what’s your personal opinion on how old a mare can be to have her very first foal? Is 20 too old? 15? 10?
In the last couple of years we successfully bred two 13yo maidens with a single dose of frozen semen each. One foaled a lovely colt for us, proved to be an absolutely phenomenal mother, and got back in foal on another single dose of frozen on her foal heat; the other is due to foal in another month or so.
Depending on the mare, of course, I think mid to late teens would be about the age that I started to hesitate, though I have known a handful of mares who were first time mothers at 17/18 with no problems.
bump–Ive just been offered an older maiden would be very interested in thoughts/experiences.
I bred a 14 y.o. maiden two years ago with fresh semen. She required management of the cycle, both pre and post breeding because she had a very tight cervix, but she got in foal with one insemination.
One of my students bred her 19 year old maiden TB mare :eek: to A Fine Romance, she took on the first insemination with fresh cooled.
Of course this student is one of these rare people who seems to somehow “control the universe”; she did this kind of on whim, and just hoped for the best (taking my suggestion as to the sire, since she wanted to breed to a sporthorse TB, her goal being to event the foal, her mare was competing successfully at Novice but struggled with the scope required for Training–however, she was LOVELY to look at, and had great conformation, movement, and temperament.) The mare went right to 340 days, the resulting filly will be 7 this April. No issues whatsoever with getting her in foal or keeping her in foal (my lucky student!!!) but this is apparently a real rarity with much older maidens!
My own maiden mare (who was 13 when bred) was tougher; she had a tight cervix, built a LOT of fluid, and didn’t take after the first (two) inseminations, even though she was carefully managed by one of the best repro centers on the East Coast, ERC, where I left her. It WAS, however, one of the hottest summers on record when I had her bred, which may have factored into her either not conceiving, or possibly losing the conceptus.
She was not “teasable” (Alpha mare :rolleyes:), so they basically had to hand-manage her cycle, using frequent U/S to check on her progress. She was both slow to build a follicle and slow to ovulate, they had to use HCG and time it to when she showed a “breedable follicle”, and arrange to get the semen shipped from CA overnight. Twice, actually, three times (we are in VA.) Thank GOD for a fantastic stallion owner!! Hats off to Edgar 
Anyway, post breeding she had to be flushed and given oxytocin, and even THEN they were not optimistic! She built a good deal of fluid (due to the inflammatory response and the tight cervix), so all we could do was cross fingers and wait, since it was late in the year at this point, and I only had the money for one more try. (I left her at the Repro center both times, it was expensive, but WELL worth it in retrospect.) The second time around, we had a glorious black dot, resulting in tears and hugs, all around. Talk about putting all of one’s eggs in one basket! So to speak. This was my performance/competition mare, and getting a foal out of her was my dream.
I now have a beautiful filly, born at 325 days gestation (after my mare developed placentitis at day 260, which was ANOTHER story), so it was ALL worth it…My precious girl will be 3 at the end of June 
It IS possible, but be prepared to A) spend more than you might anticipate spending, and B) get the BEST repro team you can find.
Good luck! BTW, how old is the mare in question?
I think 20 is definitely too old for a mare to have her first foal. 10 is fine, and you’re pushing your luck at 15.
Other considerations concern whether you use frozen or fresh-cooled semen. I also find that as mares get older they have a tendency to have better success rates with fresh-cooled. Another very important factor in my opinion is the attending vet… Make sure (s)he doesn’t just do the occasional breeding, but spends the majority of her/his time getting mares pregnant.
Good luck!
We bred a 16 year old maiden TB mare with fresh with no problems. Caught first time. The only difference was that the foal was born after 12 months gestation. A little small at birth but totally healthy. Finished at 16.1 and had a great A hunter career. Still with us at 26 years of age and looks great. If the mare is healthy I would not worry to breed a maiden up to about 20 years of age. After that I would feel the mare does not really need to have to deal with a baby at 21!
