includes probiotics 1%-1.5%.

[0029] In some embodiments, the probiotics are Bacillus subtilis. After Bacillus subtilis enters the intestine of sturgeon, it can promote the degradation of nutrients in the feed, making the sturgeon absorb and utilize the feed more fully.

[0030] In some embodiments, it further includes gelatin 1%-3%.

[0031] In addition, the present invention also provides a preparation method of the above-mentioned sturgeon feed, including the following steps:

[0032] S1. Mix fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the first flour and water, and granulate to obtain the first granule;

[0033] S2. Mix the first granule, fish meal, soybean meal, chicken meal, squid viscera meal, sodium carboxymethyl cellulose, calcium dihydrogen phosphate and the second flour, and granulate and dry to obtain the second granule.

[0034] In some embodiments, in step S1, it further includes mixing the probiotics and the third flour to obtain the third granule, and mixing the third granule, fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the second flour and water to obtain the first granule. The probiotics are protected inside the layer, which helps to extend the time of its effectiveness, can be continuously released, and helps the sturgeon to digest and absorb the feed.

[0035] In some embodiments, in step S1, it further includes spraying gelatin on the surface of the first granule to obtain the first granule with gelatin-coated surface. After the first granule is coated with gelatin, it helps the feed to first digest the indigestible part outside the first granule after entering the intestine, and at the same time, the components inside the first granule are continuously and slowly released, which can not only ensure the growth needs of the sturgeon, but also avoid the components inside the first granule being discharged out of the fish body without being fully absorbed, and more importantly, avoid the loss caused by the direct dispersion of components such as arachidonic acid into the water after the feed enters the water.

[0036] In some embodiments, the mesh number of the first particles is 80 - 90 mesh.

[0037] In addition, this specific embodiment also provides a method for culturing sturgeon, comprising the following steps:

[0038] Feed the above-mentioned sturgeon feed or the sturgeon feed prepared by the above-mentioned preparation method twice a day. Use flowing water for cultivation, with a flow rate of 0.132 - 140 m³ / min. The average water temperature during the cultivation period is 18.15 - 18.5 °C, the range of water temperature variation is 5.5 °C to 26.6 °C, the average dissolved oxygen is 7.55 - 8 mg / L, the range of dissolved oxygen variation is 5.12 mg / L to 11.23 mg / L, the pH is 7.91 - 8.15, and the ammonia nitrogen is 0.08 - 0.30 mg / L;

[0039] When the water temperature drops below 10 °C, use natural lake water for low-temperature and flow rate stimulation. The range of water temperature variation is 5.5 - 12.4 °C, and the average water temperature is 8.72 - 8.8 °C.

[0040] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] In the present invention, references to "some embodiments", "this embodiment", and examples, etc., describe subsets of all possible embodiments. However, it can be understood that "some embodiments" can be the same subsets or different subsets of all possible embodiments and can be combined with each other without conflict.

[0042] If similar descriptions such as "first / second" appear in the application documents, the following explanation is added. In the following description, the terms "first / second / third" only distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first / second / third" can be interchanged in a specific order or sequence when allowed, so that the embodiments described here can be implemented in an order other than the one illustrated or described here.

[0043] In this embodiment, the term "and / or" only describes the association relationship of associated objects and represents three possible relationships. For example, object A and / or object B can represent: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0044] The embodiments of the present application will be described below. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as a limitation of the present application. For those techniques or conditions not specified in the embodiments, they shall be carried out according to the techniques or conditions described in the literature in this field or according to the product specifications. For reagents or instruments whose manufacturers are not specified, they are all conventional products that can be obtained through commercial purchase.

[0045] It should be noted that in the following embodiments or comparative examples, each kilogram of feed contains a vitamin premix: VB1 50 mg, VB2 200 mg, VB6 50 mg, VB 12 20 mg, folic acid 15 mg, V c 325 mg, pantothenic acid 400 mg, inositol 1500 mg, D-biotin (2%) 5 mg, niacin 750 mg, V A 2.5 mg, V E (50%) 250 mg, VD3 2 mg, V K 20 mg.

