Single Timed Insemination with Deslorelin

[Saffi]

I recently read a journal article about a trial in Brazil where they compared the pregnancy rate in mares given Deslorelin. The mares were split into 2 scanning groups. One group was scanned 6 hourly after Deslorelin and AI’ed with frozen semen after ovulation was detected and the second group was not re-scanned, only AI’ed 40hrs post Deslorelin. The pregnancy rate was slightly higher in the AI 40hrs post-dose group (70%) compared to the 6 hourly scan group.
The authors suggested AI’ing 40hrs post Deslorelin could allow more wide-spread use or frozen semen particularly in the field as opposed to clinic setting.

Whilst there is some variation in the literature about the “window” of ovulation that Deslorelin provides, some studies have shown that the majority of mares ovulate between 36 and 42 hours. Consequently if you did AI at 40 hours you would be with the window of ovulation and should have the semen at the oviduct within the lifespan of the oocyte.

So my question to Deslorelin users.
Have you ever kept records as to when your mares routinely ovulated after Deslorelin? Assuming the drug is given at an appropriate stage of cycle in a healthy mare. Would a single insemination at 40hrs have worked in your case/s?

Of course not scanning will bring a risk of being unable recognise follicular abnormalities so this is one drawback. But for cheaper semen or when one may split a dose I can see it being a useful method.

[Hillside_H_Ranch]

I’ve seen the study, and that is all well-and-good, but in practice I really prefer the 6-hour scanning, especially with a single dose. When you are talking about averages, yes, most mares do ovulate within a certain time-frame, but every season we have a handful of mares that DON’T respond to deslorelin and for me the numbers are high enough that I would never use a timed protocol without confirming ovulation. If you are the one client whose mare doesn’t respond, you don’t care if 90% of the other mares we bred DID respond; you are now out an entire breeding cycle and a dose of frozen semen and have to start all over. Perhaps for people who don’t have easy access to an ultrasound, or have their own stallion’s frozen semen, or (as you said) have a large amount of semen or cheap semen, but if it doesn’t work for you then you are still out a cycle and your time. I know many people do prefere the timed insemination (either with two doses or splitting a single dose), but I will stick with frequent ultrsounds and post-ov breedings as that has proven extremely successful for us.

[Kyzteke]

Do either of you have a link to the study? I like to see how many mares were involved.

Hillside, your husband is a vet, right? So I don’t blame you for preferring q6hr check. But after my last two years of hauling horses 2+hrs each way and using (a very qualified) vet for my frozen semen/ET adventures, I have to say that in most cases in the future, I will strongly consider just doing the AI at home with timed protocol.

Reason: well, in the last 2 yrs I’ve gotten ONE pregnancy from some 5-6 attempts. The one pregnancy was a mare AIed by me.

I started doing the math, and figured that if the frozen semen is below $600 per dose, I might as well buy 2 doses and (using 1-2 scans from my mobile vet) do the work here at home, using oxy inbetween.

Because I realized that, including gas, board, my time and the vet bill, I have NEVER walked o/o that vet’s office without at least a $500 bill per cycle.

I suppose if I was using super expensive semen, I would go back to the vet/scan q 6 hr. etc. plan, but as we all know, you can spend a ton with a vet and not get a pregnancy either.

Ask me how I know…

[Hillside_H_Ranch]

Yes, my husband is a vet, so of course I have my mares checked as often as needed. I was more referencing our client horses, however. For those clients that leave the mares with us for breeding we don’t even offer a timed insemination option. We will only do frozen breedings with frequent checks and post-ov insemination. I will also add that we don’t charge per ultrasound, but per cycle, so it isn’t like we do more ultrasounds to generate more $$$$. We just feel strongly that if owners are entrusting their mares to us then we will do everything possible to get them pregnant and for us, the post insemination breedings have been very successful. For people who prefer to do their own breedings, on their own farm, then certainly the timed protocols are a good option for them, and as I mentioned many people do have success with that.

