Aquatic group breeding and seedling raising method based on water temperature-hormone cooperative regulation and application

Abstract

The invention belongs to the technical field of aquaculture, and particularly relates to an aquatic population breeding and seedling raising method based on water temperature-hormone cooperative regulation and control and application of the aquatic population breeding and seedling raising method based on water temperature-hormone cooperative regulation and control. The growth regulator is used for enhancing the reproduction promoting effect of luteinizing hormone releasing hormone or analogues thereof; propagation promotion refers to promotion of oocyte growth, promotion of yolk accumulation, shortening of ovary development cycle and improvement of oviposition rate. The invention discovers and verifies the fish breeding promoting effect of the butyric acid and the sodium salt thereof for the first time, wherein the butyric acid and the sodium salt thereof can enhance luteinizing hormone release hormone.

Description

Technical Field

[0001] The present invention belongs to the technical field of aquaculture, and in particular relates to a method for breeding and raising aquatic populations based on coordinated regulation of water temperature and hormones and its application. Background Art

[0002] In aquaculture, water temperature and hormone regulation are core technologies for inducing synchronized reproduction and seedling rearing in aquatic populations. The core of water temperature regulation is to mimic the seasonal signals of natural reproduction. The reproductive activities of most aquatic animals are closely linked to changes in water temperature. For example, in carp species, when water temperatures rise to 15°C to 20°C in spring, the hypothalamus secretes luteinizing hormone-releasing hormone, triggering the pituitary gland to secrete luteinizing hormone, ultimately inducing oocyte maturation and spermatogenesis. In artificial aquaculture, temperature gradients or constant temperature control can be used to break animals' hibernation and synchronize gonadal development, enabling mass seedling rearing. This regulation method has the advantage of aligning closely with natural physiological patterns and minimizing drastic disruption to the organism's internal environment.

[0003] Hormonal regulation directly intervenes in the reproductive axis system through exogenous substances. Commonly used hormones include luteinizing hormone-releasing hormone analogs (LHRHa) and human chorionic gonadotropin (HCG). Their mechanism of action bypasses the constraints of environmental signals such as water temperature and directly stimulates the pituitary gland to secrete gonadotropins, accelerating gonadal maturation. For example, in shrimp seedlings, injection of LHRHa can shorten the ovarian development cycle of female shrimp from the natural 30 days to 15 days, and increase the spawning rate to over 80%.

[0004] However, both water temperature and hormone regulation have significant drawbacks when used alone. Temperature regulation alone is ineffective in promoting reproduction, while hormone regulation alone carries the risk of residual effects. Excessive hormone use can accumulate in aquatic broodstock, potentially posing a threat to human health through the food chain.

[0005] Therefore, how to balance water temperature control and hormone control conditions and reduce the defects of these two control methods is a problem that needs to be solved at present. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a method and application of aquatic population reproduction and seedling raising based on coordinated regulation of water temperature and hormones.

[0007] The purpose of the present invention is to provide an application of a growth regulator in aquatic population reproduction and seedling cultivation based on water temperature-hormone coordinated regulation, wherein the growth regulator is butyric acid or sodium butyrate; the growth regulator is used to enhance the effect of luteinizing hormone-releasing hormone or its analogues in promoting aquatic reproduction; the promoting aquatic reproduction refers to promoting the growth of aquatic oocysts, promoting yolk accumulation, shortening the ovarian development cycle and improving the spawning rate.

