Method for improving regular insemination effect of replacement gilts

Abstract

The invention belongs to the technical field of livestock breeding, and discloses a method for improving the timed insemination effect of replacement gilts, the replacement gilts of the right age are selected, 900-1100 IU PMSG is intramuscularly injected, a timed insemination procedure is started to be implemented after 15-18 days, and the timed insemination procedure comprises the following operation processes that altrenogest with the dosage of 20 mg / sow / day is continuously fed for 12 days, and then the replacement gilts of the right age are continuously fed for 12 days; after feeding of altrenogest is stopped for 42 h, PMSG of 900-1100 IU / head is subjected to intramuscular injection, GnRH of 100 micrograms / head is subjected to intramuscular injection after 80 h, first-time artificial insemination is carried out after 24 h, and second-time artificial insemination is carried out after 16 h. The invention discloses a method for improving the timed insemination effect of replacement gilts, which breaks through the conventional technical cognition, shortens the feeding time of altrenogest from 18 days to 12 days, not only obviously increases the oestrus uniformity of the replacement gilts and improves the hormone secretion condition of the replacement gilts, but also achieves the effect of improving the uterus development state of the gilts. A better environment is effectively provided for embryo development, and embryo growth is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of livestock breeding, and in particular to a method for improving the effect of timed insemination of gilts. Background Art

[0002] Gilts provide reserve resources for the virtuous cycle of pig farms. Studies have shown that 10% to 30% of gilts have latent estrus, and the anestrus rate is 15% to 20%, while most of these sows with latent estrus can ovulate as usual. Therefore, it is urgent to improve and innovate the conventional estrus identification and artificial insemination breeding methods to improve the current status of sow production management and adapt to the development needs of the breeding industry.

[0003] Timed insemination of sows is an innovative technology that is a combination of artificial insemination and synchronized estrus technology. It regulates the secretion of reproductive hormones in sows by adding exogenous synthetic hormones, thereby regulating the development of follicles, so that a large number of sows show estrus symptoms and ovulate in a specific time, and sows are inseminated and bred in batches. This technology can reduce the dependence on estrus detection, reduce production losses caused by latent estrus, increase the number of births per year in sows, and improve the reproductive utilization rate of sows. It is conducive to batch production and epidemic prevention and disinfection of pig herds, and reduce cross-infection of epidemic diseases. However, the timed insemination technology has been introduced into my country for a short time, and there are problems such as unstable effects and unclear increase in the number of embryos, which need to be studied and solved in depth.

[0004] Prior art 1: Chinese patent 202010640013.0 discloses a method for improving the efficiency of timed insemination of gilts. Healthy gilts of appropriate age are selected, and PMSG 1000IU / head is injected intramuscularly. The timed insemination procedure is implemented after 15-20 days. In the early stage of the conventional timed insemination procedure, the gilts are pretreated with PMSG to provide the sows with a follicle development process, so that the gilts are in a known estrus before the conventional timed insemination procedure, that is, the follicle luteal phase starts at 15 days, and the follicle development phase starts at 20 days. The initial follicle development state of the entire group is consistent and controllable.

[0005] The above technology effectively compensates for the deficiencies of the existing timed insemination program by processing the timed insemination program of gilts, optimizes the existing timed insemination program, improves the reproductive performance of gilts, and thus increases the economic benefits of the pig farm.

[0006] However, this technology does not study embryonic growth during sow reproduction. The core requirement of sow production is to breed healthy piglets, thereby reducing the disease rate of piglets or avoiding developmental defects in piglets, and reducing the cost of maintaining pig health in the breeding industry. Summary of the invention

[0007] One of the objectives of the present invention is to provide a method for improving the timed insemination effect of replacement gilts. By adjusting the feeding days of allyl trenbolone, the uterine development status of sows is improved while shortening the allyl trenbolone cycle, thereby affecting the embryo growth and providing a better environment for embryo development.

