Enchcing Sheep Breeding And Rapid Propagation Using Laparoscopic Technique

For decades, the technology of the animal in vitro fertilization, estrus synchronization, superovulation and embryo transfer is an effective means of modern livestock breeding, which has been used widely in the process of livestock production and livestock improvement. Among them, the IVF technology has made a series of achievements in the applications of purebred sheep breeding and rapid propagation. However, the fertilization rate and pregnancy rate are still the single most important factor affecting the process of sheep embryo transplantation industrialization. Laparoscopic techniques have features of less trauma, less bleeding, tissues and organs damage, no adhesions, short wound healing period, fewer complications in clinical surgery, and etc. So it has been widespread attention in the field of livestock breeding both at home and abroad. the ultimate goal of the use of laparoscopic techniques to operate sheep embryo transfer is to improve the speed of fine breeding sheep, to provide means for the fast expanding group of large-scale farms, to create opportunity for the efficient use of sexual control semen and frozen semen, to improve cost savings for farmers and bring considerable economic benefits, and to show the double roles in scientific research and production applications. Thus, we will be able to take advantage of these advanced science and technology to speed up the speed of our industrial development of the embryo transfer speed, to improve and enhance our standard of domestic embryo transfer technology,to enhance the competitiveness of international trade in embryo.To further improve the sheep in vitro fertilization and embryo transfer efficiency rate, the present study adopted the laparoscopic techniques to sheep in vitro fertilization and embryo transfer, according to the location, the sperm density and the time of insemination to determine are the best sheep insemination and embryo transfer method. In second half of 2015, it is on the proving ground for the relevant tests about sheep Suffolk in ShenmuYulinShaanxiProvince, erlintu farmer cooperatives.Experiment 1: the comparison of different parts of insemination. After super ovulation to the donor Suffolk sheep, adopting respectively the traditional Cervix insemination, laparoscopic uterine horn insemination and laparoscopic tubal uterine horn insemination, in order to find out the ideal site of Suffolk sheep insemination with the laparoscopic techniques. The results showed that the use of the uterine horn and fallopian tube obtained fertilization rate of viable embryos is eligible respectively 94.1% and 89.0%(P <0.05), while the cervix group recovered to 84.7% of the available odds, the difference between the other two groups significantly(P <0.05). Because of in the comparison to between uterine horn structure and the fallopian tubes, uterine horn structure with advantages of feasible stretch, easy bleeding, low adhesion, easy to operate in the insemination process, so we adopted the laparoscopic uterine horn insemination method in the testing process.Experiment 2: the comparison of effective sperm density. We adopted the Laparoscopic uterine horn insemination techniques to fertilize different densities sperm insemination in order to explore the lowest effective sperm density when Suffolk sheep were intrauterine insemination,. Tests were designed five groups of effective density respectively 2 × 108 cells/ml, 3 × 108 cells/ml, 4 × 108 cells / ml, 5 × 108 cells / ml, 6 × 108 cells / ml, and found that the group of 2× 108 cells / ml was eligible for the lowest rate of viable embryos,73.9%, significantly lower than other groups(P <0.05); while the other four groups obtained available embryo rate without significant difference(P> 0.05). So choose 3 × 108 cells / ml density in practice carried out insemination, it was possible to ensure the embryos effect, at the same time, avoid unnecessary waste of semen, and shown the efficiency between frozen semen and sexed semenExperiment 3: the idealtime of the insemination time. Ewe ovulation time was generally at the end of estrus 3 to 4 hours, by using of laparoscopic techniques to test sheep laparoscopic uterine horn insemination after the withdrawal ties of 48 h, 54 h and 60 h.it was desirable to obtain relatively appropriate Suffolk sheep insemination time. It was found that the group of 54 h is eligible for the highest rate of viable embryos, 89.5%, significantly higher than the 60 h group 84.4%(P <0.05), in addition, there were little difference between the group of 48 h with available embryos of 88.7% and 54 h group(P> 0.05), the results of the test could provide a reference for the sheep production process and did favor in exerting potential of the donor sheep breeding.Experiment 4:adopting respectively traditional surgical transplantation and laparoscopic techniques transplantation to embryo transfer in sheep to compare two surgical methods of embryo transfer efficiency. It was found that the rate of sheep pregnancy and lambing in the group of adopting laparoscopic insemination is respectively 76.04% and 131.9%. There is significant difference between 70.8% and 119.4%(P< 0.05) of the traditional surgical method group in the experimental. At the same time, compared with the traditional method in the operation with advantages of a small wound, less bleeding, low adhesion and other characteristics, so laparoscopic embryo technology could be applied to the sheep transfer work in the production process.We groped the methods of appropriate insemination site, ideal insemination time using the laparoscopic techniques in the process of sheep insemination and embryo transfer. These methods with the advantages of low-dose, high precision and high efficiency of reproductive can greatly improve the excellent semen, especially the efficiency of sexed semen, and reduce kinds of investment resources, improve reproductive efficiency. The results will lay a solid foundation for accelerating the industrialization of breeding sheep and scale of the developing process.