A kind of oxytocin suitable for large-scale breeding of yellow eel and its efficient oxytocin method

Abstract

The present invention provides an oxytocin and an efficient oxytocin method suitable for large-scale breeding of yellow eel, belonging to the field of aquatic animal breeding technology. The present invention first found that adding an appropriate amount of cloprostenol sodium to low-dose HCG and LHRH-A2 can significantly improve the oxytocin effect of female yellow eel broodstock, and the oxytocin rate is more than 90%, the concentrated ovulation rate is more than 80% within 15h, and the effect time is effectively shortened by more than 10h, and the efficient oxytocin method in the present invention can not only reduce the number of detections of ovulation of broodstock, but also effectively prevent the situation of waste caused by over-mature development of broodstock, and the survival rate of broodstock during oxytocin is more than 95%. The oxytocin provided by the present invention is low in cost, and the oxytocin technology is efficient and practical, without complex processes and processes, and can be applied to the actual production activities of large-scale breeding of yellow eel, with important promotion significance, and it is of great significance to solve the seedling problem in the process of yellow eel industry development and subsequent breeding research work.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic animal breeding, and particularly relates to an oxytocin suitable for large-scale breeding of yellow eels and a high-efficiency oxytocin method. Background Art

[0002] Yellow eel (Monopterus albus), also known as eel, long fish, snake fish, and phosphorus-free prince, is a kind of bony fish. At present, the artificial breeding technology of yellow eel has made great breakthroughs and has been demonstrated on a large scale. However, due to the extremely low egg-carrying capacity of yellow eel broodstock and the asynchronous egg development, the egg-laying capacity of each broodstock weighing about 100g is only 500-800 eggs. To produce a sufficient number of yellow eel seedlings, a large number of female broodstock need to be induced to give birth. Many experts and scholars have also found in their research that yellow eel is different from other freshwater economic fish. It is not sensitive to HCG, LHRH and other major exogenous oxytocin hormones of fish. The injection dose is about 20 times that of carp fish (Ruan Guoliang et al. 2009). The cost of induced spawning is much higher than that of other fish, and the induced spawning effect is not good.

[0003] According to existing public reports, there is a patent (patent number: CN202210765640.6) that combines HCG, LHRH-A2 and domperidone (DOM) into an induced labor mixture to induce labor in female yellow eel broodstock, and found that the induced labor rate has been greatly improved, but the effect of this scheme is long, the ovulation time of broodstock is not concentrated, and the mortality rate is high. There are also public patents (patent number: CN202210280223.2) that synthesize endogenous luteinizing hormone analogs of yellow eels and then combine them with DOM to form a composite induced labor agent, which has a good induced labor effect, but the cost of synthetic polypeptides is high and it is difficult to apply to mass production, and the effect time of the composite induced labor agent is not concentrated, and the induced labor rate at the 60th hour is less than 50%. In addition, DOM is a white powder or oil with poor water solubility. The inventors found through experiments that after injection of yellow eel broodstock, a strong stress response will occur, and the mortality rate will increase significantly. Therefore, in order to reduce the production cost of artificial large-scale breeding of rice field eels, improve breeding efficiency, and thus promote the sustainable development of the rice field eel seed industry, it is urgent to develop an efficient and economical oxytocin and a practical and efficient oxytocin technology. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and provide an oxytocin suitable for large-scale breeding of yellow eels, so as to effectively improve the oxytocin effect, shorten the effect time, promote concentrated ovulation of broodstock, and significantly reduce the breeding cost.

[0005] Another object of the present invention is to establish a set of efficient induced labor methods applicable to the induced labor agent of the present invention, so as to reduce the number of ovulation inspections of broodstock, and effectively prevent the waste of broodstock due to over-mature gonad development, thereby improving the breeding efficiency, reducing labor consumption, and improving the survival rate of broodstock during temporary rearing. The technology is practical and efficient and can be effectively promoted.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The invention provides an oxytocin for large-scale breeding of rice field eels, which comprises 200-300 IU / kg HCG, 25-40 μg / kg LHRH-A2, 10-50 μg / kg cloprostenol sodium and 0.8-1.2 mL / kg 0.9% saline solution based on the weight of the rice field eels.