[0008] To achieve the above objective, the present invention provides a method for improving the timed insemination effect of replacement gilts. Select suitable-age replacement gilts, intramuscularly inject 900 - 1100 IU / head of PMSG, and start the timed insemination program 15 - 18 days later. The operation process of the timed insemination program is as follows: continuously feed allyl trenbolone at a dose of 20 mg / head / day for 12 days, intramuscularly inject 900 - 1100 IU / head of PMSG 42 h after stopping the feeding of allyl trenbolone, intramuscularly inject 100 μg / head of GnRH 80 h later, perform the first artificial insemination 24 h later, and perform the second artificial insemination 16 h later.

[0009] As a preferred technical solution, the method for improving the timed insemination effect of replacement gilts is: select suitable-age replacement gilts, intramuscularly inject 1000 IU / head of PMSG, and start the timed insemination program 15 days later. The operation process of the timed insemination program is as follows: continuously feed allyl trenbolone at a dose of 20 mg / head / day for 12 days, intramuscularly inject 1000 IU / head of PMSG 42 h after stopping the feeding of allyl trenbolone, intramuscularly inject 100 μg / head of GnRH 80 h later, perform the first artificial insemination 24 h later, and perform the second artificial insemination 16 h later.

[0010] The present invention injects PMSG 15 days before the existing precise timed insemination program and shortens the subsequent feeding time of ALT (i.e., allyl trenbolone) from 18 days to 12 days, which can significantly increase the estrus uniformity of replacement gilts, improve the uterine development status of sows, and improve the hormone secretion of replacement gilts.

[0011] Especially for the uterine development status of sows, it has been found through research that when the feeding time of allyl trenbolone is shortened from 18 days to 12 days, on the 16th day of pregnancy of sows, the uterine horn length is significantly better than the scheme of feeding for 18 days, and the microvessels in the lamina propria of the endometrium are denser and richer than those in the FTAI group. The gland abundance in the lamina propria is increased and distributed on both the basal side and the uterine cavity side. At the same time, the development of the glands is more developed, and more endometrial glands are linear or strip-shaped, providing a better environment for embryo development.

[0012] Furthermore, 10 μg of oxytocin is added to the semen used for the first artificial insemination and the second artificial insemination.

[0013] Preferably, the suitable-age replacement gilts are replacement gilts at 210 ± 10 days of age.

[0014] More preferably, the suitable gilts are Duroc gilts.

[0015] Beneficial effects

[0016] Compared with the prior art, the present invention has at least the following advantages:

[0017] (1) The present invention discloses a method for improving the timed insemination effect of gilts, breaking the conventional technical understanding, shortening the feeding time of allyl progesterone from 18 days to 12 days, not only significantly increasing the estrus uniformity of gilts, improving the hormone secretion of gilts, but also having the effect of improving the uterine development state of sows, effectively providing a better environment for embryo development and promoting embryo growth;

[0018] (2) The method of the present invention can more effectively promote the follicular development of gilts, thereby increasing the conception probability and helping to maintain pregnancy stability;

[0019] (3) The method of the present invention can increase the P4 level, thereby stimulating the proliferation of the endometrium and playing a role in maintaining it in the early stage of pregnancy, being beneficial to uterine development, embryo implantation, development and pregnancy maintenance. Brief description of the drawings

[0020] The present invention will be further described below in conjunction with the drawings and embodiments;

[0021] Figure 1 It is the determination result of the hormone content in the blood of sows 42 hours after stopping feeding allyl progesterone in the improved group and the control group of the present invention;

[0022] Figure 2 It is the determination result of the hormone content in the blood of sows on the slaughter day in the improved group and the control group of the present invention;

[0023] Figure 3 It is the result of the uterine development of sows on the slaughter day in the improved group and the control group of the present invention;

[0024] Figure 4 It is the HE staining result diagram of sows on the slaughter day in the improved group and the control group of the present invention. Detailed implementation manners

[0025] The present invention will be further described below in conjunction with the embodiments, but it does not constitute any limitation to the present invention. Any limited modifications made within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0026] In order to elaborate on the technical content of the present invention in detail, the following further description is made in conjunction with the implementation manners.

[0027] 1 Experimental animals

[0028] Twelve Duroc replacement gilts aged 210 (±3) days and weighing about 110 kg were randomly selected as experimental animals.