[0046] Each kilogram of feed contains a mineral salt premix: Ca(H2PO4)2 1800 mg, KH2PO4 1350 mg, NaCl 500 mg, MgSO4·7H2O 750 mg, NaH2PO4·2H2O 650 mg, KI 1.5 mg, CoSO4·6H2O 2.5 mg, CuSO4·5H2O 15 mg, ZnSO4·7H2O 350 mg, FeSO4·7H2O 1250 mg, MnSO4·4H2O 80 mg, Na2SeO3 6.00 mg.

[0047] The gelatin solution in the following embodiments or comparative examples is a gelatin solution prepared by dissolving gelatin in deionized water. The mesh number of the first particles in the following embodiments is 80-90 mesh.

[0048] Example 1

[0049] This example provides a sturgeon feed, which includes, by weight percentage: fish meal 35%, soybean meal 15%, chicken meal 10%, squid viscera meal 5%, fish oil 3.5%, soybean oil 3.5%, flour 20.6%, choline 0.2%, calcium dihydrogen phosphate 1.2%, compound multivitamins 1%, compound multiminerals 2%, sodium carboxymethylcellulose 2%, and arachidonic acid 1%.

[0050] This example also provides a preparation method of the above sturgeon feed, which includes the following steps:

[0051] Mix fish meal, soybean meal, chicken meal, squid visceral meal, flour, compound multivitamins, compound multiminerals, choline, calcium dihydrogen phosphate, and sodium carboxymethyl cellulose in a mixer. Then, add fish oil, soybean oil, arachidonic acid, and 15% of the total mass of each component of water to form a wet-based mixture. Place the wet-based mixture in a feed granulator and extrude it to form cylindrical long-strip granules. Dry it in a cool and dry place and then store it in a -20°C refrigerator for later use.

[0052] Example 2

[0053] This example presents a sturgeon feed, which, calculated by weight percentage, includes: 35% fish meal, 15% soybean meal, 10% chicken meal, 5% squid visceral meal, 3% fish oil, 3% soybean oil, 20.6% flour, 0.2% choline, 1.2% calcium dihydrogen phosphate, 1% compound multivitamins, 2% compound multiminerals, 2% sodium carboxymethyl cellulose, and 2% arachidonic acid.

[0054] The preparation method of the sturgeon feed in this example is the same as that in Example 1.

[0055] Example 3

[0056] The formula of the sturgeon feed proposed in this example is the same as that in Example 1.

[0057] This example also presents a preparation method for this sturgeon feed, including the following steps:

[0058] S1. According to the above ratio, mix fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, first flour, and first water, and granulate to obtain the first granules; the amount of the first water used is 8% of the mass of the first flour.

[0059] S2. Mix the first granules, fish meal, soybean meal, chicken meal, squid visceral meal, sodium carboxymethyl cellulose, calcium dihydrogen phosphate, second flour, and second water, and granulate and dry to obtain the second granules; the amount of the second water used is 10% of the mass of the second flour.

[0060] The mass ratio of the first flour to the second flour is 1:4, and the total amount of the first flour and the second flour used is the amount of flour in the sturgeon feed formula.

[0061] Example 4

[0062] The formula of the sturgeon feed proposed in this example is the same as that in Example 2.

[0063] This example also presents a preparation method for the above sturgeon feed, including the following steps:

[0064] S1. According to the above ratio, mix fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the first flour and the first water, and granulate to obtain the first granules; the amount of the first water used is 8% of the mass of the first flour;

[0065] S2. Mix the first granules, fish meal, soybean meal, chicken meal, squid visceral powder, sodium carboxymethyl cellulose, calcium dihydrogen phosphate, the second flour and the second water, and granulate and dry to obtain the second granules; the amount of the second water used is 10% of the mass of the second flour;

[0066] The mass ratio of the first flour to the second flour is 1:4, and the total amount of the first flour and the second flour used is the amount of flour in the sturgeon feed formula.

