HCG, GnRH, and Ovuplant
HCG, GnRH, Ovuplant
Hormones used to Controll Ovulation
HCG, GnRH, and Ovuplant are all hormones for controlling ovulation in the mare. They work by either acting directly on the follicle or by stimulating the brain to release hormones that work directly on the follicle. The end result is the release of the egg from the follicle, known as ovulation, within forty-eight hours of administration.
The importance of using these hormones is to predict when ovulation will occur. Once this has been determined, semen can be ordered or a visit to the breeding shed can be scheduled.
When breeding is with the use of fresh cooled semen, the request for semen must be made the day before it is needed. In some areas same day delivery is an option, but not here deep in the Ozarks. By observing the ovaries and uterus for signs of progressive heat and then using the above products, semen can be ordered with confidence that ovulation will occur shortly after insemination. This saves the expense and time of numerous palpations and ultrasounds monitoring the progress of the dominant follicle to the point it would naturally ovulate. Inducing ovulation also assures semen will be needed during the week, eliminating the need for shipping over a weekend when rates are higher if shipping is possible at all.
With the use of frozen semen, the HCG products have a very important role. Due to the importance of insemination within 6 hours before and within 6 hours after ovulation, it is very helpful to know when ovulation is likely. By administering one of the HCG products, the palpations and ultrasounds can be concentrated within a twenty four hour period. Again, this saves the expense and time of numerous examinations monitoring the progress of the dominant follicle.
In embryo transfer, the HCG products are used extensively. Initially, of course, they are administered to the donor mare to schedule insemination. They are also administered to the recipients to synchronise their ovulation's with that of the donor. The recipients are programmed to show signs of heat shortly after the donor, but due to the tendency of each individual to cycle on her own schedule, they may not progress at the same rate. In addition, the donor is induced to ovulate to more efficiently make use of shipped semen. This puts her ovulation a day or more ahead of the synchronized recipient's natural ovulation.
We hope this brief description of the use of the HCG products helps explain the importance of its use in your mare.
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