livexlovexrodeo - 2018-03-29 11:34 AM Not to hijack your thread, but what about doing an embryo transfer in an older maiden mare? Is it kind of the same thing where you would just get a repro evaluation done? Since she wouldn’t actually carry a foal you wouldn’t have that risk so really if she still has normal heat cycles and everything is fine you could do it successfully? Just something I’ve always thought about.

casualdust07 - 2018-03-30 1:39 PM

Anything over 10 as far as repro concerned from a vet's standpoint is pushing old. It is what it is, and its not meant to hurt anyone's feelings. It doesn't mean the mare is OLD like anything derogatory, doesn't mean theyre infertile, just means things aren't going to be as ideal as with a mare under 10.


The main problem older maiden's have is failure of the cervix to relax. Normally, when a mare comes into heat her uterus gets edema and the cervix relaxes. In the repro world, we measure the cervix based on the amount of fingers we think can go through. a "1 finger cervix, 2 finger cervix, and 3 finger cervix." Or you measure them as A-C, A is open, B is in between, and C is closed. When a mare comes into heat, the cervix relaxes and fingers can easily be passed through, which means so can AI pipettes or a natural cover of semen. Older maiden mares for some reason *can* have this issue where even when in heat, the cervix remains tightly closed. We still breed them but what happens is it makes it easier or more susceptible for them to get infected because IF the mare has an infection, the cervix is closed and locks in all that fluid. Even if the mare is clean, post-breeding inflammation can occur and will worsen in the cases of mares with closed cervices. Fluid in, no way to get out, fluid pools, bacteria colonize--> infection--> unsuitable environment to maintain pregnancy--> no pregnancy at 15 day check.


In my opinion, you decrease your likelihood of getting a mare who keeps a cervix closed in heat in foal with live cover. With live cover, you can't guarantee anything made it through the cervix. Likewise, live cover IS dirtier than AI, because even when the penis is cleaned properly, there are still bits of smegma and debris that enter the vagina. If an older maiden has a cervix that has difficulty relaxing, you just put a high volume of fluid in that area, with no good way for it to get into the uterus and no good way for nasty stuff to exit the uterus in time for the pregnancy to drop down from the oviduct.


Is it the end of the world? No. Will it possibly be more of a challenge to get an older maiden in foal? Yes. Do we do it all the time? Yes. Is it always successful? No. Is anything always successful? No. Is live cover bad? No. Do I prefer AI? Yes.

casualdust07 - 2018-03-30 4:39 PM Anything over 10 as far as repro concerned from a vet's standpoint is pushing old. It is what it is, and its not meant to hurt anyone's feelings. It doesn't mean the mare is OLD like anything derogatory, doesn't mean theyre infertile, just means things aren't going to be as ideal as with a mare under 10. The main problem older maiden's have is failure of the cervix to relax. Normally, when a mare comes into heat her uterus gets edema and the cervix relaxes. In the repro world, we measure the cervix based on the amount of fingers we think can go through. a "1 finger cervix, 2 finger cervix, and 3 finger cervix." Or you measure them as A-C, A is open, B is in between, and C is closed. When a mare comes into heat, the cervix relaxes and fingers can easily be passed through, which means so can AI pipettes or a natural cover of semen. Older maiden mares for some reason *can* have this issue where even when in heat, the cervix remains tightly closed. We still breed them but what happens is it makes it easier or more susceptible for them to get infected because IF the mare has an infection, the cervix is closed and locks in all that fluid. Even if the mare is clean, post-breeding inflammation can occur and will worsen in the cases of mares with closed cervices. Fluid in, no way to get out, fluid pools, bacteria colonize--> infection--> unsuitable environment to maintain pregnancy--> no pregnancy at 15 day check. In my opinion, you decrease your likelihood of getting a mare who keeps a cervix closed in heat in foal with live cover. With live cover, you can't guarantee anything made it through the cervix. Likewise, live cover IS dirtier than AI, because even when the penis is cleaned properly, there are still bits of smegma and debris that enter the vagina. If an older maiden has a cervix that has difficulty relaxing, you just put a high volume of fluid in that area, with no good way for it to get into the uterus and no good way for nasty stuff to exit the uterus in time for the pregnancy to drop down from the oviduct. Is it the end of the world? No. Will it possibly be more of a challenge to get an older maiden in foal? Yes. Do we do it all the time? Yes. Is it always successful? No. Is anything always successful? No. Is live cover bad? No. Do I prefer AI? Yes.