Zenyatta

Queen of Racing

Ask The Experts

Ask The Experts #7

Q:

I am curious about the length of time a horse will breed. Will Z have a foal every year, or does she take time off? What is the average age to retire a broodmare?

Gail Clark

Laramie, WY

Zenyatta is currently in foal to Tapit. Photo by Alys Emson

A:Thoroughbred mares are usually are not bred before their three-year-old year, and they frequently have foals when they are 21 or 22 years old. The gestation period is about 338 days, plus or minus three or four days.

Mares will usually come into estrous (heat) seven to ten days after foaling. We rarely breed mares during this heat because it does not allow a mare adequate recovery time after foaling, has a low percentage of conception and a slightly higher incidence of fetal loss.

Some mares adapt to motherhood very well and seem to thrive on it, while others do not handle it as well. If everything goes normally a mare will probably be bred on her second estrous cycle after foaling. This occurs at around 27 to 30 days post foaling. There is a high percentage of conception at this cycle and low incidence of fetal loss.

Since the mares’ gestation is more than eleven months, and we don’t breed until 30 days after foaling, they tend to foal a little later each year. Consequently it is difficult for a mare to have a foal every year. Usually, if everything goes normally a mare will have four or five foals and then take, or have, a year off. Occasionally a mare will foal 12 or 13 years in a row, but that is unusual. These mares seem to flourish in a pregnant state.

Mares are weaned at around five to six months after foaling, turned out most of the time weather permitting, and are usually brought in every night about a month before their due date.

Our Expert

Richard D. Holder, DVM

Hagyard Equine Medical Institute

Dr. Holder completed his Doctor of Veterinary Medicine at Texas A&M University in 1972. Immediately following, he joined Hagyard Equine Medical Institute as an intern. He has then stayed on with the clinic as a Field Care Associate and then as a Member of the practice. He specializes in Theriogenology, and developed fetal sex determination techniques from 5-150 days.

Reader Interactions

194 Comments

  1. / Reply

    Wow. That’s a lot of complicated stuff! Zenny seems to be one of the mares who thrives in every situation. She is great at everything she does!

    • / Reply

      Oh yes Pati,

      Thanks so much to Dr. Richard Holder for giving us the “low down” on TB breeding
      practices. And THE QUEEN she does look wonderful, racing, in foal, with a foal by her side. She just love living the life of an Equine and is a very special mare.

      GREAT INFORMATION LANES END AND THE MOSSES, SO GLAD TO KEEP UP TO DATE.

  3. / Reply

    Thanks for the information! So many people were unhappy when they found out that Zenyatta was bred two years in a row. Hopefully everyone will realize that this is actually normal and healthy. :)

  4. / Reply

    Wow, another post!!! Wooohooo!!! Thanks for the question, it was a good one and we were given a very good answer.

  5. / Reply

    Another thing to consider is Mother Nature. If Z’s body couldn’t handle a pregnancy she’d lose the pregnancy. Mother Nature is very clear about this.

    When I was a kid the rule was for every four years a mare is bred you can expect three babies. I’m sure there exceptions to this (as stated above)but once every three/four years a mare no matter how you try she can’t seem to get into foal.

    La Ville Rouge is a great example of this.

    • / Reply

      Zenny’s dam Vertigineux is another. She had a foal in 2002, 2003, & 2004, then no foal in 2005, had foals in 2006 and 2007, no foal for 2008, had foals in 2009, 2010, 2011, no foal for 2012 and hopefully she will be having a FULL sibling to Zenyatta for 2013. Nature knows when it’s time for a break or they will just get to late in the season to try and will just wait until next year.

        • There’s an old saying about breeding and trying to replicate a sibling, like Zenyatta: “Mrs. Sullivan had 8 sons….and only one John L.!” The same parents can have wide diversity among their kids — it’s a part of pedigree analysis and genetics that is fascinating to me, and I have about a thimble-full of knowledge in this area. Fun to read up on and study, though. I’m getting anxious and excited about the prospect of seeing Eblouissante make her debut, hopefully soon! When John says “she’s ready!” Looks like her timetable will be similar to Zenyatta’s.