[0008] Furthermore, based on the body weight of the yellow eel, it includes HCG 200-205 IU / kg, LHRH-A2 25-40 μg / kg, cloprostenol sodium 29-31 μg / kg and 0.9% saline 0.8-1.2 mL / kg.

[0009] Furthermore, in the above formula, preferably, based on the body weight of the yellow eel, it includes HCG 200 IU / kg, LHRH-A2 25 μg / kg, cloprostenol sodium 30 μg / kg and 0.9% saline 1.0 mL / kg.

[0010] Furthermore, the rice field eel oxytocin is stored at -20°C and is thawed in an ice-water mixture and then temporarily placed in the ice-water mixture when used.

[0011] Another aspect of the present invention is to provide a kit for inducing labor in yellow eel, comprising the above-mentioned inducing labor agent. The kit may include independently packaged HCG, LHRH-A2 and cloprostenol sodium. It may also include an operating manual recording the inducing labor technology of the present invention.

[0012] Another aspect of the present invention is to provide a highly efficient method for inducing spawning suitable for large-scale breeding of yellow eels, wherein the above-mentioned oxytocin is injected into the chest of female yellow eels, and then the eels are temporarily cultured in micro-flowing water at 26-30°C.

[0013] Furthermore, based on the weight of the eel, the eel oxytocin contains 29-31 μg / kg of cloprostenol sodium.

[0014] Furthermore, after the female broodstock of Monopterus albus was injected with the Monopterus albus oxytocin, the ovulation peak of the female broodstock of Monopterus albus was concentrated at 35 to 50 hours.

[0015] Furthermore, after the female broodstock of rice field eels are injected with the induced fertility agent of rice field eels, the induced fertility rate of the female broodstock of rice field eels is 90% to 95%.

[0016] Furthermore, after the female broodstock of yellow eel are injected with the yellow eel oxytocin, the concentrated ovulation rate of the female broodstock of yellow eel within 15 hours exceeds 80%.

[0017] The highly efficient induced spawning technology for large-scale breeding of rice field eels established according to the induced spawning agent and induced spawning method developed by the present invention is as follows:

[0018] Inducing spawning in broodstock: Inject the above-mentioned oxytocin into the chest of female yellow eel broodstock and temporarily place them in micro-flowing water at 26-30℃.

[0019] The method for checking broodstock ovulation is:

[0020] Place the female broodstock in water and stroke the abdomen of the broodstock with your hand to feel the state of the eggs on the abdomen. If the eggs on the abdomen have a clear rolling feeling, it means that the broodstock has ovulated; if it feels like a bumpy granular feeling during inspection, it means that the broodstock has not ovulated yet and needs to be kept temporarily.

[0021] The process of broodstock ovulation inspection is as follows:

[0022] It is forbidden to inspect or disturb the broodstock within 20 hours of temporary rearing to avoid affecting the normal development of their gonads;

[0023] During the 20th to 35th hour of temporary rearing, check the ovulation of the broodstock every 5 hours. During this stage, check the broodstock with better gonad development to avoid premature ovulation and miss the best fertilization time.

[0024] During the 35th to 50th hour of temporary rearing, which is the peak period of broodstock ovulation, check the broodstock ovulation status every 3 hours;

[0025] During the 50th to 90th hour of temporary rearing, check the ovulation status of the broodstock every 5 hours. This stage is mainly for broodstock with poor gonadal development.

[0026] After 90 hours of temporary rearing, the remaining broodstock that have not ovulated will be handled separately and will no longer be reared in order to improve the breeding efficiency of the eels.