[0008] The present invention also provides a method for aquatic population reproduction and seedling raising based on water temperature-hormone coordinated regulation, comprising: Select fish bred in spring as broodstock; Configure the breeding environment to provide basic nutritional conditions for the reproduction of broodstock; Water temperature and hormone coordinated regulation: At the beginning of spring, broodstock are released into the breeding environment to raise the water temperature in the pond at a rate of 0.5°C to 2.5°C per day. Starting from the second day of the temperature increase, growth regulators are added. When the water temperature in the pond is between 8°C and 30°C, the temperature is maintained constant. During the process of maintaining the constant temperature, exogenous hormones are injected. Basic feed is added during the breeding period until spawning and reproduction are completed; The exogenous hormone is luteinizing hormone-releasing hormone, and the injection dose of the exogenous hormone shall not exceed 4 μg / kg based on the fresh weight of the broodstock at the time of injection; The growth regulator is butyric acid or sodium butyrate, and the daily dosage is 2 μg / kg to 3 μg / kg, based on the average fresh weight of the broodstock at the time of stocking. The average fresh weight of the broodstock is calculated by randomly selecting 10 fish, weighing them, and taking the average.

[0009] Preferably, the temperature of the broodstock for warm water breeding is maintained at a constant value of 15°C to 20°C; For broodstock bred in cold water, the temperature should be maintained constant at 8℃~14℃.

[0010] Preferably, the broodstock is bream.

[0011] Preferably, the injection dose of the luteinizing hormone-releasing hormone is 2 μg / kg.

[0012] Preferably, the exogenous hormone is injected once.

[0013] Preferably, the growth regulator is administered continuously for 3 to 5 days.

[0014] Preferably, the growth regulator is mixed into the basal feed.

[0015] Preferably, the basal feed is made by mixing the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, CMC (sodium carboxymethyl cellulose) 2.00%, cellulose 0.50%.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention, for the first time, discovers and verifies that a growth regulator can enhance the reproductive-promoting effect of luteinizing hormone-releasing hormone in fish. The growth regulator is butyric acid or sodium butyrate; the reproductive enhancement refers to promoting oocyte growth, yolk accumulation, shortening the ovarian development cycle, and increasing spawning rates, providing related new applications.

[0017] The aquatic group breeding and seedling raising method of the present invention affects the hypothalamic-pituitary-gonadal axis signal of the parent fish by raising the water temperature, stimulating the pituitary gland to synthesize and secrete gonadotropins (GtH), including follicle-stimulating hormone (FSH) and luteinizing hormone (LH). By injecting exogenous hormones, the effects of the aquatic animal's own hormones can be simulated or enhanced, accelerating gonadal development and ovulation. In order to reduce the dosage of exogenous hormones, the present invention administers a growth regulator before injecting the exogenous hormones. The growth regulator comprises butyric acid or sodium butyrate. Butyric acid and sodium butyrate are used to strengthen the function of the exogenous hormones, promote the secretion of GtH, promote the growth of oocytes and the accumulation of yolk, accelerate gonadal development and ovulation, and ultimately shorten the ovarian development cycle and increase the spawning rate. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments.

[0019] In the description of the present invention, unless otherwise specified, all reagents used are commercially available and all methods used are conventional techniques in the art.

[0020] The inventive concept of the present invention is as follows: To reduce the impact of water temperature fluctuations on aquatic animal growth, minimize hormone usage, reduce hormone accumulation and residue in aquatic broodstock, and improve their safety, the present invention provides a growth regulator for use in aquatic population breeding and seedling rearing based on water temperature and hormone synergistic regulation. The growth regulator is butyric acid or sodium butyrate. The reproductive enhancement mechanism promotes oocyte growth, yolk accumulation, shortens the ovarian development cycle, and increases spawning rate. This invention is the first to discover and verify that butyric acid and its sodium salt (sodium butyrate) can enhance the reproductive-promoting effects of luteinizing hormone-releasing hormone in fish.

[0021] Based on the above findings, the present invention has conducted further research and provided a method for aquatic population reproduction and seedling raising based on water temperature-hormone coordinated regulation, comprising the following steps: (1) Selection of aquatic broodstock Broodstock should be selected from individuals that are robust, disease-free, have well-developed gonads, and possess excellent genetic traits. Because different species have significant differences in morphology and growth habits, the method of the present invention is suitable for spring-breeding fish, such as bream (also known as amblycephalic bream), crucian carp, common carp, grass carp, or black carp.