[0067] Example 5

[0068] The difference between the sturgeon feed of this example and that of Example 3 is only that it further includes 1.5% of Bacillus subtilis.

[0069] This example also provides a preparation method of the above sturgeon feed, including the following steps:

[0070] S1. According to the above ratio, mix Bacillus subtilis, the third flour and the third water, and granulate to obtain the third granules, and then mix the third granules, fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the first flour and the first water, and granulate to obtain the first granules; the amount of the third water used is 5% of the mass of the third flour, and the amount of the first water used is 8% of the mass of the first flour;

[0071] S2. Mix the first granules, fish meal, soybean meal, chicken meal, squid visceral powder, sodium carboxymethyl cellulose, calcium dihydrogen phosphate, the second flour and the second water, and granulate and dry to obtain the second granules; the amount of the second water used is 10% of the mass of the second flour;

[0072] The mass ratio of the third flour, the first flour and the second flour is 0.2:1:3.8; the total amount of the third flour, the first flour and the second flour used is the amount of flour in the sturgeon feed formula.

[0073] Example 6

[0074] The difference between the sturgeon feed of this example and that of Example 3 is only that it further includes 1% of Bacillus subtilis.

[0075] This example also provides a preparation method of the above sturgeon feed, including the following steps:

[0076] S1. According to the above ratio, mix Bacillus subtilis, the third flour, and the third water, and granulate to obtain the third granule. Mix the third granule, fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the first flour, and the first water, and granulate to obtain the first granule; the dosage of the third water is 5% of the mass of the third flour, and the dosage of the first water is 8% of the dosage of the first flour.

[0077] S2. Mix the first granule, fish meal, soybean meal, chicken meal, squid visceral powder, sodium carboxymethyl cellulose, calcium dihydrogen phosphate, the second flour, and the second water, and granulate and dry to obtain the second granule; the dosage of the second water is 10% of the dosage of the second flour.

[0078] The mass ratio of the third flour, the first flour, and the second flour is 0.2:1:3.8; the total dosage of the third flour, the first flour, and the second flour is the dosage of the flour in the sturgeon feed formula.

[0079] Example 7

[0080] The difference between the sturgeon feed of this example and that of Example 3 is only that it further includes 2% of gelatin.

[0081] This example also provides a preparation method of the above sturgeon feed, including the following steps:

[0082] S1. According to the above ratio, mix fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the first flour, and the first water, and granulate to obtain the first granule; the dosage of the first water is 8% of the mass of the first flour; after spraying a gelatin solution on the surface of the first granule, dry it to obtain the first granule with gelatin coated on the surface.

[0083] S2. Mix the first granule with gelatin coated on the surface, fish meal, soybean meal, chicken meal, squid visceral powder, sodium carboxymethyl cellulose, calcium dihydrogen phosphate, the second flour, and the second water, granulate, and then dry to obtain the second granule; the dosage of the second water is 10% of the mass of the second flour.

[0084] The mass ratio of the first flour and the second flour is 1:4, and the total dosage of the first flour and the second flour is the dosage of the flour in the sturgeon feed formula.

[0085] Example 8

[0086] The difference between the sturgeon feed of this example and that of Example 7 is only that it further includes 1.5% of Bacillus subtilis.

[0087] This example also provides a preparation method of the above sturgeon feed, including the following steps:

[0088] S1. According to the above ratio, mix Bacillus subtilis, the third flour, and the third water to obtain the third granule. Mix the third granule, fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the first flour, and the first water, and granulate to obtain the first granule. The amount of the third water is 5% of the mass of the third flour, and the amount of the first water is 8% of the amount of the first flour. Spray a gelatin solution on the surface of the first granule and then dry to obtain the first granule with a gelatin coating on the surface.

[0089] S2. Mix the first granule with a gelatin coating on the surface, fish meal, soybean meal, chicken meal, squid visceral powder, sodium carboxymethylcellulose, calcium dihydrogen phosphate, the second flour, and the second water, granulate, and then dry to obtain the second granule. The amount of the second water is 10% of the mass of the second flour.

