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Penniless
02-06-08, 03:14 PM
Wonder what the odds would be. Just had our final mare confirmed in foal this afternoon and yet again pregmant but twins! This now means that every one of our mares except one have all got pregnant on their first covering and have all conceived twins. Thankfully the others who were confirmed in foal months ago are still pregnant with the one remaining one, so hope this mare holds on to hers too. Suppose this means that we'd better start thinking about advertising the foal she's got on her now before the full sibling arrives next year. Apart from our own stallion, we've also used two outside stallions so our vet reckons we must have extremely fertile mares.

AndyPandy
02-06-08, 03:46 PM
I think twin pregnancies currently represent about 7% of all diagnosed pregnancies... so (statisticians, please correct me if I'm wrong), the chance of you getting twins with 5 mares (not sure how many you've got) would be 0.00017%, if they were randomly selected mares.

However, twinning is far more prevalent in certain breeds, and with certain breeding. Do the mares share similar bloodlines? Use of PG also increases the chance of twinning along with a few other things.

It's interesting though... they'd obviously be good embryo transfer donors (if you're ever allowed to go down that route http://www.horseandhound.co.uk/forums/images/graemlins/smile.gif)

Ciss
02-06-08, 04:44 PM
I have also heard that once a mare has twinned once she is more likely to twin again, especially as she gets older. I have to say that when I was breeding that certainly did seem to be the pattern with my mares.

Any comments AP?

AndyPandy
02-06-08, 04:52 PM
Older barren mares are most likely to produce twins regularly - the theory is that it's the last chance for these mares, so nature is desperately trying to produce a pregnancy!

Once they've twinned once, yes they tend to twin again. Regular double or triple ovulations certainly have a genetic basis, and I'd expect that the genes responsible for it aren't fully switched on until the mare reaches full sexual maturity at the earliest, or that they're part of the "we must get a pregnancy" mechanism of older mares.

So, for your mares Ciss, that would make sense. But also for Penniless's mares... from now on, check them very carefully for twins EVERY single time http://www.horseandhound.co.uk/forums/images/graemlins/laugh.gif

ASTJMHR
02-06-08, 06:03 PM
Absolutely. Case in point is our own mare - 6-8 years single pregnancies, 8-14 years consistent twinning, 14 years plus tripleting. 3 Grafenstolz babies last year would have been terrific! Her mother followed a similar pattern and her daughter will be ET'd next year - we're hoping she will follow suit, only from a much earlier age!

Penniless
02-06-08, 10:11 PM
[ QUOTE ]
I think twin pregnancies currently represent about 7% of all diagnosed pregnancies... so (statisticians, please correct me if I'm wrong), the chance of you getting twins with 5 mares (not sure how many you've got) would be 0.00017%, if they were randomly selected mares.

However, twinning is far more prevalent in certain breeds, and with certain breeding. Do the mares share similar bloodlines? Use of PG also increases the chance of twinning along with a few other things.

It's interesting though... they'd obviously be good embryo transfer donors (if you're ever allowed to go down that route http://www.horseandhound.co.uk/forums/images/graemlins/smile.gif)

[/ QUOTE ]

Nice to know our mares are in the minority then! No, none of them share the same bloodline at all - all TB mares with totally different bloodlines (unless of course you go back about 10 generations). Some of them were maiden mares last year and were 6 and 7 year olds and the older mares were 16 plus and had produced between 5 and 7 foals beforehand (including one being a granny). None of the mares were given PG at all - they were all kept under lights from September last year and the first mare was covered on February 16th and confirmed in foal 15 days later. Because of the twinning factor, none of our mares are scanned any later than 15 days. Embryo transfer naturally is a big no for us at the present time as they are all destined for the racetrack and unless covered by natural covering with no artificial help (i.e. AI or embryo transfer), we wouldnt be able to get a covering certificate nor register them which means no race them. We also have Darley owning half shares in some of the foals and don't think they would be very happy if our top broodmares suddenly produced a dozen or so foals in one year! So if anyone wants to do a paper on twinning, you know where to come. As we've said, this isn't unique this year, one of our mares for the past 6 foals has twinned, and one for the past three years has as well. As for us, we'd love one year to take a gamble and tell our vet to leave 2 inside one of the mares but would never do it, in case it risked both the health of mum and the foals.

cruiseline
03-06-08, 05:37 AM
I have one particular mare, ISH who has always twinned. We have bred her 5 times now and everytime a twin pregnancy.