[0022] (2) Configure the breeding environment to meet the basic nutritional conditions of aquatic broodstock.

[0023] (3) Water temperature-hormone coordinated regulation At the beginning of spring, broodstock are released into the pond to raise the water temperature in the pond. The daily temperature increase rate is 0.5℃~2.5℃. Starting from the second day of the temperature increase, growth regulators are added. At this time, the gonads of the broodstock gradually develop, making preliminary preparations for reproduction. When the water temperature in the pond is 8℃~30℃, the temperature is maintained constant. At this time, the gonads of the broodstock mature rapidly and quickly reach the breeding standards.

[0024] It should be noted that different types of broodstock have different requirements for constant water temperature. Some fish are suitable for warm water breeding, such as carp, so the temperature should be maintained at a constant value of 15℃~30℃. Some fish are suitable for cold water breeding, such as salmon, so the temperature should be maintained at a constant value of 8℃~14℃.

[0025] In the process of maintaining a constant temperature, exogenous hormones are injected. After the injection of exogenous hormones, growth regulators are added. Basic feed is added during the breeding period until spawning and reproduction are completed.

[0026] The mechanism of this invention is as follows: By increasing water temperature, it influences the hypothalamic-pituitary-gonadal axis signaling in broodstock, stimulating neurosecretory cells in the broodstock's hypothalamus and prompting the secretion of luteinizing hormone-releasing hormone (GnRH). GnRH is transported to the pituitary gland via the bloodstream, where it binds to GnRH receptors there, stimulating the pituitary gland to synthesize and secrete gonadotropins (GtH), including follicle-stimulating hormone (FSH) and luteinizing hormone (LH). FSH and LH further act on the gonads, promoting gonadal cell proliferation and differentiation, inducing oocyte growth, maturation, and spermatogenesis. Injecting exogenous hormones can mimic or enhance the effects of aquatic animals' own hormones, accelerating gonadal development and ovulation. The exogenous hormones used in this invention are luteinizing hormone-releasing hormone or its analogue, LRH-A2 (ovulation hormone 2). After exogenous hormones stimulate the pituitary gland to secrete GtH, the FSH in GtH promotes oocyte growth and yolk accumulation, leading to oocyte maturation. At the same time, LH plays a key role in the late stages of oocyte maturation, prompting theca cells to synthesize and secrete steroid hormones. These steroid hormones further induce the oocyte to complete meiosis and ovulate. Furthermore, to reduce the dosage of exogenous hormones, the present invention administers growth regulators, consisting of butyric acid or sodium butyrate, prior to the injection of exogenous hormones. Butyric acid and sodium butyrate are used to reinforce the function of exogenous hormones, promoting GtH secretion, oocyte growth and yolk accumulation, accelerating gonadal development and ovulation, ultimately shortening the ovarian development cycle and increasing egg production.

[0027] The innovations of the present invention are described below with reference to specific examples and data. It should be noted that, except for the differences noted in the following examples, other cultivation methods and the amount of basal feed administered were all carried out in accordance with conventional methods in the art, and the same measures were employed, such as: a basal diet of 2% of the fresh body weight of the broodstock was administered twice daily; and oxygenation was performed daily to maintain a dissolved oxygen content of 5 mg / L in the water.

[0028] In conjunction with the specific embodiments below, the raw materials of the basic feed are purchased from the following sources: Fishmeal: Pakistani fishmeal, Tianjin Haiwei International Trade Co., Ltd. Soybean meal: Soybean meal, Lvshui (Jinan) Chemical Co., Ltd. Rapeseed meal: Shandong Huachen Biotechnology Co., Ltd., product name rapeseed meal. Cottonseed meal: Lingshou County Xinde Agricultural Products Co., Ltd. Fish oil: Shandong Baiqianhui Biotechnology Co., Ltd. Soybean oil: Jinan Xinyimin Chemical Technology Co., Ltd., product name crude soybean oil. Corn starch and wheat flour were purchased at local farmers' markets. Corn bran: Yuncheng Jinhui Biological Feed Co., Ltd. Choline: Hebei Chuangzhiyuan Biotechnology Co., Ltd., product name choline chloride. Aquaculture vitamin premix: Shandong Qilu Chemical Technology Co., Ltd., product name electrolytic multivitamin. Sodium carboxymethyl cellulose: Xi'an Lavia Biotechnology Co., Ltd. Cellulose: Hebei Yufei Chemical Co., Ltd., product name carboxymethyl cellulose.