[0090] The mass ratio of the third flour, the first flour, and the second flour is 0.2:1:3.8. The total amount of the third flour, the first flour, and the second flour is the amount of flour in the sturgeon feed formula.

[0091] Comparative Example 1

[0092] The difference between this comparative example and Example 1 is that it does not contain arachidonic acid. This example presents a sturgeon feed, which, calculated by weight percentage, includes: 35% fish meal, 15% soybean meal, 10% chicken meal, 5% squid visceral powder, 4% fish oil, 4% soybean oil, 20.6% flour, 0.2% choline, 1.2% calcium dihydrogen phosphate, 1% compound multivitamins, 2% compound multiminerals, and 2% sodium carboxymethylcellulose.

[0093] This comparative example also presents a preparation method for the above sturgeon feed, including the following steps:

[0094] Mix fish meal, soybean meal, chicken meal, squid visceral powder, flour, compound multivitamins, compound multiminerals, choline, calcium dihydrogen phosphate, and sodium carboxymethylcellulose in a mixer, then add fish oil, soybean oil, and water accounting for 15% of the total mass of each component to form a wet-based mixture. Place the wet-based mixture in a feed granulator and extrude it into cylindrical long-strip granules. Dry it in a cool and dry place and then store it in a -20°C refrigerator for later use.

[0095] Comparative Example 2

[0096] The difference between this comparative example and Example 8 is only in the preparation method of the sturgeon feed. Directly mix all components to obtain the second granule, including the following steps:

[0097] S1. According to the component ratios in Example 8, mix all components and water, granulate, and then dry to obtain the second granule.

[0098] Farming experiment:

[0099] Before the experiment started, 27 healthy Yangtze sturgeons with consistent specifications and in the III stage of ovarian development were selected by B-ultrasound and randomly divided into 3 groups. Each group was fed the feed of Example 1, Example 2, and Comparative Example 1 respectively. 9 fish in each group were cultured in an oval cement pond with a volume of 24.5m 2 , with a water depth of 1.0m and an effective culture volume of 24.5m 3 . The culture biomass was 4.77m / kg, and the culture period was 12 months. The feed was fed twice a day (the feeding times were 8:00 and 20:00 respectively), and the daily feeding rate was 0.6%. The culture water was deep underground well water, which flowed directly into the culture pond after aeration and sand filtration. Flow-through culture was adopted, with a flow rate of 0.132m / min. The sewage was discharged twice a day, 30 minutes before feeding the feed, and the drainage volume accounted for about 1 / 5 of the total volume. The water temperature and dissolved oxygen were measured once a day, and the pH and ammonia nitrogen were measured once a week. During the culture period, the average water temperature was 18.15°C, the water temperature variation range was 5.5°C - 26.6°C, the average dissolved oxygen was 7.55mg / L, the dissolved oxygen variation range was 5.12mg / L - 11.23mg / L, the pH was 7.91 - 8.15, and the ammonia nitrogen was 0.08 - 0.30mg / L.

[0100] Low temperature and flow rate creation measures: Based on the developmental physiological characteristics of the Yangtze sturgeon, it requires a certain period of low temperature and flow rate stimulation. When the natural water temperature drops below 10°C, natural lake water is used for low temperature and flow rate stimulation to promote its development. In this study, the low temperature response time was 30 days, the water temperature variation range was 5.5 - 12.4°C, and the average water temperature was 8.72°C.

[0101] The creation of the flow rate was mainly achieved by pumping water into the culture pond with a submersible pump and then converting it into a high-pressure water flow with a large impact force through the water outlet, so as to form a large water flow on the surface layer of the pond, making a certain amount of micro-flow water in the whole culture pond. In this study, the micro-flow water stimulation lasted for 30 days, which was consistent with the duration of low temperature.