[0027] HCG, whose Chinese name is human chorionic gonadotropin, is a glycoprotein hormone extracted from the urine of pregnant women, with a relative molecular mass of about 36,000. It is a white, off-white or light yellow powder, easily soluble in water, easily deteriorated by heat and moisture absorption, and needs to be stored in a low-temperature and dry environment.

[0028] LHRH-A2, luteinizing hormone releasing hormone analogue No. 2, is a white powder that is easily soluble in water. It directly acts on the pituitary gland of fish and has a good ripening and induced production effect on major farmed fish.

[0029] Cloprostenol sodium, also known as sodium prostaglandin, sodium cloprostenol, and sodium cloprostenol, is an analog of prostaglandin F2α. During the research process, the applicant first discovered that by adding cloprostenol sodium to low-dose HCG and LHRH-A2, the induced spawning rate of female eel broodstock can be significantly improved, and the ovulation time after induced spawning is concentrated, and the empty egg rate is high. The reason may be that cloprostenol sodium can also participate in the ovulation activity of female eels, enhance the induction effect of related hormones in their bodies on ovulation, and thus promote ovulation.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The induced spawning agent for large-scale breeding of yellow eels provided by the present invention has an induced spawning rate of more than 90% for female broodstock in large-scale induced spawning operations, and the effect time is shortened by more than 10 hours compared with conventional induced spawning mixtures, and the concentrated ovulation rate of female broodstock within 15 hours exceeds 80%.

[0032] (2) The supporting induced spawning technology established by the present invention can not only significantly reduce the frequency of technicians' inspections on the ovulation of female broodstock, reduce the stress response of rice field eels, and improve the survival rate of female broodstock during temporary rearing, but also reduce the waste of broodstock, while saving manpower and reducing labor costs.

[0033] (3) The dosage levels of HCG and LHRH-A2 used in the rice field eel oxytocin provided by the present invention are relatively low, and the added cloprostenol sodium is inexpensive, thus being able to significantly reduce the production cost of rice field eel breeding. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a comparison chart of the induced spawning rates of different oxytocin agents on female yellow eel broodstock;

[0035] Figure 2 This is a comparison chart of the number of ovulations at different time points after different oxytocin-induced female yellow eel broodstock;

[0036] Figure 3 This is a comparison chart of the concentrated ovulation rate of female yellow eel broodstock treated with different oxytocin agents;

[0037] Figure 4 This is a comparison chart of the mortality rate during the induced spawning period after female yellow eel broodstock were induced to spawn by different oxytocin. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] Unless otherwise specified, the reagents or materials used in the technical solutions provided by the present invention can be obtained commercially.

[0040] In order to better illustrate the induced spawning effect of the induced spawning agent provided by the present invention on female yellow eel broodstock, the applicant conducted the following experiments and applications:

[0041] Example 1

[0042] This embodiment provides a oxytocin for inducing the spawning of 5 kg of female yellow eel broodstock, which is composed of the following:

[0043] Sodium chlorprostol: 0.05mg; HCG: 1000IU; LHRH-A2: 0.125mg; 0.9% normal saline: 5ml.

[0044] The preparation and storage methods are as follows:

[0045] Dissolve 0.05 mg of chloroprostol sodium, 1000 IU of HCG and 0.125 mg of LHRH-A2 in 5 ml of 0.9% saline and transfer to a 10 ml centrifuge tube. After preparation, shake gently, tighten the cap of the centrifuge tube and immediately store in a -20°C freezer.

[0046] Example 2

[0047] This embodiment provides a oxytocin for inducing the spawning of 5 kg of female yellow eel broodstock, which is composed of the following:

[0048] Sodium chlorprostol: 0.15mg; HCG: 1000IU; LHRH-A2: 0.125mg; 0.9% normal saline: 5ml.

[0049] Its preparation and storage method are consistent with Example 1.