[0029] In order to explore the effects of different growth regulator dosages on the reproduction of aquatic populations, the present invention provides Examples 1 to 4 and Control Groups 1 to 5.

[0030] Example 1 A method for aquatic population reproduction and seedling raising based on water temperature-hormone coordinated regulation comprises the following steps: (1) Selection of aquatic broodstock Three-year-old (3-year-old) amblycephalic bream individuals with healthy body shape, no disease, well-developed gonads and excellent genetic traits were selected as broodstock.

[0031] (2) Configure the breeding environment After the end of winter, the female bighead carp enters the ovarian development stage III at the beginning of spring. Water is added to the pond to increase oxygen, and the dissolved oxygen content in the water is maintained at 5 mg / L. Basic feed is added to meet the basic nutritional conditions of aquatic broodstock.

[0032] The basic feed is a mixture of the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, sodium carboxymethyl cellulose 2.00%, cellulose 0.50%.

[0033] (3) Water temperature-hormone coordinated regulation After configuring the breeding environment, broodstock are put into the pond and the water temperature in the pond is raised at a daily rate of 0.5°C. Starting from the second day of warming, the growth regulator butyric acid is added. The growth regulator is added for three consecutive days. During the warming period, the gonads of the broodstock gradually develop, making preliminary preparations for reproduction. When the water temperature in the pond is 24°C, the temperature is maintained constant. At this time, the gonads of the broodstock mature rapidly and meet the breeding standards.

[0034] Inject exogenous hormones at a dose of 2 μg / kg, add growth regulators at a dose of 2 μg / kg per day, mix the growth regulator with the basal feed, and add it with the basal feed. Add the basal feed during the breeding period until spawning and reproduction are completed.

[0035] Among them, the exogenous hormone is the injectable fish ovulation hormone No. 2 (abbreviated as ovulation hormone No. 2), which is injected once, that is, once at the base of the pectoral fin when the ovary develops to the end of stage IV to initiate final maturation and ovulation. The signs that the ovary develops to the end of stage IV are: the volume of the ovary increases significantly, filling the entire abdominal cavity, and is light gray or light yellow; the oocyte develops to stage IV egg cells, the cell diameter is large and transparent, the yolk granules are filled with cytoplasm, the cell nucleus is marginalized, and meiosis is about to be completed.

[0036] Example 2 A method for aquatic population reproduction and seedling raising based on water temperature-hormone coordinated regulation, wherein the dosage of growth regulator is 3 μg / kg per day, and the remaining operations are the same as those in Example 1.

[0037] Example 3 A method for aquatic population propagation and seedling raising based on water temperature-hormone coordinated regulation, wherein the growth regulator is sodium butyrate, the dosage is 2 μg / kg per day, and the remaining operations are the same as those in Example 1.

[0038] Example 4 A method for aquatic population propagation and seedling raising based on water temperature-hormone coordinated regulation, wherein the growth regulator is sodium butyrate, the dosage is 3 μg / kg per day, and the remaining operations are the same as those in Example 1.

[0039] Control group 1 A method for breeding and raising aquatic populations, wherein no growth regulator is added and other operations are the same as those in Example 1.

[0040] Control group 2 A method for aquatic population breeding and seedling raising, wherein the dosage of the growth regulator butyric acid is 1 μg / kg per day, and the remaining operations are the same as those in Example 1.