[0102] Research results

[0103] (1) Effects of arachidonic acid (ARA) on the growth and health status of female Yangtze sturgeon broodstock in the III stage

[0104] Sturgeon with an initial average body weight of 13.36 ± 0.59 kg were evenly divided into 3 treatment groups, with 9 test fish in each treatment group, for a total of 27 female sturgeon broodstock. The stage III sturgeon broodstock were cultured with arachidonic acid feed for 1 year, and growth performance data such as ① body length, weight gain rate, survival rate, and feed coefficient of the test broodstock with different arachidonic acid contents in the feed were obtained, and the effect of ARA feed on the growth effect of sturgeon was evaluated. The results showed that the weight gain rate of the test fish in the 1% ARA group (Example 1) was the highest, significantly higher than that in the 0% ARA group (p < 0.05) (Comparative Example 1), and there was no significant difference from the 2% ARA group (Example 2) (p > 0.05). There was a tendency for the weight gain rate to decrease with the increase in the ARA content of the feed, and at the same time, the feed coefficient of the 1% ARA group was the lowest. There was no significant difference in the survival rate and final body weight among the groups (p > 0.05). The specific results are shown in Table 1.

[0105] ② The immune indexes such as TNF-α, IL-1β, IL-6, IL-8, IL-10, and TGF-β1 in serum and mucus were measured using an inflammatory factor kit, and the effect of ARA feed on the health and immune function of sturgeon was evaluated. The results showed that there was no significant difference in blood IL-1β and IL-10 among the groups (p > 0.05). The contents of blood TNF-α and TGF-β1 were the highest in the 1% ARA group, significantly higher than those in the 2% ARA group; the IL-6 content in the 2% ARA group was significantly higher than that in the 0% and 1% ARA groups (p < 0.05); the IL-8 in the 0% ARA group was significantly higher than that in the 1% ARA group (p < 0.05), and there was no significant difference from the 2% ARA group (p > 0.05). Mucus TNF-α and IL-1β were not affected by the ARA content of the feed; the contents of IL-10 and TGF-β1 were the highest in the 1% ARA group, significantly higher than those in the 0% ARA group, and the IL-10 content in the 1% ARA group was significantly higher than that in the 0% ARA group, and the TGF-β1 content in the 2% ARA group was significantly higher than that in the 0% and 1% ARA groups; IL-6 showed an upward trend with the increase in the ARA content of the feed, while IL-8 showed the opposite trend. The IL-6 content in the 0% ARA group was significantly lower than that in the 2% ARA group, and the IL-8 content in the 0% ARA group was significantly higher than that in the 2% ARA group. The specific results are shown in Table 2.

[0106] Table 1: Effects of arachidonic acid on the growth performance and feed utilization of stage III female Yangtze sturgeon broodstock

[0107]

[0108] Note: Different superscript letters in the same row of data indicate significant differences (p < 0.05), the same or no letters indicate no significant differences (p > 0.05), and the number of replicates is n = 9.

[0109] Table 2: Effects of Arachidonic Acid on Serum and Mucus Inflammatory Factors of Female Yangtze Sturgeon Broodstock at Stage III (pg / ml)

[0110]

[0111] Note: Different lowercase letters in the same row indicate significant differences (p < 0.05), while the same or no letters indicate no significant differences (p

[0112] > 0.05). The number of replicates for blood is n = 3, and the number of replicates for mucus is n = 4.

[0113] Effects of Arachidonic Acid on Hormone Synthesis and Oocyte Development of Female Yangtze Sturgeon Broodstock at Stage III

[0114] After feeding sturgeon broodstock with arachidonic acid-containing feed for 1 year, ovarian development was monitored by B-ultrasound. Meanwhile, the blood of the experimental fish was collected to measure serum sex hormones. Combining with Table 3, the B-ultrasound monitoring results showed that the proportion of broodstock in the 1% ARA group with ovarian development reaching stage IV was the highest, followed by the 2% ARA group, and the 0% ARA group was the lowest. The B-ultrasound monitoring results of the development of some broodstock are shown in Figure 1 . It should be noted that in Example 2, the genders of 2 fish could not be distinguished, so only the proportion of 7 fish developing to stage IV broodstock could be calculated. Among the 7 fish, 6 fish developed to stage IV broodstock.

