Anatomical Structure Analysis Of Dairy Goat Cervix And Development Of Trancervical Artificial Insemination Gun

One of the most important factors that lead to the low conception rate of cervical orifice artificial insemination of diary goats is the cervix complex structure that hinders the sperm penetrated into the uterine body,usually only penetrated to the cervical orifice or shallow place in the cervix,leading to the loss of the semen,making conception rate declined obviously.In order to design a new artificial insemination gun of diary goats that can improve the penetration depth and then a better conception rate,this research firstly analyzed the cervical anatomy structure of 357 diary goats,and cervical silicone moulds was made by silica gel.According to the cervix anatomical structure of the diary goats and the cervical silicone moulds,the artificial insemination gun of diary goats was designed,and the experiment was carried out to verify the effectiveness of the new artificial insemination gun.The main results are as follows:(1)According to diary goats whether or not have the cervical folds the diary goat cervix can be divided into two types.The cervix that have folds accouted for 90.7%,the cervix that without folds accouted for 9.3%.In the cervix that have folds,the number of folds are 4.84±0.81,and with a length of 3.57+0.58 cm,1.64+0.25 cm in diameter.The length and the diameter In the cervix that without folds were 3.49+0.42 cm and 1.57+0.29 cm respectively.In the postmortem cervix penetration experiment with a conventional artificial insemination gun,the penetration rate were79.4% in cervices that have folds,and the cervix that without folds were 100%,the difference is significant(P>0.05).In the cervix that have folds,most of them are funnel-shaped pointed to the external cervical orifice,the lateral folds made many blind sacs,and due to the obstruction of the folds,the cervical canal becomes curved and narrow,resulting in the penetration barrier of the insemination gun.On the contray,The surface of the cervical canal that without folds is smooth and without obstacles,so the penetration of the insemination gun is easily.(2)The diary goat's cervix was solidified in formaldehyde,and then dissected at the central axle,we can see that there are many blind sacs in the cervical canal and the cervix are curved and extremely narrow.The model of the cervical internal canal of the diary goat was obtained by using the method of silicone perfusion,and the structure of the model were consistent with the anatomical structure.The model of the cervical folds of the diary goats that have folds were generally concentrated in the middle canal of the cervix.The model of the cervical canal that without folds is smooth and shows flat cylindrical simple structure.(3)in order to avoid cervical folds and achieve deep insemination,we developed four kinds of different structure insemination guns based on conventional insemination gun(No.one insemination gun)according to dairy goat cervical anatomy characteristic.No.two insemination gun: It have two same arc bends and a section of elbow.No.three insemination gun: It have two different arc bends and one elbow that its tip were in the central axis of the gun.No.four insemination gun: It has only one elbow at the tip of the gun.No.five insemination gun: It have five same arc bends and a section of elbow.Using five kinds of guns for artificial insemination,it was found that the penetration depth of the No.two insemination gun that with longer elbow was the deepest,which was 13.8+2.1 mm.But there were no significant differences between the each other groups(P>0.05).Meanwhile,there were also no significant differences between 5 groups at the pregnancy rate and lambing rate(P>0.05).In summary,the diary goat cervix can be divided into two types according to the cervix whether or not have folds.The clutter arrangement of the cervix having folds making the cervical canal curved and narrow,The surface of the cervical canal that without folds is smooth and without obstacles.Using four kinds of guns we developed for artificial insemination,it was found that the result of No.two insemination gun that with longer elbow was better.So we suggest use insemination gun that with longer elbow for diary goat AI.