[0041] Control group 3 A method for aquatic population breeding and seedling raising, wherein the dosage of the growth regulator butyric acid is 4 μg / kg per day, and the remaining operations are the same as those in Example 1.

[0042] Control group 4 A method for breeding and raising aquatic populations, wherein the growth regulator is sodium butyrate, the dosage is 1 μg / kg per day, and the remaining operations are the same as those in Example 1.

[0043] Control group 5 A method for breeding and raising aquatic populations, wherein the growth regulator is sodium butyrate, the dosage is 4 μg / kg per day, and the remaining operations are the same as those in Example 1.

[0044] See Table 1 for broodstock reproductive performance. The results show that, when the data from Examples 1-4 are compared with Control 1, which did not administer growth regulators, the time required for ovarian development to the end of Stage IV can be shortened by up to 33.33%, the spawning rate can be increased by up to 18.99%, the absolute egg load per female can be increased by up to 61.54%, the fertilization rate can be increased by up to 43.33%, the hatching rate can be increased by up to 18.84%, and the emergence rate can be increased by up to 42.5%. Controls 2-4, which were administered with either too high or too low a growth regulator dosage, respectively, showed that all reproductive performance was inferior to that of the Examples. The broodstock reproductive performance of Examples 1-4 was the best, indicating that the dosage of growth regulators has a significant impact on broodstock reproductive performance, and careful attention should be paid to the dosage of growth regulators during breeding.

[0045] Table 1 Effects of different growth regulator dosages on aquatic population reproduction

[0046] In order to explore the synergistic effects of water temperature, growth regulators and exogenous hormones, the present invention set up Example 1 and control groups 1, 6 to 11.

[0047] Control group 6 A method for breeding and raising aquatic populations comprises the following steps: (1) Selection of aquatic broodstock Three-year-old (3-year-old) amblycephalic bream individuals with healthy body shape, no disease, well-developed gonads and excellent genetic traits were selected as broodstock.

[0048] (2) Configure the breeding environment After the end of winter, the female bighead carp enters the ovarian development stage III at the beginning of spring. Water is added to the pond to increase oxygen, and the dissolved oxygen content in the water is maintained at 5 mg / L. Basic feed is added to meet the basic nutritional conditions of aquatic broodstock.

[0049] The basic feed is a mixture of the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, sodium carboxymethyl cellulose 2.00%, cellulose 0.50%.

[0050] (3) Basic feed is provided during the breeding period until spawning and reproduction are completed.

[0051] Control group 7 A method for breeding and raising aquatic populations comprises the following steps: (1) Selection of aquatic broodstock Three-year-old (3-year-old) amblycephalic bream individuals with healthy body shape, no disease, well-developed gonads and excellent genetic traits were selected as broodstock.

[0052] (2) Configure the breeding environment After the end of winter, the female bighead carp enters the ovarian development stage III at the beginning of spring. Water is added to the pond to increase oxygen, and the dissolved oxygen content in the water is maintained at 5 mg / L. Basic feed is added to meet the basic nutritional conditions of aquatic broodstock.

[0053] The basic feed is a mixture of the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, sodium carboxymethyl cellulose 2.00%, cellulose 0.50%.

[0054] (3) Water temperature control After configuring the breeding environment, release broodstock into the pond and raise the water temperature in the pond at a rate of 0.5°C per day. When the water temperature in the pond is 20°C, maintain a constant temperature until the breeding standard is reached.

[0055] Basic feed is added during the breeding period until spawning and reproduction are completed.

[0056] Control group 8 A method for breeding and raising aquatic populations comprises the following steps: (1) Selection of aquatic broodstock Three-year-old (3-year-old) amblycephalic bream individuals with healthy body shape, no disease, well-developed gonads and excellent genetic traits were selected as broodstock.

[0057] (2) Configure the breeding environment After the end of winter, the female bighead carp enters the ovarian development stage III at the beginning of spring. Water is added to the pond to increase oxygen, and the dissolved oxygen content in the water is maintained at 5 mg / L. Basic feed is added to meet the basic nutritional conditions of aquatic broodstock.