[0050] Example 3

[0051] This embodiment provides a oxytocin for inducing the spawning of 5 kg of female yellow eel broodstock, which is composed of the following:

[0052] Sodium chlorprostol: 0.145mg; HCG: 1010IU; LHRH-A2: 0.20mg; 0.9% normal saline: 5ml.

[0053] Its preparation and storage method are consistent with Example 1.

[0054] Example 4

[0055] This embodiment provides a oxytocin for inducing the spawning of 5 kg of female yellow eel broodstock, which is composed of the following:

[0056] Sodium chlorprostol: 0.155mg; HCG: 1000IU; LHRH-A2: 0.13mg; 0.9% normal saline: 1ml.

[0057] Its preparation and storage method are consistent with Example 1.

[0058] Example 5

[0059] This embodiment provides a oxytocin for inducing the spawning of 5 kg of female yellow eel broodstock, which is composed of the following:

[0060] Sodium chlorprostol: 0.25mg; HCG: 1500IU; LHRH-A2: 0.15mg; 0.9% normal saline: 5ml.

[0061] Its preparation and storage method are consistent with Example 1.

[0062] Comparative Example 1

[0063] This embodiment provides a oxytocin for inducing the spawning of 5 kg of female yellow eel broodstock, which is composed of the following:

[0064] HCG: 1000IU; LHRH-A2: 0.15mg; 0.9% saline: 5ml.

[0065] Comparative Example 2

[0066] This embodiment provides a oxytocin for inducing the spawning of 5 kg of female yellow eel broodstock, which is composed of the following:

[0067] Sodium cloprostol: 0.15 mg; 0.9% saline: 5 ml.

[0068] Comparative Example 3

[0069] This embodiment provides a oxytocin for inducing the spawning of 5 kg of female yellow eel broodstock, which is composed of the following:

[0070] Sodium cloprostol: 0.3 mg; 0.9% saline: 5 ml.

[0071] Example 6

[0072] Experimental study on the effects of different oxytocin on spawning of female yellow eel broodstock

[0073] 1. Test materials

[0074] Female broodstock of yellow eel were purchased from Baishazhou Aquatic Products Wholesale Market in Wuhan. The selection size of female broodstock was 45-60g, and the abdomen was required to be swollen, soft and elastic. After the broodstock were selected, they were transported to the induced spawning workshop (the new aquatic training base of Huazhong Agricultural University).

[0075] 2. Test methods

[0076] 2.1 Broodstock induction

[0077] The selected broodstock were randomly divided into four groups, each group with 100 eels. The test group was injected with the oxytocin of different compatibility ratios described in Examples 1 to 5, and the control group was injected with the oxytocin described in Comparative Examples 1 to 3, and the injection dose for each eel was 0.05 ml. After the induced spawning was completed, the four groups of eels were placed in different cages of the same broodstock temporary rearing pond, and relevant marks were made. During the temporary rearing period, micro-flow water was maintained and the water temperature was controlled between 26-30°C.

[0078] 2.2 Broodstock ovulation inspection method

[0079] Place the female broodstock in water and stroke the abdomen of the broodstock with your hand to feel the state of the eggs in the abdomen. If the eggs in the abdomen can flow with the fingertips and have a clear rolling feeling, it means that the broodstock has ovulated; if the fingertips sliding up and down feel a bumpy granular feeling and the eggs do not flow, it means that the broodstock has not ovulated yet and needs to be kept temporarily.

[0080] 2.3 Broodstock ovulation inspection process

[0081] After inducing spawning, it is forbidden to check or disturb the female broodstock within 20 hours of temporary rearing to avoid stress affecting the normal development of gonads. During the 20th to 35th hour of temporary rearing, check the ovulation of the broodstock every 5 hours. During this stage, check the broodstock with better gonad development to avoid missing the best fertilization time due to early ovulation; during the 35th to 50th hour of temporary rearing, check the ovulation of the broodstock every 3 hours. This stage is the peak period of induced spawning, so the inspection frequency needs to be appropriately increased; during the 50th to 90th hour of temporary rearing, check the ovulation of the broodstock every 5 hours. This stage is mainly for broodstock with poor gonad development; after 90 hours of temporary rearing, the remaining female broodstock that have not ovulated will be handled separately and will not continue to be reared.