I guess the main thing for me, personally, is that I don’t like to use 2 doses of semen when 1 works quite fine :)! And I will say that many of our clients are using some pretty pricey semen and I know they want to minimize doses, too.

Honestly, if I’d gotten only 1 pregnancy from 5 or 6 attempts, I’d probably be looking to do something different too; how frustrating!

[Home_Again_Farm]

I did timed insemination at home for a number of years when using reasonably priced semen from Celle stallions. It probably was a toss up financially for me - not really saving money over sending the mare to a clinic for frequent US and post ovulation insemination, but saving me the hassle and risk of sending a mare with foal at side off my farm.

I definitely agree with Hillside on this. Enough mares react unpredictably to deslorelin to make using it as described above distinctly unappealing. As Hillside said, if it is your mare that does not real the deslorelin playbook, it will hurt.

[Saffi]

The common protocol for using Deslorelin here is to give on a preovulatory follicle. So once this is established via ultrasound the mare is given the dose that evening. They are then re-checked at 24hrs but sometimes not, then the next scan is at approx 34/35hrs if all is going well and follicle still there and looking normal the mare is re-scanned a couple of hours later say around 38/39hrs. By this point in the 88/90% of mares that respond predictably they will have just ovulated or should be getting close. If things look funky you can just quit that cycle. Next scan would be at 40/41hrs and so on. But some get away with just a scan at 36 and 40. One prominent UK repro vet said to me that you can just about set your watch by Deslorelin because it works so well!

Hillside, do you guys time the administration of Deslorelin as above or do you check through the night? How often do you find that mares go well before or well over the predicted time? Are there reasons for this eg. Too early/late in cycle?

For breeders that do not have the luxury of a repro clinic with per cycle rates, I thought it was worth a try- provided of course you get the mare set up properly. Even if you could just reduce your scans to just a couple around the anticipated ovulation this may be more practical in an ambulatory setting.

I think the timed protocol whereby you use 2 doses of semen with inseminations at 24 and 40 hours is a little wasteful when you use Deslorelin. According to what I have read if you have the initial timing right then they are highly unlikely to go at 24hrs - if they did, that would put them in the 10% of abnormal responses and possibly that wasn’t a fertile ovulation.

Another study looking at the exact time to ovulation in mares given Des over subsequent cycles found that those mares ovulated at 39.7 and 39.9 hrs respectively (I might have those numbers back to front!). So I guess all this information from other studies actually adds weight to the first one I mentioned.

I think on another thread in the archives a user mentioned that their mares usually ovulate around the time of 39hr check - so in that case a blind AI at 40hr might have worked too!

I am not trying to take away the role of the vet in breeding but in circumstances where vet resources are limited and you would otherwise have to send your mare/s several hours to a facility then this may offer an alternative solution.

[Saffi]

Kyzteke, the research was published in a journal so not readily accessible to breeders. However, there was an article in the media about it late last year which I found after reading the original!

Anyway, I am considering trying out this theory as it would cost me more than a few doses of semen just to transport a couple of mares to a specialist clinic.

[Hillside_H_Ranch]

Once the mare has a dominant follicle of 30-35 AND adequate uterine edema (and edema really seems to be the key) then we give deslorelin. It is a little flexible and yes, generally the deslorelin is VERY predictable. In fact, for most mares, we try to give the deslorelin at a time where the breeding (this is all post ov for frozen) would take place during the day. In our situation we are almost always checking the frozen semen mares in the evenings, so if we found a dominant follicle with good edema we would delay giving the deslorelin for a few hours (depending upon exactly what time we checked them), so that ovulation and hence breeding would take place during the day However, if they have not ovulated by the anticipated time then we do keep checking them every 6 hours (often more frequently if they look close) and will breed at any time around the clock. I would have to pull the records from this year to find out how many DIDN’T work that way, but there were certainly some that I can remember clearly that did not ovulate in response to the deslorelin. It is very rare (for us) for the mares to ovulate earlier than expected, but not that uncommon for them to ovulate later than expected. I clearly remember one of my mares this year who did not ovulate in response to the deslorelin and we checked her for an extra two days, at which point we stopped (after another shot of deslorelin) because it was just too many palpations for her. On the next cycle she responded as expected and settled just fine. Why does this happen? Don’t know…because they’re mares I think the uterine edema is really important. If we have a mare with a dominant follicle (that we’ve been following, so we know she’s coming into heat instead of going out) that is 35, but no or very little edema then we won’t give the deslorelin. It doesn’t seem to work as well if there isn’t good uterine edema, so you can’t just depend upon the follicle size.