[0058] The basic feed is a mixture of the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, sodium carboxymethyl cellulose 2.00%, cellulose 0.50%.

[0059] (3) Growth regulator regulation After the breeding environment is configured, broodstock are released into the pond. On the second day, the growth regulator butyric acid is added at a dosage of 2 μg / kg per day. The growth regulator is added for three consecutive days. Basic feed is added during the breeding period until spawning and reproduction are completed.

[0060] Control group 9 A method for breeding and raising aquatic populations comprises the following steps: (1) Selection of aquatic broodstock Three-year-old (3-year-old) amblycephalic bream individuals with healthy body shape, no disease, well-developed gonads and excellent genetic traits were selected as broodstock.

[0061] (2) Configure the breeding environment After the end of winter, the female bighead carp enters the ovarian development stage III at the beginning of spring. Water is added to the pond to increase oxygen, and the dissolved oxygen content in the water is maintained at 5 mg / L. Basic feed is added to meet the basic nutritional conditions of aquatic broodstock.

[0062] The basic feed is a mixture of the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, sodium carboxymethyl cellulose 2.00%, cellulose 0.50%.

[0063] (3) Exogenous hormone regulation After the breeding environment is configured, broodstock are released into the pond and basic feed is added during the breeding period until spawning and reproduction are completed.

[0064] The exogenous hormone is ovulation hormone No. 2, which is injected once, that is, once at the base of the pectoral fin when the ovary develops to the end of stage IV to initiate final maturation and ovulation. The signs that the ovary has developed to the end of stage IV are: the volume of the ovary has increased significantly, filling the entire abdominal cavity, and is light gray or light yellow; the oocyte develops to stage IV egg cells, the cell diameter is large and transparent, the yolk granules are filled with cytoplasm, the cell nucleus is marginalized, and meiosis is about to be completed.

[0065] Control group 10 A method for breeding and raising aquatic populations comprises the following steps: (1) Selection of aquatic broodstock Three-year-old (3-year-old) amblycephalic bream individuals with healthy body shape, no disease, well-developed gonads and excellent genetic traits were selected as broodstock.

[0066] (2) Configure the breeding environment After the end of winter, the female bighead carp enters the ovarian development stage III at the beginning of spring. Water is added to the pond to increase oxygen, and the dissolved oxygen content in the water is maintained at 5 mg / L. Basic feed is added to meet the basic nutritional conditions of aquatic broodstock.

[0067] The basic feed is a mixture of the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, sodium carboxymethyl cellulose 2.00%, cellulose 0.50%.

[0068] (3) Regulation After configuring the breeding environment, broodstock are released into the pond and the water temperature in the pond is raised at a daily rate of 0.5°C. Starting from the second day of warming, the growth regulator butyric acid is added at a dosage of 2 μg / kg per day. The growth regulator is added for three consecutive days. During the warming period, the gonads of the broodstock gradually develop, making preliminary preparations for reproduction. When the water temperature in the pond is 20°C, the temperature is maintained constant. At this time, the gonads of the broodstock mature rapidly and meet the breeding standards.

[0069] Control group 11 A method for breeding and raising aquatic populations comprises the following steps: (1) Selection of aquatic broodstock Three-year-old (3-year-old) amblycephalic bream individuals with healthy body shape, no disease, well-developed gonads and excellent genetic traits were selected as broodstock.

[0070] (2) Configure the breeding environment After the end of winter, the female bighead carp enters the ovarian development stage III at the beginning of spring. Water is added to the pond to increase oxygen, and the dissolved oxygen content in the water is maintained at 5 mg / L. Basic feed is added to meet the basic nutritional conditions of aquatic broodstock.

[0071] The basic feed is a mixture of the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, sodium carboxymethyl cellulose 2.00%, cellulose 0.50%.