[0082] 3. Evaluation indicators of induced labor effect

[0083] During the 90-hour temporary rearing period, each ovulation inspection of female broodstock requires detailed statistics on the number of broodstock that ovulate in each group, as well as the number of female broodstock that die during the temporary rearing period, and calculation of the induced spawning rate, concentrated ovulation rate and mortality rate of each group of female broodstock.

[0084] Ovulation induction rate (%) = (number of ovulated female broodstock during the temporary rearing period (within 90 hours) / total number of induced female broodstock) × 100%, used to indicate the overall induced ovulation effect of the oxytocin;

[0085] Concentrated ovulation rate (%) = (number of ovulated female broodstock in a certain 15-hour period during temporary rearing / total number of induced female broodstock) × 100%, used to indicate the uniformity of broodstock effect time. The higher the concentrated ovulation rate, the more concentrated the effect time is and the better the induced spawning effect is.

[0086] Mortality rate (%) = (number of female broodstock that died during the temporary rearing period / total number of female broodstock that underwent induced spawning) × 100%, which is used to reflect the mortality of broodstock during the temporary rearing period after induced spawning.

[0087] 4. Analysis of test results

[0088] refer to Figure 1 , it can be seen from the induced labor rate of each group of female yellow eel broodstock that the induced labor rate of the test group is much higher than that of comparative example 1. Among them, Example 2 has the highest induced labor rate of 93%, and Example 3 and Example 4 are second only to Example 2, with induced labor rates of 89% and 91%, respectively. The induced labor rate of Example 5 is 84%, while the induced labor rate of Example 1 is slightly lower, at 78%, and the induced labor rate of comparative example 1 is 46%. Obviously, the induced labor rate of Example 2 is about twice that of comparative example 1. The induced labor rates of comparative examples 2 and 3 are extremely low, only 10% and 8%, respectively.

[0089] refer to Figure 2 The number of ovulations of female eel broodstock in each group at different time points, and Figure 3 It can be seen from the concentrated ovulation rate of female yellow eel broodstock that after the injection of exogenous oxytocin, both the test group and the control group have an ovulation peak stage. The ovulation peaks of Examples 2, 3, 4, and 5 are all concentrated in the 35-50h stage, among which the concentrated ovulation rate of Example 2 within 15h exceeds 80%, and the concentrated ovulation rate of Examples 3 and 4 within 15h is within the range of 70%-80%, but the concentrated ovulation rate of Example 5 within 15h is lower than 70%; the ovulation peak of female yellow eel broodstock in Example 1 is concentrated in the 41-55h stage, and the concentrated ovulation rate within 15 is lower than 50%; the ovulation peak of Comparative Example 1 is concentrated in 50-65h, and the concentrated ovulation rate within 15h is lower than 20%, and the induced ovulation effect is much different from that of the examples. The ovulation time and concentrated ovulation rate of Comparative Example 2 and Comparative Example 3 are similar, and the ovulation time is within 35h after induced ovulation. I also found in the induction experiment that the gonads of broodstock that ovulated within 35 hours were in excellent condition, while the gonads of broodstock that did not ovulate after 35 hours would degenerate to varying degrees, with their soft and elastic abdomen gradually becoming flat and hard, indicating that injecting cloprostenol sodium alone has no induction effect on rice field eels.