[Hillside_H_Ranch]

I wanted to point out, that in the 2-dose protocol, the 24 hour breeding is not intended for an ovulation that may occur at 24 hours. It is intended to cover an ovulation that might occur BEFORE the 40 hour point. That way the semen is in the mare, should she ovulate before the 40 hour breeding.

[Saffi]

Thanks for your response Hillside.
Yes I agree of course you need to have good edema and know where your mare is at in her cycle. I can tease my mares and know their cycle lengths well, I have good records of the follicle sizes at various points through their cycles from previous scans so all this information helps to make an educated decision as to when to scan to hopefully find a preovulatory follicle and give Deslorelin. Ie not much point scanning on day 1 of oestrus and expecting to find a good follicle, edema etc and away you go!

Re the double insemination, I am aware that it is not in anticipation of an ovulation at 24hrs (although this may happen with HCG). But with the longevity or lack of with frozen is this AI going to cover you until 36hrs? And if not many mares go before 36hrs then a single dose at 40 could cover you if the mare did ovulate at 36hrs?? Given the amount of mares that are supposed to ovulate within 48hrs (96%??) if the mare is still hanging on after that I would be starting to think about missing that cycle.

Hillside, in your case of the mare hanging onto the follicle - would you have expected that to have been a fertile ovulation in the end? Perhaps that was a case of the 10% that don’t read the book and even though the cycle was “wasted” is it possible that drugs or not it would not have been a successful cycle?

[Blume_Farm]

I am one of those mare owners whose mare did not read the data with deslorelin:(

I was attempting to use Hohenstein semen (bad idea) and so we used the deslorelin along with frequent palpations after giving it to really narrow down the time of insemination. First cycle she didn’t even respond to the deslorelin until after 48hrs so did not inseminate. This was in early March. Did a second cycle same way in late April and that time she did ovulate around 35hrs after administration. Great insemination time and still no Hohenstein foal:( Certainly not due to poor timing or infertile mare, just risky semen.

Just pointing out that some mares really don’t read the playbook. Like others said I might try it with well documented good frozen semen and on a mare well out of transitional heat months…but not with risky expensive semen and not too early in the season when heat cycles are less predictable.

[Hillside_H_Ranch]

The accepted time frame for a frozen semen insemination is 12 hours pre-ovulation through 6 hours post-ovulation. This is what the timed protocol is based on; so inseminate at 24 hours post ovulation induction drug, gets you to 36 hours, then breed again at 40 hours. Of course, some semen may live longer, or shorter, but that is the generally accepted time frame.

As far as cycles being fertile when the mare unexpectedly hangs onto the follicle; I have no reason to believe that those AREN’T fertile cycles. In the few cases where we’ve gone ahead and followed the mares for days, and then bred, they have usually gone on to get pregnant. We have had a few mares where it was a one shot try, no other opportunity, so if they don’t respond to the deslorelin then you just have to keep checking. I can clearly remember one mare who was here for an ET and there was only going to be one try because she had to leave for training. She did not respond to deslorelin and it was an additional 2 1/2 days of checking every 6 hours before she finally did ovulate. We did flush an embryo that resulted in a successful pregnancy. Luckily this type of scenario is the exception rather than the rule.

[Kyzteke]

You know, I was going to ask this question on EqRepro’s FB page, but I think I’ll ask it here as well:

I know the timed/2 dose protocol. That was designed when hcG was the ovulatory agent most used. I was told the earliest a mare would respond would be 36 hrs. Now with Des. it’s 40.