        • Yes I agree you don’t always get what you set out to create. We can just believe for the best.
          I am also anxious but excited about E she will be great. very soon :)

        • SO VERY TRUE, BUT 12 Z DOES CARRY HER GENES AND THAT IS
          GOING TO BE SOMETHING IN THE BREEDING SHED.

  6. / Reply

    Really great question Gail. I’ve often wondered the same thing, so thanks for asking!
    And thanks for the great answer Dr. Holder! Queen Z looks beautiful and I’m so glad to hear she’s a great mom; as if she could be any other way :)

  7. / Reply

    I like this post. I know that Zenyatta has a lot of fans that aren’t necessarily well informed about horse breeding/health. People were really getting bent out of shape about it on different blogs. Good post.

      • / Reply

        I have a feeling that the least informed tend to fall back on what they DO know, which in many cases might just be anthropomorphizing a bit too much (“oh gosh, if it were me I would HATE to give birth and then have to be pregnant again so soon every year”). Rest assured, Z fans; the Moss’ obviously care a great deal about their horses, Z included, and have been in the horse business for some time. If breeding her every year was in any way out of the ordinary, it would be on plenty of news sites and you’d be hearing a lot more about it. Z has the best vet care she could get, so I’m sure if there is ever any doubt that she can handle a pregnancy one year, they won’t breed her.

        • People also forget that horses don’t keep the kids around for 18 yrs +. But you are exactly right

        • @signofthetimes … I know? That’s actually part of my point? /I/ understand that, but like I said, I think it’s the most vocal/least informed that Kathleen mentioned that don’t get that (like I said, I think they anthropomorphize a bit too much if they don’t understand horses/horse racing/breeding). :)

  8. / Reply

    Zenny is wonderful at every thing she does!!
    It is far easier to keep a mare in foal every year than it is to give them ‘time off’ and then try to breed them again. That is especially true as they get older. I had a mare that foaled out a filly when she was 22. We rebred her, but she didn’t take, and Pippy turned out to be her last baby. I gave her to one of my riding students, who also bought a weanling filly from a different mare. The filly was 5 months old, and Amira actually produced milk for this filly, and mothered her for a good 3 months. This just goes to show just how strong the maternal instinct is in most mares.

    • / Reply

      Are you serious??? How is keeping her in foal going to kill her? Horses are made to produce a foal every year. There is rarely complications during foaling, and if there is a glitch of any kind, nature aborts the foal early. This is why they get checked several times early in the pregnancy.

    • / Reply

      Do you *really* think the Mosses wish to “kill such a precious horse”? I recommend reading some of the other (very well-informed) comments about breeding and foaling.

    • / Reply

      Seriously????

      Google is a wonderful tool use it if you don’t believe the good doctor and all his years of education and experience.

      Kathleen, you’re right it’s odd that the most vocal are also the least informed.

      • / Reply

        So very true, posting information from the experts is very important as
        I am sure Dr. Holden is an expert in TB breeding has done research and
        been involved in the ART for his whole career.

        The expert know the facts, statistics and possiblities.

        Thanks again Lanes End, Dr. Holden and the Mosses.

        Great comments Margaret, Right on !!!!

  12. / Reply

    Thank you Dr. Holder for your answer to this question. Anyone who has not been around horses, let alone TB race horses, know nothing about these things. We learn so much from this site. Very informative.

  13. / Reply

    I have been around broodmares of various breeds and they will soon tell you if they dont want to be in foal, if they were living in the wild for example most mares would have a foal every year for most of there lives most without problems through foaling, they are an amazing creature. with horses if they are in foal weaning is generally less stressful on the mare and foal.

