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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