[0090] refer to Figure 4It can be seen that the mortality rate during the temporary rearing of broodstock is the lowest in Example 3, which is 3%, followed by Example 2 and Example 4, and the mortality rate of both groups is 3%. The mortality rate of Example 5 is higher than that of Example 1, which may be due to the high dosage of cloprostenol sodium in the oxytocin of Example 5, which has a greater irritation to the broodstock of yellow eel. In this test, the mortality rate of Comparative Example 1 is the highest, which is 11%, which may be due to the short effect time of the test group, the concentrated ovulation time, and the number of times to check whether ovulation is much lower than that of the control group, so the mortality rate of yellow eel broodstock in each test group during ovulation is lower than that of the control group. The mortality rate of Comparative Example 2 and Comparative Example 3 during the induced labor period is similar to that of the control group, indicating that cloprostenol sodium is less irritating to yellow eel and will not increase the mortality rate of broodstock.

[0091] As can be seen from the above, cloprostenol sodium does not have an induced labor effect on the eel, but has an excellent auxiliary effect. Adding cloprostenol sodium to the induced labor agent can greatly increase the induced labor rate of female eel broodstock, shorten the effect time, and the concentrated ovulation rate is higher, the mortality rate of broodstock during temporary rearing is lower, and the induced labor effect is much higher than that of the control group. In addition, different compatibility doses also have a great influence on the induced labor effect of female eel broodstock. In this experiment, the induced labor effect of the induced labor agent compatibility of Example 2 is the best.

[0092] Example 7

[0093] Experiment on the large-scale breeding and production of yellow eel

[0094] The production trial was conducted at Jinxian Agriculture Co., Ltd. in Jinxian County, Nanchang City, Jiangxi Province. The trial was conducted from May 3 to June 3. A total of 8 batches of induced spawning and reproduction trials were conducted, with a total of 1,377 kg of female eel broodstock induced.

[0095] 1. Test materials

[0096] 1.1 Trial Drugs

[0097] The composition of the oxytocin for inducing spawning of 1500kg female yellow eel broodstock is: cloprostenol sodium: 45mg; HCG: 300,000 IU; LHRH-A2: 37.5mg; 0.9% physiological saline: 1500ml; after preparation, it is cryopreserved at low temperature.

[0098] 1.2 Experimental fish

[0099] The female yellow eel broodstock used in the experiment were selected from Jinxian County, Jiangxi Province and its surrounding counties and cities.

[0100] 2. Test methods

[0101] 2.1 Methods of broodstock induction

[0102] First, the prepared oxytocin is placed in a mixture of ice and water to thaw. After thawing, the oxytocin injection dose is 1 ml / kg based on the weight of the eel. After induced spawning, the broodstock are temporarily raised in micro-flowing water, and the water temperature is controlled between 26-30°C.

[0103] 2.2 Broodstock ovulation inspection method

[0104] Place the female broodstock in water and stroke the abdomen of the broodstock with your hand to feel the state of the eggs in the abdomen. If the eggs in the abdomen can flow with the fingertips and have a clear rolling feeling, it means that the broodstock has ovulated; if the fingertips sliding up and down feel a bumpy granular feeling and the eggs do not flow, it means that the broodstock has not ovulated yet and needs to be kept temporarily.

[0105] 2.3 Broodstock ovulation inspection process

[0106] After induction of labor, it is forbidden to check or disturb the female broodstock within 20 hours of temporary rearing to avoid stress affecting the normal development of gonads; during the 20th-35th hour of temporary rearing, check the ovulation of the broodstock every 5 hours. During this stage, the main checkpoints are for broodstock with better gonad development to avoid premature ovulation and missing the best fertilization time; during the 35th-50th hour of temporary rearing, check the ovulation of the broodstock every 3 hours. This stage is the peak period of induction of labor, so the inspection frequency needs to be appropriately increased; during the 50th-90th hour of temporary rearing, check the ovulation of the broodstock every 5 hours. This stage is mainly for broodstock with poor gonad development; after 90 hours of temporary rearing, the remaining female broodstock that have not ovulated will be handled separately and will not be reared any longer.

[0107] 3. Evaluation indicators of induced labor effect

[0108] During the 90-hour temporary rearing period, each ovulation inspection of female broodstock requires detailed statistics on the number of broodstock that ovulate in each group, as well as the number of female broodstock that die during the temporary rearing period, and calculation of the induced spawning rate, concentrated ovulation rate and mortality rate of each group of female broodstock.