  14. / Reply

    Mares hardly know they’re pregnant for the first eight months of pregnancy, most of the growth takes place in the last three months of gestation. By that time, the first foal is long weaned and her body as long recovered from the trauma of foaling. Nothing at all cruel about it. You think mother nature would design a reproductive system that was harmful to the mother? Good grief. There’s a good reason for a mare (in the wild, in nature) to come back in heat and be re-bred right away. Her first foal might be lost to a predator. Why should she wait a year to come back into heat, then have to wait another year before the arrival of her next foal? In nature, any individual who is not reproducing is not doing its part to ensure survival of the herd and/or species.

    Face it, those lions need to eat too! In a way, the more the mares reproduce the less likely the lions would need to go after adults. Frequent breeding contributes to the survival of the fittest and strengthening of the species. The foals who aren’t eaten grow up and contribute their stronger and faster genes to the next generation. Slowpoke foals become lion food.

    Horse breeders aren’t breeding lion chow, of course, but the mares are designed for this and there’s no reason not to take advantage of it. Nothing cruel about it at all — they’re just letting the mare do what mother nature designed them to do.

    • / Reply

      I am sure he was, his mother taught him so very many skills in their 6 months together,
      she gave him self-confidence, security and a good sense of himself.

      THANK YOU ZENYATTA FOR RAISING SUCH A WONDERFUL SON,

      LOOKING FORWARD TO YOUR “GREY FILLY” BY TAPIT (MY WISH).

  16. / Reply

    What an excellent post. Great question, Gail and how lucky are we to have a veterinarian as the answer expert. I hope having someone like Dr. Holder provide the answer can help those who have trouble accepting that it’s fine, ok, even the best way to do things for the mare, to understand about the practice of mares having foals in successive years.

  17. / Reply

    I knew it was happening- It’s time for the Prince to join his buddies. Knew it when the Moss’ said they were going to visit…. Thank you, Lane’s End and Dr. Holder for your very thorough explanation regarding breeding and how mares actually flourish being pregnant.

  18. / Reply

    What’s the word on weaning……….did they already do it? The latest pictures seem to have been from the weekend, so I assume he was weaned Sunday night/Monday morning??? I’m sure Zenny will look for him for a day or so, but ‘mom and dad’ are visiting, so I’m sure she is doing quite well and is quite happily munching carrots and mints.

  19. / Reply

    Everytime these topics come up, weaning and breeding, people get so upset. I get it and as humans we get a little sad; however, I’m choosing to leave it all to the experts on this site and at Lane’s End. As I’ve said many times, I know nothing about breeding horses. I do know Zenyatta’s connections would never, ever do anything to hurt her or her offspring! Just the fact that Ann and Jerry were there during this time speaks volumes! The only sad thing to me is how fast time goes by. Can’t wait for all the excitement when Zenyatta gets close to her due date again! Also, it’s so exciting that we are getting so many new posts and photos. Thank you again to all the connections and all the expert Zenyatta fans!

    • / Reply

      It upsets me when people refer to her as a cash cow. These people know nothing about horses, or about the Mosses……..you’re exactly right…..the fact that they are with Zenyatta speaks more to their character than any article written about them. These people love their horses, and I’m quite sure Ann would have Zenny in the back yard if were at all feasible. Their choices in trainers and ranch facilities have shown just how much they care.

      • / Reply

        In fact, according to an ESPN article from 2010, her Ann was serious about keeping Zenny in her backyard but realized this life she now enjoys is what is best for her. The Mosses are class acts in every way.

  20. / Reply

    Wonderful article! I’m hoping that this serves to inform those who do not understand about breeding mares.

    Also, happy to hear that the weaning went well. Figured it was happening since ‘mom and dad’ are there. It should be very clear by now that the Moss’ truly love Zenyatta and take the best care of her (and all their horses for that matter). Hats off to them for being caring owners!

