JPH02191449A - Method and apparatus for transplantation of fertilized egg - Google Patents

Abstract

PURPOSE:To discharge fertilized eggs forcibly without carrying foreign matter in the genitral organs and to enhance a conception rate by inserting a straw having fertilized eggs received therein in the genital organs of an animal up to a predetermined position through the vagina and discharging the fertilized eggs in the straw by the pressure of air or a liquid. CONSTITUTION:An inner tube 2 formed of a metal or hard plastics is inserted in an outer tube 1 formed of a metal or hard plastics and a straw receiving tube 3 is connected to the leading end of the inner tube 2. A spherical surface- shaped tip 3a is mounted to the leading end of the receiving tube 3 and fertilized egg discharge ports 3b are provided to the lateral part of the tip 3a. The straw 4 received in the straw receiving tube 3 has fertilized eggs 5 received therein and the leading end thereof is connected to the fertilized egg discharge ports 3b and the rear end thereof is connected to a pressure feed tube. By applying the pressure from a pressure source 8 to the straw 4 through the pressure feed tube 6 by oppening the stopper 7 provided to the necessary place of the pressure source 8, the fertilized eggs 5 can be forcibly discharged in the genital organs from the discharge ports 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and an apparatus for transplanting a fertilized egg of an animal via a tube.

[Prior Art] In recent years, fertilized eggs have been transplanted for the purpose of actively propagating superior animal lines. That is, first, the sperm and egg of an animal of a superior strain are fertilized in the body or outside the body to obtain a fertilized egg. This fertilized egg is then transferred to another unrelated female. The transplanted female gives birth to offspring of superior species that are completely unrelated genetically to herself, resulting in the propagation of superior species through what is known as ``borrowing''. Let's explain this using the example of a cow.

The method involves transplanting fertilized eggs from Wagyu cattle (Japanese Black cattle), which have a high market price as beef, into dairy cows (Holstein, etc.) and causing the dairy cows to give birth to Wagyu calves.

The important thing in fertilized egg transplantation is how to improve the conception rate. At present, fertilized eggs are extremely expensive, so even if a fertilized egg is transplanted, it is economically very important whether or not the fertilized egg takes root in the reproductive tract of the recipient animal and develops, that is, fertilization takes place.

If the quality of the fertilized eggs to be implanted and the level of recipient animals are constant, the conception rate is determined by the method of fertilized egg implantation and the equipment used. In general, in order to improve the pregnancy rate, during transplantation, (1) avoid damaging the internal reproductive organs such as the uterus, cervix, and fallopian tubes and causing bleeding, and (2) prevent the internal organs from being contaminated with bacteria or external organs. (3) Ensure that the fertilized egg is expelled from the transplant device and delivered to the designated location in the reproductive organ.

(4) Since one hand is inserted into the rectum when transplanting, the transplant must be operated with one hand, so it must be easy to operate.

Considering the above-mentioned viewpoint, conventional transplantation methods and devices have the following drawbacks.

The one currently in use is the Casu type fertilized egg transplanter. As shown in Figure @3, a thin tube containing a fertilized egg 5, a so-called straw 4, is housed in an outer tube 1 made of plastic or stainless steel with a fertilized egg discharge hole 3b at the tip. . The straw 4 has an open end, and this opening is in close contact with the fertilized egg discharge hole 3b of the outer tube 1. The other sieve is closed with a cotton plug 11. A piston 10 is also inserted into the outer tube. When the tip of the outer tube 1 reaches a predetermined location in the animal's reproductive organ, the piston 10 pushes the cotton plug 11 that closes the straw 4, and the fertilized egg 5 is sent out from the discharge hole 3b and implanted. This method and implant have the following drawbacks. The place where the fertilized egg is discharged from the implanter is deep in the uterine horn P. However, since the uterine horn P is curved as shown in Figure 3-b, during transplantation, the uterine horn P is inserted through the rectum by the transplanter's hand, and the curved part is straightened and the fertilized egg is placed deep inside. is being emitted. This damages the animal's reproductive organs,
Examples include roughness, which causes bleeding and sometimes perforates organs, resulting in death of the animal. This is because the above-mentioned requirement (1) is not satisfied, and the discharge hole 3b of the fertilized egg 5 is opened parallel to the axial direction of the transplanter as shown in Fig. 3-a. When the tip passes through the cervical canal Q, the cervical mucus R closes the discharge hole, and even if the piston 10 is pushed at a predetermined location, the fertilized egg 5 cannot be discharged, and the requirement (2) cannot be satisfied.

