Page 107 - June 2017

Introduce new mares to the group slowly to prevent problems or injuries down the road. Put her in a separate stall or paddock next to the other mares so they can get acquainted, and gradually increase the time they spend together before turning her out with the other broodmares.
pecking order,” says Sheerin. You can acquaint the new mares to one another gradually and get the new individuals gradually acquainted with the mare or mares she will eventually be living with during turnout time.
“If the broodmare band is living outside all the time, ideally you should still keep the new mare in the barn for a while in order to get her gradually adjusted to her new life,” Sheerin says. “A little bit of turnout in a small paddock, increasing the size of the paddock and the number of mares she is with, and then turning them out into the bigger herd makes the transi- tion easier for that mare.
“In that type of situation, however, you need to keep a very close eye on them to make sure the new mares are getting enough to eat. If they are the lowest ones on the pecking order, do they get chased away from the feed? You might need to use some different strategies to allow them to eat—perhaps feed in a differ-
ent paddock or bring them in for feeding—so they don’t lose body condition. The goal is to get them transitioned from lean, mean racing machines to mellow broodmares with some body stores of fat,” he explains.
The lean, extremely fit racehorse is not programmed for fertility and reproduction. “We will be putting those mares under lights before winter, so we’ll be bringing them into the barn at the beginning of December to go under lights. This is a time you can increase their feed, especially if you are feeding each mare in a stall, to increase their body stores and body condition. You want them to be in a posi- tive energy balance when it’s time to start the breeding season,” he says.
Each mare/filly is a little different in their needs. “This is true for all broodmares,” says Sheerin. “You have to treat them as individuals as much as possible within the management scheme that you have. Some need more feed than others. You also should deal with any stall vices or lameness issues. Horses out in the
big herd must be sound enough to function normally. If a mare has a lameness issue, you need to make sure it’s not impacting her ability to get to feed and water.
“Those groups of mares that come off the track in the fall are not too difficult to transi- tion and manage because you have the time
to work with them. The ones that are more problematic are those that suddenly get turned into broodmares during the breeding season— either because they have injuries, are not racing to their potential, or have some other issue. When that decision is made to turn them into broodmares, you don’t have the luxury of time like you do with a mare that starts this transi- tion in the fall.
“For the mares that are suddenly sent to be broodmares, in addition to letting them calm down, you also need to get them cycling. If it’s February or March, depending on the housing situation they were in as racehorses, they may not have had enough light stimulation and may still be in anestrus and not cycling. Then, you are behind the eight ball because it’s too late
to put them under lights. They will come into heat naturally in April on their own, so starting them under lights in February or March won’t move them up at all,” he explains.
“With those mares, you may have to con- sider using hormone therapy to try to get them cycling sooner. If they have been on Regumate or some other form of progesterone while they were racing, they need some time to get that out of their system. And, there may be other drugs they’ve been on that may impact their ability to cycle. This takes time to clear out of their bodies,” says Sheerin.
Since the racehorse is not programmed for fertility and reproduction, placing her under lights and increasing her feed before winter will help her start to cycle.
Some mares don’t start cycling normally because they are so athletically fit, with no extra body fat. “This is similar to what sometimes occurs in human athletes, such as marathon runners. You may also see absence of cycling in race mares that are stressed or over-conditioned and thin. This usually resolves with time, (and let-down from racing to more normal activity) but the question is how long will it be? Will it be a month or six months? It will vary from mare to mare. Some of them will resume cycling when the training stops and the groceries increase and the stress decreases. They turn around in a rela- tively short time, while others take six months or so to get to that point. By then, the breeding season is over. But, they will be okay for the fol- lowing breeding season.
“Some mares appear to be cycling and ovulating normally, but don’t get pregnant when bred—for many reasons. Perhaps they were receiving some type of drug or supplement that impacted their ability to become pregnant, even though it didn’t have much impact on the way they cycled. Or perhaps they still have enough residual stress to have a negative impact. Stress is something that we know has an influence, but we don’t know enough about its impact in mares. We know the impact stress has in other species on the reproductive cycles, but there hasn’t been much study on this in mares.”
The age of the mare will also make a differ- ence in how she will be handled. “Her age will be a factor and we may end up dealing with older maiden mare syndrome and some other issues that have to be addressed,” says Sheerin. Older maiden mare syndrome is when a mare that has never been bred has an abnormally closed cervix despite being in strong heat, pre- disposing her to inflammation and infertility.
“The broodmares may be in huge pastures, with run-in sheds, and bred when they start cycling on their own in April. Or, it may be a more confined situation where each mare has a stall and goes in and out, and the mares are put under lights—with more intensive manage- ment,” Sheerin says. “I think transitioning racehorse mares will further benefit from more management rather than from less manage- ment. With more direction, the mare won’t be subjected to such an abrupt change. You will also be able to identify problems a bit easier and quicker and be able to deal with them faster in this situation since it’s more hands-on and you are monitoring the mares more closely.”
Each facility and mare management program will be a bit different, of course, so some of these things will be handled differ- ently depending on how much space there is, how much help there is, and so on. The main things in transitioning mares from racing to the broodmare band, however, are socialization and getting them used to the new routine.
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equine health