  23. / Reply

    Yeah!!! The Prince is on his own with other colts his age. You took it like the champ you are! Zenny, you did wonderful! Proud of both of you! Now, shortly, all the aunties and uncles will start pacing once again!
    For those that want to bicker about her being bred and the Prince being weaned, I suggest that you take to heart what the Experts are saying. I’ve been around many many broodmares, worked with the breeding etc… They are fine! If the mare’s body isn’t ready to be pregnant, she’ll abort or re-absorb the zygote.
    This is a milestone that should be celebrated and not looked upon as something negative. Someone said earlier on here that you are killing her. Wow, you really need to educate yourself and pay attention to how Ann and Jerry care for their horses and how special and loved Zenny and the Prince truly are!
    I also saw a comment on fb asking what he’ll bring in the sale ring. It’s already been established that he will NOT be sold!
    Ok, I think I’m done venting now. It just gets old with the same people saying the same darn thing. Or second guessing the EXPERTS, MOSS”S and Lane’s End staff!
    Have respect people!

    • / Reply

      VERY WELL SAID, HEIDI.

      ANN AND JERRY SAID MANY MOONS AGO THAT 12 ZENYATTA WOULD NOT BE
      SOLD. IT IS POSSIBLE THEY WILL KEEP ALL OF HER OFFSPRING TO DEVELOP
      A BREEDING FAMILY; THE ZENYATTA FAMILY.

      MAYBE HER GRANDCHILDREN OR GREAT GRANDCHILDREN WILL GO TO THE SALES RING, BUT THAT WILL BE A LONG TIME COMING.

  24. / Reply

    Thank you for a great question with an expert answer that is easily understood. Being in love with Zenyatta has not only helped form bonds of friendship with others who love her, it has enabled me to deepen my knowledge of horses in general, too. Thanks for another great lesson, Team Z, Lane’s End and Dr. Holder. In my struggle not to anthropomorphize Queen Z, I feel sad about the weaning today, but the other side of me realizes it was done just as nature unfolded. Hopefully we will be continually updated as our young prince grows and Lane’s End will share with us some of his adventures with his new buddies in the big boy pasture – lol!

      • / Reply

        Celeste: very well said. This site has been so wonderful in teaching me more about horses – you folk that actually own one are so, so lucky, but I feel really blessed that you are all so willing to let us know more about these fantastic creatures.

      • / Reply

        LOVE IT TOO, they are now big boy’s on their way to learning gound manner,
        how to walk with a human, play with each other and finally become the racehorses they were bred to be.

  25. / Reply

    Thanks for all the pictures and the info Hopefully those that were less then knowledgeable about breeding and weaning have learned something about this subject How sweet that the Moss’s came for this right of passage for Zen and Z12 And that the weaning went well Time for the count down to begin for Z13 And hoping for timely updates on Z12 Just love watching him grow

  26. / Reply

    Soft kisses on your soft nose, Zenny . Your little guy is now on his own so to speak and you have done well with him. What a glorious mother you are…I hope we continue to get regular updates on you and the Prince.

  29. / Reply

    Updated comments from past blogs, that were missed by RN me.

    Judy B – Love the links to Fourstardave, what a wonderful horse, to die of a heart attack
    while under light training tells it all of his dedication to the sport.

    TC, GP – great jokes !!!

    Rosemary – Love the trivia question, will send you and e-mail for a prize. Knew Scott Hazelton’s dad was a trainer, but did not know his name.
    Great call Eveline !!!!

    Sue Fredrick – Love the RN Book of Manner, just like the RN Games a real HOOT and HOLLER !!!!

    GS, You do a great job with your current reading glasses. Yes, google, The vault
    and thoroughbred racing.

    • / Reply

      These are the lessons we can take from her. In every situation she handles herself like a pro. From the time of her foaling with Don Robinson and schooling with the Mayberrys and finally ending at Barn 55, Zenny has only known love and responded to it in kind. She has set a new standard, we are blessed to know her.

      • / Reply

        Sue,

        I think it is much more than that, she has a very special temperment that has only been enhanced by the Mosses, but “she does demand a level of care for herself
        that has always been met”. Her temperment was developed through her female
        family from “V” on back to Erick Kronfeld’s other mares in her line.

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