[0029] 2 Experimental grouping and procedures

[0030] (1) Grouping: ① Control group, using the existing FTAI program; ② Improved group, changing the ALT feeding for 18 days in the existing FTAI program to 12 days, and adding oxytocin at 10 μg / head / time during artificial insemination; other treatments were the same.

[0031] Existing FTAI program: Intramuscular injection of PMSG at 1000 IU / head, and on the 15th day, allyl trenbolone (ALT) was fed at 3 pm every day, with a feeding dose of 20 mg / head / d for 18 consecutive days. After stopping the ALT feeding for 42 h, PMSG at 1000 IU / head was intramuscularly injected into the replacement gilts. After 80 h, gonadotropin-releasing hormone (GnRH) at 200 μg / head was intramuscularly injected, and the first artificial insemination was performed 24 h later, and the second artificial insemination was performed 16 h later.

[0032] (2) Experimental process:

[0033] 1) Before allyl trenbolone feeding: Both the control group and the improved group (ALT12) were intramuscularly injected with 1000 IU PMSG.

[0034] 2) Feeding of allyl trenbolone at 20 mg / head / day: The improved group was continuously fed for 12 days, and the control group was continuously fed for 18 days.

[0035] 3) Before artificial insemination after stopping allyl trenbolone feeding: The treatments of the two groups were the same, that is, after stopping allyl trenbolone feeding for 42 h, 1000 IU PMSG was intramuscularly injected, and 100 μg GnRH was intramuscularly injected after 80 h.

[0036] 4) Artificial insemination: Artificial insemination was performed once at 24 h and 40 h after injecting GnRH; during insemination, 10 μg / head / time was added in the improved group and not added in the control group.

[0037] Blood samples from the anterior vena cava of the sows were collected at 42 h after stopping allyl trenbolone feeding and at 16 days of pregnancy for detecting the contents of FSH, LH, E2, and P4 in plasma; the experimental sows were sacrificed at 16 days and 24 days of pregnancy for detecting the uterine horn length, uterine development status, and embryo number; the estrus rate, breeding rate, and conception rate of the sows were counted.

[0038] 3 Collection and detection of samples

[0039] (1) Determination of hormone content in blood: Anterior vena cava blood samples (5 ml / head) were collected at 42 h after stopping feeding allylgestin (randomly selecting 7 pigs) and on the day of slaughter (randomly selecting 3 pigs), placed in heparin sodium anticoagulant tubes, centrifuged at 1500 rpm for 10 min after mixing, and the plasma was stored at -80 °C until the samples were sent; the samples were sent to Beijing Northern Biotechnology Research Institute Co., Ltd. to detect the hormone levels of sows at each stage by radioimmunoassay.

[0040] The improved group and the control group were measured according to this method, and the results are shown in Table 1 and Figure 1 、 Figure 2 as follows: In the figure, FSH is follicle-stimulating hormone, LH is luteinizing hormone, E2 is estrogen, and P4 is progesterone;

[0041] Table 1 Results of determination of hormone content in the blood of sows in the improved group and the control group

[0042]

[0043] According to Table 1, Figure 1 and Figure 2 the results show that:

[0044] The estrogen level of the sows in the improved group of the present invention is significantly higher than that of the control group, indicating that after shortening the feeding days of allylgestin to 12 days in the present invention, it can effectively stimulate follicle growth, stimulate endometrial development, regulate the estrus cycle, and thus improve the uniformity of estrus of sows.

[0045] At the same time, the levels of progesterone, follicle-stimulating hormone and luteinizing hormone in the sows of the improved group of the present invention tend to be higher than those of the control group, but the difference is not significant, which is consistent with the better development state of the endometrium in the early pregnancy.

[0046] The improved group of the present invention can significantly increase the progesterone content 16 days after the pregnancy of the replacement sows, which is more conducive to the maintenance of embryo development.

[0047] (2) Statistics of sow estrus situation: The estrus rate, insemination rate and conception rate of sows were counted. Among them, the estrus rate is the proportion of sows showing estrus characteristics before artificial insemination in the experimental group of sows; all sows were inseminated in the experiment, and the insemination rate of sows was 100%; the conception rate is the proportion of pregnant sows in the inseminated sows.