So why inseminate at 24? Why not 30? Even if the mare went alittle early you’d still be within the 6 hr. mark, which is a heck of alot better placement than 12 hrs. (we’re talking frozen here).

Why not make it hr. 30 & 42 or 45?

What am I missing here?

[Hillside_H_Ranch]

No, 36 hours and 40 hours aren’t the earliest, but the AVERAGE. In fact, the Sucromate label (deslorelin) says WITHIN 48 hours. The simple fact is that there are a significant enough number of mares who go earlier or later than expected that you just can’t say 40 hours is THE time. The two dose protocol is to cover the range of when mares are expected to ovulate when given HCG or deslorelin, which is 18-52 hours from being given the drug.

[Saffi]

For sure if the mare does not respond to the drug and holds onto the follicle but it develops within normal limits then you keep tracking it. I was thinking more of the exception where they grow and grow and grow and you get a HAF, LUF or they start to regress…chances are something like that would be infertile.

But yes I am curious about the twin inseminations surely you could in fact give it at say 30 and 40 hrs if you wanted to and maybe a dose at just 38hrs could work?

I am not saying you have to do it blindly but if you can get your vet to check a couple of times between 36 and 42 hrs then you can make an educated decision if the follicle is on track or not and whether the mare has responded or not. Or if you have enough semen in reserve you might be happy to take a chance.

I am not trying to argue with anyone but from the literature I have read there is a pretty good agreement that ~90% of mares will ovulate within 48hrs and ovulation will be induced in most mares by 40hrs, so for me there is not a statistically significant number of mares that don’t respond. Enough to be inconvenient but not enough to not use it for fear of being in the 10% group!

Looking back at a couple of the studies again…

The first one I mentioned actually had a lower pregnancy rate for the 6 hourly check group (<50%) vs ~70% for the 40hr AI with a stallion with good semen and something like ~40 and ~25% for a stallion with poor fertility. They used frozen semen they and 29 mares and repeated the experiment.

An older study from 2006 by Samper et al. where they wanted to work out the window of ovulation in HCG and ovuplant AI’ed all mares regardless of treatment at 36hrs. The pregnancy rate was about 70% for both treatment groups. If you look at the data you can pretty well guess which mares in the HCG group would not have taken as they ovulated at approximately 25hrs, 47hrs and one was 65hrs so possibly beyond the life expectancy of the semen. In this study they used chilled and frozen semen.

[siegi_b]

Saffi - there’s a world of difference between reading and studying it versus actually doing it… Just saying…

[Hillside_H_Ranch]

Saffi-
Please don’t get the impression that I’m trying to discourage you, or convince you NOT to do this on your own. You asked me some specific questions and all I can relate to you are my personal experiences. Certainly you can educate yourself and take whatever risk you are comfortable with. As you’ve said, it is different on the farm vs. in the clinic. We simply don’t take those types of risks with our client mares (or my own) because we want to maximize the chances of a pregnancy. I’ve never used the protocol you are interested in, so I can’t tell you how it would work. You just have to try it!

Also, 90% is too high, in regards to deslorelin. Here is the info straight from the Sucromate package insert (Sucromate is FDA approved deslorelin, there are compounded forms available). This is from an efficacy study with 10 mares treated and 10 mares given a placebo.

Treatment Group Ovulation by
48 hours
Placebo 0% (0/12)
SucroMate 1.0 mL 82% (9/11)

---

These are the numbers from a field based study of 94 mares given deslorelin and 97 mares given a placebo.
Treatment Group No. Cycles No. Mares Ovulated
by 48 hours
Placebo 131 97 27%
SucroMate 142 94 77%

Also please note in all of the research you quote it says induces ovulation WITHIN 48 hours, so some will also go much earlier.

I just wanted to clarify those points for others following this discussion!