[0115] Table 3: Effects of Arachidonic Acid on the Development Proportion of Female Yangtze Sturgeon Broodstock at Stage III

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[0117] Combining Figure 2 , the blood sex hormone results showed that the estradiol content in the 2% ARA group was the highest, and the follicle-stimulating hormone content was the lowest; the testosterone content was consistent among the 3 groups; the luteinizing hormone content in the 1% ARA group was the highest.

[0118] On the basis of the above breeding experiment, we further optimized the plan. Sturgeon were cultured with the feed prepared in Examples 3-8 and Comparative Example 2. The breeding experiment method was the same as above, but the number of sturgeon in each group was increased to 15. After 1 year of breeding, the weight change and oocyte development were detected, and the results are shown in Tables 4, 5 and 6.

[0119] Table 4: Effects of Examples 3-6 on the Growth Performance of Female Yangtze Sturgeon Broodstock at Stage III

[0120]

[0121] Table 5: Effects of Examples 7-8 and Comparative Example 2 on the Growth Performance of Female Yangtze Sturgeon Broodstock at Stage III

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[0123] Table 6: Effects of Examples 3-8 and Comparative Example 2 on the development ratio of female Yangtze sturgeon broodstock at stage III

[0124] Percentage of broodstock developed to stage IV Example 3 93.33 Example 4 86.67 Example 5 93.33 Example 6 93.33 Example 7 100 Example 8 100 Comparative Example 2 86.67

[0125] Combined with Tables 4-6, it can be seen that the feeds prepared in Examples 3-8 can significantly increase the body weight of sturgeons and the ratio of development to broodstock at stage IV, which is higher than that in Examples 1-2; in particular, the feed prepared in Example 8 is the most obvious in increasing the body weight of sturgeons, and can develop 100% of female sturgeons at stage III to broodstock at stage IV.

[0126] The specific implementation manners of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A sturgeon feed, characterized in that, Calculated by weight percentage, it includes: fish meal 30%-40%, soybean meal 10%-20%, chicken meal 10%-15%, squid viscera powder 5%-7%, fish oil 3%-4%, soybean oil 3%-4%, flour 20%-25%, choline 0.1%-0.4%, calcium dihydrogen phosphate 1%-1.5%, compound multivitamins 1%-2%, compound multiminerals 2%-3%, sodium carboxymethyl cellulose 2%-3% and arachidonic acid 0.1%-2%. It also includes 1%-1.5% of probiotics, and the probiotics are Bacillus subtilis. It also includes 1%-3% of gelatin; The sturgeon feed is prepared by the following steps: S1. Mix and granulate fish oil, soybean oil, choline, arachidonic acid, compound multivitamins, compound multiminerals, the first flour and water to obtain the first granules; spray a gelatin solution on the surface of the first granules to obtain the first granules with a gelatin coating on the surface; S2. Mix the first granules with a gelatin coating on the surface, fish meal, soybean meal, chicken meal, squid viscera powder, sodium carboxymethyl cellulose, calcium dihydrogen phosphate and the second flour, granulate and dry to obtain the second granules; in the mixing and granulation of step S1, it also includes adding the third granules obtained by mixing probiotics, water and the third flour.

2. A method for culturing sturgeon, characterized in that, It includes the following steps: Feed the sturgeon feed described in claim 1 twice a day, adopt flowing water culture, the flow rate is 0.132 m³ / min, the average water temperature during the culture period is 18.15-18.5 °C, the water temperature variation range is 5.5 °C to 26.6 °C, the average dissolved oxygen is 7.55-8 mg / L, the dissolved oxygen variation range is 5.12 mg / L to 11.23 mg / L, the pH is 7.91-8.15, and the ammonia nitrogen is 0.08-0.30 mg / L.

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