In order to improve the above-mentioned drawbacks, a Casu type telescopic type transfer HD was recently devised. As shown in Figure 4, this consists of an outer tube 1, an inner tube 2, and a piston 1°.
A flexible straw storage tube 3 is connected to the tip of the straw. Further, the discharge hole 3b for the fertilized egg 5 attached to the tip of the straw storage tube 3 is perpendicular to the axial direction of the transplant device. A straw 4 containing a fertilized egg 5 and a flexible plunger 12 are housed in the straw storage tube 3. At the time of transplantation, the straw storage tube 3 is drawn into the outer tube 1, and when the transplant device passes through the cervical canal Q in Figure 3a, the inner tube 2 is drawn out from the outer tube 1, and the tip of the inner tube is pulled out. The flexible straw storage tube 3 attached to the tube is curved along the uterine horn P.

The tip can reach the desired location. At this time, since the straw storage tube 3 is flexible, it does not cause damage to the internal reproductive organs, so the requirement (1) is satisfied. *The discharge hole 3b for the fertilized egg 5 is perpendicular to the axial direction of the transplanter,
Moreover, since it is drawn into the outer tube 1 during transplantation, the discharge hole 3b will not be closed by cervical mucus R or the like.

However, the problem is that the Kasu type popular type transplanter mentioned above also has
In the Cassu type telescopic pink type, when expelling the fertilized egg from the straw into the internal genital organ, the recipient #I egg is inserted by inserting a piston into the straw through a cotton plug that closes one side of the straw. It is pushed out from the discharge hole. At this time,
Since foreign substances such as cotton waste coming out of the cotton plug are also sent into the reproductive organs, this does not satisfy the requirement (2) and is a cause of lowering the conception rate. In addition, since the fertilized eggs are pushed out by the piston, the movement of the volume in the straw is limited by the stroke of the piston (maximum the length of the straw).As a result, the fertilized eggs are not completely ejected and may not be near the ejection hole. This is because there is a high risk that the implant may remain in place and come out with it when the implant is removed from the animal's body cavity, or that it may migrate to other parts of the reproductive tract and be displaced from the optimal location for conception. ), and conventional transplanters have poor operability, making it difficult for the transplanter to perform the transplant alone and sometimes requiring an assistant.

Due to the combination of these factors, it has been difficult to increase the conception rate using conventional methods. For example, the average conception rate by transplanting bovine fertilized eggs is about 30%. In addition, the cost of transplantation was also high.

Furthermore, in recent years, there has been an increasing trend to transplant 251 fertilized eggs at the same time. -2 fertilized eggs at a time
If an individual is transplanted, the probability of conception increases, and if twins are born, productivity will also increase. Taking this as an example of a cow, if two fertilized eggs from a small-bodied Japanese Kuroge cow are transplanted into a large Holstein dairy cow, it is possible to produce twins, which would have been difficult for the welfare of the small Japanese Kuroge cow. Become.

To produce twins, two fertilized eggs must be implanted.

Conventionally, there are two methods for transplanting two cells.

First, ml is a method in which a transplant device is used twice and one transplant is performed one at a time. However, since this method involves inserting the implant into the animal's body cavity twice, there is twice the chance that foreign matter, including infection with 11 bacteria, will enter the genital tract from the outside. In addition, porting takes time and the work is complicated. The second method is to place two fertilized eggs in a straw in advance, and then discharge the two fertilized eggs by pushing a piston in two steps. However, with this method, as mentioned above, the volume movement is smaller than in the case of one egg, so the probability that the egg is completely ejected from the evacuation hole into the reproductive organ becomes even smaller. Furthermore, if the fertilized eggs are frozen stored eggs, one egg may have already died in the straw during storage and cannot be used. In this case, it will not be possible to transplant two rabbits at the same time, and the remaining healthy egg will be wasted.

In order to overcome this drawback, there is a method of transplanting using two straws containing one egg at the same time. but,
In the conventional method, the piston is inserted into the implanter with a narrow inner diameter.
1.It is technically difficult and difficult to install one. Also, for anatomical reasons, it is difficult to increase the outer diameter of the transfer device from the current one.

Taking the case of bovine fertilized egg transplantation as an example, the maximum outer diameter of the transplant device is about 4-5 mm. For the reasons mentioned above, it has been extremely difficult to improve the conception rate and produce twins using conventional methods.

[Problem B to be Solved by the Invention] An object of the present invention is to provide a fertilized egg transplantation method and an apparatus therefor that eliminate the above-mentioned conventional drawbacks. That is, it is an object of the present invention to provide a transplantation method and device that does not damage the reproductive organs of animals, does not introduce foreign substances into the reproductive organs, and increases the conception rate because the fertilized eggs are completely and vigorously expelled from the straw.

A second object of the present invention is to provide a method and apparatus for simultaneously implanting two fertilized eggs.