[Kyzteke]

[QUOTE=Hillside H Ranch;7195904]
Saffi-
Please don’t get the impression that I’m trying to discourage you, or convince you NOT to do this on your own. You asked me some specific questions and all I can relate to you are my personal experiences. Certainly you can educate yourself and take whatever risk you are comfortable with. As you’ve said, it is different on the farm vs. in the clinic. We simply don’t take those types of risks with our client mares (or my own) because we want to maximize the chances of a pregnancy. I’ve never used the protocol you are interested in, so I can’t tell you how it would work. You just have to try it!

Also, 90% is too high, in regards to deslorelin. Here is the info straight from the Sucromate package insert (Sucromate is FDA approved deslorelin, there are compounded forms available). This is from an efficacy study with 10 mares treated and 10 mares given a placebo.

Treatment Group Ovulation by
48 hours
Placebo 0% (0/12)
SucroMate 1.0 mL 82% (9/11)

---

These are the numbers from a field based study of 94 mares given deslorelin and 97 mares given a placebo.
Treatment Group No. Cycles No. Mares Ovulated
by 48 hours
Placebo 131 97 27%
SucroMate 142 94 77%

Also please note in all of the research you quote it says induces ovulation WITHIN 48 hours, so some will also go much earlier.

I just wanted to clarify those points for others following this discussion![/QUOTE] What would be far more useful is know what % of mares went within 12 hrs. 24, etc. And have it done on a MUCH larger sample of mares…like a 100 or so.

I think we all know that if money is no object, we can have the vet do multiple checks. I also know that plenty of times mares don’t get pregnant when everything is perfect and the timing is great.

In fact, in my own personal experience (which is how we all tend to see things, admittedly)…I’ve had that happen more often than I’ve had a mare ovulate only 10 -12 hrs after getting an OA.

This year we gave one of my mares estrumate a counted 9 days after (confirmed) ovulation (as per a vet). He told me to bring her in Monday (this was Thursday).

Monday AM per ultrasound she was already at least several hours post ov…without having been given ANYTHING.

So mares can be goofy, we all know that. But it seems to me that if you play the odds, your timed protocol should be, farther out from the administration of the OA…because the odds are, she won’t ovulate that early.

But again, I am planning on using the timed protocol this spring, but tweak it abit so that the vet comes once a day to check. I will be using LFG frozen, so I can be alittle brave.

I’ll let you know how it works. Again, I spent almost $5k this year and got a big goose egg, doing it the right way…can’t be any worse than that…

[Blume_Farm]

Keep us posted! I wish you all the luck…and your right can’t be worse than last springs batting average for you.

[QUOTE=Kyzteke;7196086]
What would be far more useful is know what % of mares went within 12 hrs. 24, etc. And have it done on a MUCH larger sample of mares…like a 100 or so.

I think we all know that if money is no object, we can have the vet do multiple checks. I also know that plenty of times mares don’t get pregnant when everything is perfect and the timing is great.

In fact, in my own personal experience (which is how we all tend to see things, admittedly)…I’ve had that happen more often than I’ve had a mare ovulate only 10 -12 hrs after getting an OA.

This year we gave one of my mares estrumate a counted 9 days after (confirmed) ovulation (as per a vet). He told me to bring her in Monday (this was Thursday).

Monday AM per ultrasound she was already at least several hours post ov…without having been given ANYTHING.

So mares can be goofy, we all know that. But it seems to me that if you play the odds, your timed protocol should be, farther out from the administration of the OA…because the odds are, she won’t ovulate that early.

But again, I am planning on using the timed protocol this spring, but tweak it abit so that the vet comes once a day to check. I will be using LFG frozen, so I can be alittle brave.

I’ll let you know how it works. Again, I spent almost $5k this year and got a big goose egg, doing it the right way…can’t be any worse than that…[/QUOTE]

[Hillside_H_Ranch]

The field study was 90+ mares in each group, over several cycles per mare, so a total of 142 cycles total. That’s where the 77% came from.

I agree, it would be helpful to have it broken down further, time-wise.

Ultrasounding once daily should be extremely helpful in narrowing your window; good luck!