[0072] (3) Regulation After the breeding environment is configured, broodstock are released into the pond. On the second day, the growth regulator butyric acid is added at a dosage of 2 μg / kg per day. The growth regulator is added for three consecutive days. Basic feed is added during the breeding period until spawning and reproduction are completed.

[0073] Inject exogenous hormones at a dose of 2 μg / kg.

[0074] Among them, the exogenous hormone is ovulation hormone No. 2, which is injected once, that is, once at the base of the pectoral fin when the ovary develops to the end of stage IV to initiate final maturation and ovulation. The signs that the ovary has developed to the end of stage IV are: the volume of the ovary has increased significantly, filling the entire abdominal cavity, and is light gray or light yellow; the oocyte develops to stage IV egg cells, the cell diameter is large and transparent, the yolk granules are filled with cytoplasm, the cell nucleus is marginalized, and meiosis is about to be completed.

[0075] Among the groups in Table 2, Control Group 6, which received no water temperature adjustment, no exogenous hormone injection, and no growth regulators, had the slowest ovarian development, and the worst spawning rate and absolute egg load per female. Control Group 7, which received only water temperature adjustment, shortened ovarian development compared to Control Group 6 and also improved spawning rate and absolute egg load per female to a certain extent. Control Group 8, which received only growth regulators, achieved similar results to Control Group 7 in spawning rate and other indicators, and also improved spawning rate and other indicators to a certain extent compared to Control Group 6. Control Group 9, which received only exogenous hormones, did not significantly shorten ovarian development because it was treated at the end of ovarian stage IV. Control group 10 was the experimental group that underwent water temperature + growth regulator adjustment, control group 11 was the experimental group that underwent growth regulator + exogenous hormone adjustment, and control group 1 was the experimental group that underwent water temperature + exogenous hormone adjustment. The results showed that compared with control group 7 and control group 9, after adding growth regulators, indicators such as spawning rate were improved, and ovarian development time was shortened.

[0076] In summary, the results in Table 2 show that water temperature, exogenous hormones and growth regulators all have the effect of promoting the reproductive performance of broodstock, but the effects of single factors and double factors are not as good as the combined effect of water temperature, exogenous hormones and growth regulators.

[0077] Table 2 Comparison results of synergistic enhancement

[0078] In order to explore the effect of exogenous hormone concentration on the reproductive performance of broodstock, the present invention set up Example 1 and control groups 12 to 13.

[0079] Control group 12 A method for aquatic population breeding and seedling raising, wherein the injection dose of the exogenous hormone ovulation-stimulating hormone No. 2 is 5 μg / kg, and other operations are the same as those of the control group 1.

[0080] Control group 13 A method for breeding and raising aquatic fish stocks comprises injecting an exogenous hormone ovulation-inducing hormone No. 2 at a dose of 5 μg / kg and simultaneously injecting 1000 IU / kg of human chorionic gonadotropin, and the rest of the operations are the same as those of control group 1.

[0081] Control group 12-control group 13 is a scheme of water temperature + exogenous hormone regulation in the prior art, and the injection dose of the exogenous hormone is greater than 2 μg / kg in the embodiment of the present invention. However, after comparing the experimental results, it was found that after the growth additive was adopted in the present application, the reproductive performance was very good even with a low dose of exogenous hormone. This shows that the method of the present invention can reduce the dosage of exogenous hormones, thereby reducing the residual hormones in the aquatic body and reducing safety risks. The butyric acid and sodium butyrate used in the present invention are both relatively safe feed additives, and will degrade in water bodies for a long time, so there is no need to worry about long-term residues. Among them, sodium butyrate is a very safe substance.

[0082] Table 3 Comparison results of synergistic enhancement

[0083] In order to explore the effects of other growth regulators on the reproductive performance of broodstock, the present invention set up Example 1 and control group 14.

[0084] Control group 14 A method for breeding and raising aquatic populations, wherein poly-β-hydroxybutyrate is used as a growth regulator, and other operations are the same as those in Example 1.