[Means for Solving the Problems] The present invention has the greatest drawback of the conventional methods. This method solves the disadvantages of foreign matter such as cotton lint entering the internal reproductive organs and the inability to reliably expel the fertilized eggs in the straw by using fluid pressure to deliver the fertilized eggs in the straw. In other words, the straw is inserted into the animal's internal genital tract via a straw containing a fertilized egg that is open at both ends.
In this method, the fertilized eggs inside the straw are discharged to the above-mentioned location along with the contents inside the straw using gas or liquid pressure.

[Function] The fertilized eggs are ejected from the straw not by using a piston through a cotton plug as in the past, but by using gas or body pressure, so foreign substances such as cotton waste do not enter. Since it is not restricted by the stroke of the piston and can easily move a volume tens of times the inner volume of the straw, the fertilized eggs in the straw can be forcefully and completely ejected out of the discharge hole. .

Furthermore, since a piston is no longer required, it is now possible to install two straws with the same outer diameter as a conventional transplant device without increasing the outer diameter of the transplant device. Therefore, 1
Two fertilized eggs can be reliably transplanted by inserting a transplanter. Of course, fertilized eggs are placed one by one in a straw, so even if frozen eggs are used, bad eggs can be removed in advance, so there is no waste like when two fertilized eggs are placed in one straw. The apparatus of the invention is illustrated in detail by the following examples which do not occur.

[Example] Example 1 In the fB1 diagram, reference numeral 1 denotes an outer tube made of metal or hard plastic, into which an inner tube 2 made of metal or hard plastic is inserted.

A straw storage tube 3 is connected to the tip of this inner tube.

The storage tube 3 is made of soft plastic, and a tip 3a having a spherical head is attached to the tip thereof.

A fertilized egg discharge hole 3b is provided on the side of this chip 3a. When the inner tube 2 is pushed, the straw storage tube 3 can be pushed out from the outer tube 1. When pushing out, it is of course possible to push the inner tube 2 by hand, but in order to satisfy the above requirement (4), a delivery mechanism is provided, and the pinch roller is rotated by the repulsive force of a spring or the action of a motor. It is also possible to automatically move the inner tube 2 held between the rollers. The extruded flexible straw storage tube 3 curves along the uterine horn P and reaches a predetermined location deep within the uterus.

The straw 4 contains a fertilized egg 5 and is housed inside the straw storage tube 3, and its tip is connected to the fertilized egg discharge hole 3b, and its rear end is connected to a pressure feeding tube 6. Reference numeral 7 denotes a stopper provided at a key point in the pressure supply pipe 6, and by opening and closing this stopper, pressure from the pressure source 8 is applied to the straw 4 through the pressure supply pipe 6, and the fertilized eggs 5 are released from the discharge hole 3b. Pressure sources that can forcefully discharge into the reproductive organs include plunger pumps, human exhalation, cylinders filled with compressed gas or liquid, and the like. Examples of media for transmitting pressure include air, inert gases such as carbon dioxide gas and nitrogen gas, and liquids such as distilled water, buffer solutions, and fertilized egg culture solutions. When using gas, it is desirable to provide a sterile filter 9 before reaching the straw 4. If liquids are used, it is desirable that they are sterile.

Example 2 fts2 Figure is an example of a transplanter for producing twins that is equipped with two sets of straw pressure supply pipes and stoppers. In this case, the pressure in the pressure pipe 6 is i! By the time they reach A8, they have merged into one. Further, one stopper 7 is attached to each of the two pressure pipes at key points. Instead of these stoppers, it is also possible to use a three-sided stopcock as shown in diagram m2-b.

Example 3 A fertilized egg from a Japanese black cow was transplanted into a Holstein dairy cow using the transplant device described in Example 1.

The outer diameter of the transplanter is 4.2 mm, and the length of the outer tube is approximately 50 mm.
cm. In addition, human exhalation was used as the pressure source. As fertilized eggs, fresh eggs were used for 8 animals and cryopreserved eggs were used for 10 animals. Transplantation was performed as follows. Contains a fertilized egg with an outer diameter of 1 mm and an inner diameter of 0. Cut one end of a straw of 7 mm and length 150 mm with scissors, then open the straw with an inner diameter of 0.8 mm and close one end with a stopper.
connected to the other end of the pressure pipe. The other end of this straw was again incised with scissors. The other end of this straw is closed by a stopper via the pressure pipe, so the straw
Attach the straw to the storage tube so that the opening of the straw is in contact with the fertilized egg discharge hole of the straw storage tube, so that the fertilized eggs inside will not flow out. The transplant device was assembled by connecting it to the inner tube that was placed in the tube. This transplant device was placed in a sheath made of sterilized polyethylene film, and the transplant device was inserted into the cow's throat. When the tip of the transplant device passes through the middle of the uterine intercondylar region, break the tip of the sheath, take the tip of the transplant device out of the sheath, push the inner tube first, take out the straw storage tube from the outer tube, and direct it toward the uterine horn. I proceeded. When the tip reached deep inside the uterus, the stopper was loosened and about 5 rnl of air was blown into the rear end of the pressure tube.

