Sharon Terry Box 1178 State College, Mississippi
ARTIFICIAL INSEMINATION OF HORSES by Sharon Terry
EDITOR’ S NOTE: Sharon Terry is currently studying Pre-Vet at Mississippi State University and is well qualified to write on this subject of vital importance to the horse business. We appreciate Sharon’ s efforts on our behalf and are sure our readers will benefit from her article.
Artificial insemination is a method of breeding that has been " cussed and discussed” a great deal the last several years. Artificial insemination can be very useful to the stud manager on days when there are seven or eight mares to be bred. Using artificial insemination the stallion can be used only twice— yet all the mares can be served from these two ejaculates. This method allows for all of the mares to be bred at the right time and it is done in such a way as to prevent overworking the stallion. The equipment necessary is relatively simple. An artificial vagina can be made or purchased. If it is made some sort of rubber tubing should be used. The A. V. should be 18 inches long and 7 inches flat
in diameter. It should have an outer and an inner
tube so that it will hold the water necessary to create the pressure. One end narrows to fit over the 8 to
10-ounce collection bottle and the other end is left open for the stallion to enter. The internal temperature of the A. V. should be 113 ° F. To accomplish this the water may be heated slightly above this temperature when it is put into the A. V. The A. V. should have a valve where some of the water may be let out if the pressure becomes too great.
In collecting the semen the stallion and mare should be treated as if for natural service. A mare in heat should be used as a teaser. The mare should be hobbled and twitched if necessary. Two assistants are required to handle the A. V. The stallion is allowed to mount the mare and the first attendant grasps e sheath and directs the stud into the A. V. The second attendant holds the A. V. at an upward angle beside the mare’ s flank. Ejaculation time on the stallion is approximately 8-10 seconds and the total ejaculate
May, 1968 will range from 75-200 cc’ s. The assistant closest to the stallion can feel the stallion ejaculate and as he does so the A. V. may be tilted downward for the
ejaculate to flow into the collection vial. The A. V. is then removed and the stallion left to dismount the mare.
It is always a good idea to keep a fertility check on breeding stallions. A slide should be prepared periodically to check the concentration and motility of the stallion semen. The concentration is stallion semen is 100 million sperm per cc. A certain number of abnormal sperm( 5-10 %) is commonly found in every ejaculate. The Progressive Motility test can be run to determine the motility of the sperm. A slide can be prepared as it comes from the stallion or a diluter may be used to further enable the operator to determine the concentration. If the diluter is used a suitable one would be a sodium citrate buffer( 2.9 grams sodium citrate dihydrate buffered solution using 50-80 % buffered solution and 20-50 % fresh egg yolk). The dilution rate is 1 part semen per 25 parts diluter. A small drop of the semen or diluted semen should be
taken and placed on a slide with a cover slip over it. Under 440 magnification a good estimate of motile
sperm can be obtained by observing the number of sperm moving ahead. Knowing the motility and concentration enables the operator to know whether to use more semen per dose than standard.
Stallion semen does not need diluting to breed the mare. The ejaculate should be used as soon as possible after collection and a 20 cc dose per mare should be a sufficient dose per service. The mare should be restrained as for natural service to be inseminated. Insemination may be done either by a catheter or a capsule. Generally speaking, the catheter is the simplest method to use. A rubber hose such as a worming hose is suitable and probably easier to manage. The hose or catheter should be placed through the cervix so that the semen is deposited just through the cervix into the uterus. A syringe
may be used on the end of the hose or catheter to propel the semen.
The heat period of a mare varies from three to eight days with an average of five. It is best to inseminate at least twice and, if possible, to try to catch the mare on the next to the last day for ovulation occurs 24 hours prior to the end of estrous. The mare has a 21-day estrous cycle.
Needless to say, accurate breeding records should be kept on services and heat periods as in any breeding operation. Efficiency and management play a tremendous part in a successful breeding program.
Artificial breeding will most probably play a great
role in the future because of its accuracy and benefits. Until just recently it was primarily used in cattle but in the last few years quite a few horsemen have begun to use it. As stated earlier, its greatest asset is the fact that it enables many mares to be bred
with little hardship on the stallion, and this is the point that is making it so popular with the larger breeding operations. * 1 2 3
1 Year. 2 Years 3 Years
VOICE SUBSCRIPTION RATES
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