[0109] Ovulation induction rate (%) = (number of ovulated female broodstock during the temporary rearing period (within 90 hours) / total number of induced female broodstock) × 100%, used to indicate the overall induced ovulation effect of the oxytocin;

[0110] Concentrated ovulation rate (%) = (number of ovulated female broodstock in a certain 15-hour period during temporary rearing / total number of induced female broodstock) × 100%, used to indicate the uniformity of broodstock effect time. The higher the concentrated ovulation rate, the more concentrated the effect time is and the better the induced spawning effect is.

[0111] Mortality rate (%) = (number of female broodstock that died during the temporary rearing period / total number of female broodstock that underwent induced spawning) × 100%, which is used to reflect the mortality of broodstock during the temporary rearing period after induced spawning.

[0112] 4. Analysis and discussion of test results

[0113] From the induced spawning effects of each batch in Table 1, it can be seen that the induced spawning rates of different batches have certain differences, but they are all above 90%. Among them, the first batch has the lowest induced spawning rate, which is 90.39%, and the eighth batch has the highest induced spawning rate, which is as high as 95.02%. The reason may be that the induced spawning time of the first batch of broodstock is in the early stage of the eel breeding period, and the gonad development is poor, while the eighth batch is at the peak of the eel breeding period, and the gonad development is optimal, so the induced spawning rate is the highest. In this experiment, the peak ovulation period of broodstock of different batches is in the 35-50h interval, and the highest concentrated ovulation rate is 86.10%. The mortality rate of broodstock during temporary rearing is as high as 4.79% and as low as 1.28%, so the survival rate of broodstock during temporary rearing is above 95%.

[0114] From the induction effect of the production test in Table 2, it can be seen that in this large-scale breeding production test, a total of 1,377 kg of broodstock were induced to spawn, the average induction rate was 92.34%, the average concentrated ovulation rate was 83.02%, the average mortality rate during the temporary rearing period was 2.81%, and the breeding effect was excellent.

[0115] Table 1. Effect of each batch of induced labor

[0116]

[0117]

[0118] Table 2. Effect of induced production in production test

[0119]

[0120] 5. Conclusion

[0121] The oxytocin provided by the present invention has excellent oxytocin effect in large-scale production, with a oxytocin rate of more than 90%, a concentrated ovulation rate of more than 80%, and a mortality rate of less than 5% during temporary rearing of broodstock. It can effectively and significantly reduce the breeding cost of yellow eels, reduce work intensity, and save labor, and is very suitable for large-scale breeding and production of yellow eels.

[0122] Example 8

[0123] This embodiment provides a kit suitable for large-scale breeding of yellow eel.

[0124] The kit includes independently packaged HCG, LHRH-A2 and chlorprostol sodium, wherein the HCG is 200-300 IU / kg, the LHRH-A2 is 25-40 μg / kg, and the chlorprostol sodium is 10-50 μg / kg based on the weight of the yellow eel. It also includes an operating manual for the induction method.

[0125] The specific instructions for use are as follows:

[0126] According to the weight of the eel, HCG 200-300IU / kg, LHRH-A2 25-40μg / kg, chlorprostol sodium 10-50μg / kg, are prepared with 0.9% saline, and the amount of saline is 0.8-1.2mL / kg. After preparation, it should be immediately placed in a -20℃ refrigerator for frozen storage. When using, the frozen oxytocin should be placed in an ice-water mixture for thawing and temporary storage to prevent it from becoming ineffective due to excessive temperature.

[0127] Inducing spawning in broodstock: Inject 0.05 mL into the chest of female broodstock of yellow eel, and place them in micro-flowing water at 26-30℃ for temporary storage after injection.

