This is an archived Horseadvice.com Discussion. The parent article and menus are available on the navigation menu below:
HorseAdvice.com » Treatments and Medications for Horses » Reproductive Drugs » Human Chorionic Gonadotropin (HCG) »
  Discussion on Ovuplant/Hcg/post ov. insemination
Author Message

Posted on Tuesday, May 9, 2000 - 9:11 pm:

I took my maiden mare to the vet for AI via frozen semen. The vet gave Ovuplant, and 18 days later, no pregnancy! I've heard that lots of people are having problems w/Ovuplant, esp. with the mare not coming back into heat.
At 18 days (after the first try), my mare has a 45cm follicle. We're going to ultrasound in the am.
Anyone inseminate post-ovulation w/good results? The stallion's owner breeds her mares this way w/frozen and says she has good luck--and a vigilant vet.

Posted on Tuesday, May 9, 2000 - 11:34 pm:

I have never had a problem with Ovuplant. I love it. Has you mare not come back into heat? With a 45 mm follicle, it sounds as if she is cycling again, whether she is showing signs of heat or not. The ovuplant is a synthetic GnRH that causes an LH surge in the mare - thereby causeing ovulation. But the synthetic GnRH is very short lived in the bloodstream so I would look elsewhere for a reason that the mare stops cycling.

Frozen semen is hard to breed with. You must inseminate within hours of ovulation. I cannot imagine attempting to use frozen semen without the help of either HCG or an ovuplant because you have to time ovulation. Without it you would have to breed her every 4-6 hours, and that would get EXPENSIVE. During the freezing and thawing process, most of the sperm are damaged to some extent. It is very fragile by the time you put it in the mare so you want everything perfect.

As for breeding post-ovulation, yes it will work. But, and this is a big but, it has to be done within an hour or two after ovulation. According to everything that I have read.... the ovum will start to disintegrate between 12 - 24 hours after ovulation. The sperm must have 12 hours in the mare's reproductive tract to achieve capacitation - the final stage of maturation.

In practice though, ANYTHING can and will happen. I have bred a mare 24 hours after ovulation and had a pregnancy. I have also bred a mare 4 days before ovulation and had a pregnancy. These breedings were strange situations, and I got lucky with both. These are anomolies and I would not bank on them, and would laugh if someone told me they would work. There is a big difference between what can work and what will work!!

Posted on Wednesday, May 10, 2000 - 8:25 pm:

Hi Lyn. Mare is definately showing signs of heat. The follicle this am was still 45mm. We took her to the vet's and have all fingers and toes crossed! At 5:00 pm today, the vet said she was softening, and ultrasound showed a really good follicle. Just have to convince my mare to give it up!
She's a maiden mare, so using frozen is probably more chancy than a veteran, but.. couldn't get fresh and he's a really nice stallion!

Posted on Sunday, Jun 10, 2001 - 8:09 pm:

Dr. O,
What is the deal with Ovuplant anyway? My vet has administered to several of my mares for both artificial insemination (between inseminations), as well as to reduce the number of live covers I have to make during the busy breeding season. I've heard of several complaints with regards to Ovuplant - that it is not allowing the mares to come back into heat, and also that it must be removed. What's the scoop? I think this is the right thread to post the question, please forgive if I foibled!

Posted on Monday, Jun 11, 2001 - 9:42 am:

Well not exactly the right thread Susan. You are certainly in an approriate topic (Equine Medications and Nutriceuticals: Reproductive Drugs) but you have posted at the bottom of Liz's discussion, Ovuplant/Hcg/post ov. insemination without addressing Liz or the preceeding posters directly, Howeve since my post to Liz's question did not show up let me respond here (and there has been additional information has changed since May of 2000):

There is a excellent summary of a paper given at the 2000 AAEP meeting of this problem with Ovuplant. See Equine Reproduction: Breeding and Foaling: Heat (Estrus) Detection, Ovulation Prediction, and Timing Insemination to access it.
DrO
Home Page | Top of Page | Join Us!
Horseadvice.com is a BBB Accredited Business. Click for the BBB Business Review of this Horse Training in Stokesdale NC