[0085] Control group 14 is an experimental group containing other growth regulators commonly used in the art. The results in Table 4 show that these other prior art growth regulators were less effective than those in Example 1 of the present invention. The spawning rate, absolute egg number per female, and fertilization rate of control group 14 were all the same as those of control group 1, indicating that β-hydroxybutyrate was unable to improve these key reproductive indicators.

[0086] Table 4 Effects of other growth regulators on broodstock reproductive performance

[0087] It should be noted that when numerical ranges are involved in the present invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes preferred embodiments. Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they understand the inventive concept of the present invention, and such changes and modifications fall within the scope of the present invention.

[0088] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. If these modifications and variations of the present invention fall within the scope of the equivalent technology of the present invention, the present invention is intended to include these modifications and variations.

Claims

1. The application of growth regulators in aquatic population breeding and seedling cultivation based on water temperature-hormone coordinated regulation, characterized in that: The growth regulator is butyric acid or sodium butyrate; The growth regulator is used to enhance the effect of luteinizing hormone-releasing hormone or its analogues in promoting aquatic reproduction; The said promoting aquatic reproduction refers to promoting the growth of aquatic ovum, promoting yolk accumulation, shortening the ovarian development cycle and improving the spawning rate.

2. A method for aquatic population reproduction and seedling raising based on water temperature-hormone coordinated regulation, characterized in that: include: Select fish bred in spring as broodstock; Configure the breeding environment to provide basic nutritional conditions for the reproduction of broodstock; Water temperature and hormone coordinated regulation: At the beginning of spring, broodstock are released into the breeding environment to raise the water temperature in the pond at a rate of 0.5°C to 2.5°C per day. Starting from the second day of the temperature increase, growth regulators are added. When the water temperature in the pond is between 8°C and 30°C, the temperature is maintained constant. During this process, exogenous hormones are injected. Basic feed is added during the breeding period until spawning and reproduction are completed. Among them, the exogenous hormone is luteinizing hormone-releasing hormone or its analogues, and the injection dose of the exogenous hormone does not exceed 4 μg / kg; The growth regulator is the butyric acid or sodium butyrate according to claim 1, and the daily dosage is 2 μg / kg to 3 μg / kg.

3. The aquatic population breeding and seedling raising method based on water temperature-hormone coordinated regulation according to claim 2 is characterized in that: For broodstock bred in warm water, the temperature should be maintained at a constant value of 15℃~30℃; For broodstock bred in cold water, the temperature should be maintained constant at 8℃~14℃.

4. The aquatic population breeding and seedling raising method based on water temperature-hormone coordinated regulation according to claim 2, characterized in that: The broodstock is bream.

5. The aquatic population breeding and seedling raising method based on water temperature-hormone coordinated regulation according to claim 2 is characterized in that: The injection dose of the luteinizing hormone-releasing hormone is 2 μg / kg.

6. The aquatic population breeding and seedling raising method based on water temperature-hormone coordinated regulation according to claim 2 is characterized in that: Exogenous hormones are given as a one-time injection.

7. The aquatic population breeding and seedling raising method based on water temperature-hormone coordinated regulation according to claim 2 is characterized in that: Growth regulators are applied continuously for 3 to 5 days.

8. The aquatic population breeding and seedling raising method based on water temperature-hormone coordinated regulation according to claim 7 is characterized in that: Growth regulators are mixed into the basic feed.

9. The aquatic population breeding and seedling raising method based on water temperature-hormone coordinated regulation according to claim 2, characterized in that: The basic feed is a mixture of the following raw materials in the following mass percentages: Fish meal 12.00%, soybean meal 11.00%, rapeseed meal 10.00%, cottonseed meal 24.10%, fish oil 1.80%, soybean oil 1.80%, corn starch 14.00%, wheat flour 16.00%, corn bran 4.80%, choline 0.50%, aquaculture vitamin premix 1.50%, sodium carboxymethyl cellulose 2.00%, cellulose 0.50%.

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