[0048] The improved group and the control group were statistically analyzed according to this method, and the results are shown in Table 2;

[0049] Table 2 Estrus and parturition conditions of different timed insemination methods for replacement sows

[0050]

[0051] According to the results in Table 2, it can be seen that:

[0052] By adjusting the feeding days of altrenogest and adding oxytocin to the semen, the present invention can effectively improve the estrus rate and conception rate of sows, and effectively improve the synchronization of estrus and pregnancy rate of sows.

[0053] (3) Uterine development status: Sows were slaughtered on the 16th day of pregnancy, and 3 sows were randomly selected to measure the lengths of the uterine horns (left and right). Uterine samples were collected and fixed (4% paraformaldehyde), and HE staining was performed to compare the development status of the endometrium.

[0054] According to the above sample collection and detection methods, the improved group and the control group were collected and detected, and the results are shown in Table 3 and Figure 3 、 Figure 4 ; where Figure 3 The left side in refers to the average length of the left uterine horn obtained by detection, and the right side refers to the average length of the right uterine horn obtained by detection; Figure 4 In, A is the HE staining result of the improved group, B is the HE staining result of the control group, and the arrow symbol in the figure indicates the microvessels in the lamina propria; the triangular symbol indicates the endometrial glands.

[0055] Table 3 Uterine development of different timed insemination methods for replacement sows

[0056] Average left uterine horn length cm Average right uterine horn length cm Improved group 187.17 192 Control group 153.90 166.33

[0057] According to Figure 3 and Table 3, it can be seen that:

[0058] After the feeding days of altrenogest in the present invention are shortened from the conventional 18 days to 12 days, it has an obvious promoting effect on the length of the uterine horns of sows, providing more space for embryonic development.

[0059] According to Figure 4 it can be seen that: The microvessels in the lamina propria of the endometrium in the improved group are denser and richer than those in the control group, the abundance of glands in the lamina propria is increased, and they are distributed on both the basal side and the uterine cavity side. At the same time, the development of the glands is more developed, and more endometrial glands are linear or strip-shaped, providing a better environment for embryonic development.

[0060] The embodiments presented herein are only selected embodiments based on the combination of all possible embodiments. The appended claims should not be limited by the embodiments illustrating the present invention. Some numerical ranges used in the claims include sub-ranges within them, and variations within these ranges should also be covered by the appended claims.

Claims

1. A method for improving the effect of timed insemination of gilts, characterized in that: Select appropriate-age gilts and intramuscularly inject 900-1100 IU / head of PMSG. After 15-18 days, start the scheduled insemination program. The operation process of the scheduled insemination program is as follows: continuously feed 20 mg / head / day of allylprogesterone for 12 days, and intramuscularly inject 900-1100 IU / head of PMSG 42 hours after stopping feeding allylprogesterone, and intramuscularly inject 100 μg / head of GnRH 80 hours later, and perform the first artificial insemination 24 hours later, and the second artificial insemination 16 hours later.

2. The method for improving the timed insemination effect of gilts according to claim 1, characterized in that: Select appropriate-age gilts and give them an intramuscular injection of 1000 IU / head PMSG. After 15 days, start the scheduled insemination program. The operation process of the scheduled insemination program is as follows: continuously feed 20 mg / head / day of allylprogesterone for 12 days, and intramuscularly inject 1000 IU / head PMSG 42 hours after stopping feeding allylprogesterone, and intramuscularly inject 100 μg / head GnRH 80 hours later, and perform the first artificial insemination 24 hours later, and the second artificial insemination 16 hours later.

3. The method for improving the timed insemination effect of gilts according to claim 1, characterized in that: 10 ug of oxytocin was added to the semen used in the first artificial insemination and the second artificial insemination.

4. The method for improving the timed insemination effect of gilts according to claim 1, characterized in that: The suitable-age gilt is a gilt of 210±10 days of age.

5. The method for improving the timed insemination effect of gilts according to any one of claims 1 to 4, characterized in that: The suitable-age gilts are Duroc gilts.

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