As a result of transplantation in this way, the conception rate was 55.5% (18
10 were pregnant during R.

Comparative Example Transplantation was carried out by the transplanter of Example 3 using a conventional transducer, a Cassu type telescopic type, and a Cassu type telescopic type.

At this time, the conception rate was 17.6% (3 out of 17) for the widespread type.
20% (3 pregnancies out of 15 ar!) were telescopic pink type.

Example 4 Using the transplant device for producing twins of Example 2, production of twins was attempted in the same manner as in Example fs3. A plunger pump equipped with a discharge valve was used as a pressure source, and a three-way switching stopcock was used instead of a stopper. Also,
Embryotic liquid, which is a culture solution for fertilized eggs (manufactured by Nippon Zenyaku Kogyo Co., Ltd., Koriyama City, Fukushima Prefecture), was used as a pressure transmission medium.
was used.

Each transplanter contains a straw containing one fertilized egg.
Two are installed. The straw storage tube of the transplanter inserted as in Example 3 is advanced deep into one uterus, and by switching the three-way stopcock, the plunger pump and one straw are connected, and the embryotic fluid is pumped for about 1 m. ], the fertilized egg is pumped by a plunger pump to the uterine horn 9i! Next, pull the inner tube into the outer tube, retract the straw storage tube to the bifurcation point of the uterine horn, extend the inner tube toward the uterine horn on the opposite side, and insert it into the opposite uterine horn. In the same way as before, remove the straw from the other straw.
Sent fill. At this time, the conception rate is 2OfX
Among them, 12 were pregnant, and 10 were twins. The conception rate was 60% and the twin rate was 83%.

[Effects of the Invention] As explained above, the present invention uses fluid pressure to expel the fertilized eggs from the straw, so the reproductive organs are not contaminated, and the fertilized eggs are completely expelled with great force, which improves the conception rate. is more than doubled by the conventional method. In addition, twin production can be achieved without wasting fertilized eggs or lowering the conception rate, which has great economic effects and greatly contributes to strengthening the competitiveness of the livestock industry.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of the fertilized egg transplanter of the present invention and a schematic diagram when it is inserted into the uterus, Fig. Wi2 is a new schematic diagram of the fertilized egg transplanter for twin production of the present invention, and Fig. 1 is a cross-sectional schematic diagram of a Cassu type popular type transfer device. And, it is a schematic diagram at the time of insertion into the uterus. Fig. 4 is a schematic cross-sectional view of a conventional telescopic telescopic type. ... Sterile filter 11 ... Cotton plug 13 ... Set screw P ... Uterine horn R ... Cervical mucus 2 - Inner tube 3a ... Titap 4 ... Straw 6 ... Pressure tube 8 -・・Pressure source 10・・Piston 12・・・Plunger Q ・・・Uterine tube cut・・・Cut mouth

Claims (10)

[Claims] (1) A fertilized egg characterized by inserting a straw containing a fertilized egg into a predetermined location in an animal's reproductive tract via a tube, and expelling the fertilized egg to the location using gas or liquid fluid pressure. How to transplant. (2) The method for transplanting a fertilized egg according to claim (1), wherein two straws are inserted at the same time. (3) The method for transplanting a fertilized egg according to claims (1) and (2), wherein the liquid is a culture solution for a fertilized egg. (4) An outer tube inserted into the tube, a soft straw storage tube inserted into the outer tube and having a fertilized egg evacuation hole at its tip, and a hard inner tube connected to the rear end of the straw storage tube. and a straw that is housed in the straw storage tube and has a fertilized egg inside, a pressure tube connected to the rear end of the straw, and a stopper provided at a key point of the pressure tube. A fertilized egg transplant device. (5) The fertilized egg transplantation device according to claim (4), characterized in that two sets of the straw, pressure tube, and stopper are provided side by side. (6) The fertilized egg transplantation device according to claim (4) or (5), characterized in that a pressure source is connected to the rear end of the pressure tube. (7) The fertilized egg transplantation device according to claim (6), wherein the pressure source is a plunger pump, a cylinder filled with human exhalation, or compressed gas. (8) The fertilized egg transplantation device according to claim (5), wherein the two pressure feeding pipes are merged into one pipe on the way to the pressure source. (9) The fertilized egg transplantation device according to claim (4), (5), or (6), further comprising a mechanism for feeding out the inner tube. (10) The fertilized egg transplantation device according to claim (9), wherein the feeding mechanism is a pinch roller.