[0128] Broodstock inspection method: Place the female broodstock in water and stroke the abdomen of the broodstock with your hand to feel the state of the eggs in the abdomen. If the eggs in the abdomen can flow with the stroke of the fingertips and have an obvious rolling feeling, it means that the broodstock has ovulated and artificial insemination needs to be performed immediately; if the fingertips feel a concave and convex granular feeling during the inspection and the eggs do not flow, it means that the broodstock has not ovulated and needs to be kept temporarily.

[0129] Broodstock inspection process:

[0130] It is forbidden to inspect or disturb the female broodstock within 20 hours of temporary rearing to avoid affecting the normal development of the gonads;

[0131] During the 20th to 35th hour of temporary rearing, check the ovulation of the broodstock every 5 hours. During this stage, check the broodstock with better gonad development to avoid premature ovulation and miss the best fertilization time.

[0132] During the 35th to 50th hour of temporary rearing, which is the peak period of broodstock ovulation, check the broodstock ovulation status every 3 hours;

[0133] During the 50th to 90th hour of temporary rearing, check the ovulation status of the broodstock every 5 hours. This stage is mainly for broodstock with poor gonadal development.

[0134] After 90 hours of temporary rearing, the remaining female broodstock that have not ovulated will be handled separately and will not be reared any further in order to improve breeding efficiency.

[0135] For matters not mentioned above, the prior art applies.

[0136] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art to which the present invention belongs may make various modifications or supplements to the described specific embodiments or replace them in a similar manner, but they will not deviate from the direction of the present invention or exceed the scope defined by the attached claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc. made to the above implementations based on the technical essence of the present invention should be included in the protection scope of the present invention.

Claims

1. An oxytocin suitable for large-scale breeding of rice field eels, characterized in that: Measured based on the weight of the yellow eel, it includes 200-300 IU / kg of human chorionic gonadotropin (HCG), 25-40 μg / kg of gonadotropin-releasing hormone A2 (LHRH-A2), 10-50 μg / kg of cloprostenol sodium and 0.8-1.2 ml / kg of 0.9% normal saline.

2. The oxytocin according to claim 1, characterized in that Calculated based on the body weight of the yellow eel, it includes HCG 200-205 IU / kg, LHRH-A2 25-40 μg / kg, cloprostenol sodium 29-31 μg / kg and 0.9% saline 0.8-1.2 ml / kg.

3. The oxytocin according to claim 2, characterized in that The oxytocin is stored at -20°C and is thawed in an ice-water mixture before use and then temporarily placed in the ice-water mixture.

4. Use of the oxytocin as described in any one of claims 1-3 in artificial induced spawning of rice field eel.

5. A kit for inducing spawning of rice field eels, characterized in that: The invention comprises the oxytocic agent as described in any one of claims 1 to 3.

6. An efficient method for inducing spawning of large-scale breeding of rice field eels, characterized in that: The oxytocin as claimed in any one of claims 1 to 3 is injected into the chest of the female yellow eel, and then the female eel is temporarily cultured in micro-flowing water at 26 to 30°C.

7. The efficient method for inducing labor as claimed in claim 6, characterized in that: Calculated by the weight of the rice field eel, the rice field eel oxytocin contains 29-31 μg / kg of cloprostenol sodium.

8. The efficient method for inducing labor as claimed in claim 7, characterized in that: After the female broodstock of Monopterus albus is injected with the oxytocin for Monopterus albus, the ovulation peak of the female broodstock of Monopterus albus is concentrated at 35 to 50 hours.

9. The efficient method for inducing labor as claimed in claim 7, characterized in that: After the female broodstock of yellow eel are injected with the yellow eel induced labor agent, the induced labor rate of the female broodstock of yellow eel is 90% to 95%.

10. The efficient method for inducing labor as claimed in claim 7, characterized in that: After the female broodstock of yellow eel are injected with the yellow eel oxytocin, the concentrated ovulation rate of the female broodstock of yellow eel within 15 hours exceeds 80%.

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