With the increasing dependence on reproductive techniques that require well timed ovulation, there has been a steady push for systems and drugs to control cycling and the time of ovulation. Artificial insemination, embryo transfer, and minimal contamination techniques for subfertile mares are all examples of techniques that benefit from a predictable time of ovulation. Even for natural service of healthy mares, a well timed ovulation will decrease the number of covers allowing for more mares to be bred to a stallion.

The hormone that naturally causes maturation and ovulation of the follicle is luteinizing hormone (LH). It is released from the pituitary gland in response to increasing levels of gonadotropin releasing hormone (GRH) where it circulates to the growing follicle and stimulating maturation and ovulation. Currently there are two commercial products available that hasten ovulation of a maturing follicle:

• Human chorionic gonadotrophin (HCG) which has LH properties, ...more.
• Deslorelin has GRH properties which stimulate natural LH. Deslorelin is manufactured by Fort Dodge and marketed under the name Ovuplant®.

This article discusses the actions of desorelin (Ovulplant®), its use, pharmokinetics, side effects, drugs interactions, and dosage. For specific breeding programs to time insemination see Equine Reproduction » Breeding and Foaling » Heat (Estrus) Detection, Ovulation Prediction, and Timing Insemination.

Ovuplant (deslorelin) is a synthetic GnRH analog in a biocompatible sustained release subcutaneous implant with the indication to induce ovulation in the estrous mare within 48 hours. Ovuplant is formulated as a cylindrical implant in a preloaded syringe with an attached needle (implanter).